1. Canning for Home Food Preservation
Katrina Levine, MPH, RD, LDN
NC State University
NC Cooperative Extension
May 2016
Introduce self

2. Overview History of Canning Canning Safely Canning Processes
Health and Nutrition
Questions
Image:

3. Food Preservation Fruits Vegetables Meats Poultry Eggs
Food preservation has been around for a very long time, and we historically used it to store all kinds of foods when fresh, in-season foods are scarce. We preserve everything from fruits and vegetables to meats, poultry, and eggs.
Canning is only one way of preserving food. In this series, you’ll also hear about fermentation and pickling, but freezing, drying, curing, and smoking are other ways of preserving food. Today I’m going to talk mostly about canning.
Images:
Dried fruit:
Cabbage:
Salt pork:

4. 12,000 francs, in 1809 when he submitted his method of “food in glass bottles.”
Nicolas
Appert
Does anyone know who this is?
Nicolas Appert was a French chef, confectioner, and distiller. He’s known as the “father of home canning” because he invented the basic method of perserving food in airtight glass jars. He called it “food in glass bottles”.
How much do you think he made off of his method of preserving food in glass bottles?
12,000 francs in 1809 = $25,000 today
I’m sure our wonderful librarians here could direct you to more information about him.
Source:

5. Canning history
Nicolas Appert used glass jars sealed with wax and reinforced with wire. It took 14 years to develop.
Peter Durand replaced the breakable glass bottles with cylindrical tinplate canisters
Louis Pasteur provided the explanation for canning when he was able to demonstrate that the growth of microorganisms is the cause of food spoilage.
He used glass jars sealed with wax and reinforced with wire. The wax melted to create the seal, similar to the coating around the edge of the lids of today’s home canning jars.
It took him a long time – 14 years – to develop the method. I don’t know about you, but I’m not patient enough for that!
Later that year, an English inventor named Peter Durand took Appert’s method one step further – he replaced the breakable glass bottles with cylindrical tinplate canisters. This was the foundation for today’s commercially canned foods metal cans, just like you’d buy at the grocery store.
Sources:
B. Lund, et al. Eds. 2000

6. Foods packed into sealed, or airtight containers.
Acidic/acidified foods heat sufficient to destroy vegetative microorganisms
Foods packed into sealed, or airtight containers.
Low acid canned foods are heated under pressure at temperatures of °F ( °C).
How did he finally get it to work?
1) He used heat. Heat kills microorganisms that can cause spoilage and foodborne illness.
Foods that are acidic or have acid added to them can be heated in jars submerged in a pot of boiling water. This heat is enough to destroy microorganisms that can cause foodborne illness and spoilage. The process, which we’ll talk about in a little bit, creates an airtight sealed container.
Other foods that are low in acid need more heat and pressure to destroy those microorganisms (because there isn’t enough acid to help). These foods must be heated in a pressure canner to temperatures between 240 and 250 F. We’ll also talk about this method later.
2) His process removed the air from the bottles. The canning process pushes out air that gives microorganisms an environment to grow. Oxygen can also cause food spoilage through a chemical process called oxidation.
3) It created an airtight, sealed container. This prevented new microorganisms and oxygen from getting in the jars.
These basic principles haven’t changed dramatically.
We still need enough heat to destroy microorganisms
We still pack foods into sealed or “airtight” containers.
Canned foods are heated under steam pressure at temperatures of F

7. Majority of home canners have reported not following science-based home preservation methods
Receive much of their home preservation information through friends and family
Only 45% of respondents thought that home canned foods could be spoiled without obvious signs of spoilage
Has anyone ever canned food before? What do you can or preserve?
Home canning continues to be a popular means of preserving food at home (Andress et al., 2002).
Fruits and vegetables make up the majority of home preservatives
Meats (especially game) and fish are also preserved.
Where did you get your recipe or method? [Probing: Old family recipe? Book? Blog?]
In 2005, a national phone survey was done on home canning.
58% of home canners are between years of age
27% are 65 and over
15% are under 35
(D’sa et al., 2007)
The results of this survey tell us that most home canners report not using science-based methods for preserving food. As many of you suggested, much of their home food preservation information comes from friends and family.
3) Now let me ask you another question. How do you tell if canned food is “bad” or “unsafe”? [Probing: Look? Smell? Taste?]
Only 45% of people surveyed about this thought that home canned foods could be spoiled if there weren’t obvious signs of spoilage, like mold growth or an off smell. In other words, more than half of people seem to think that there needs to be obvious signs of spoilage for foods to be spoiled.
Brace yourself – this news could change your life. When it comes to canning – and food safety in general – most of the time it’s what we can’t see, smell, or taste that matters and could make us sick. I’m talking about harmful bacteria that can cause foodborne illness.

8. What Makes Canned Food Unsafe?
Causes botulism poisoning
Found naturally in soil and water.
Produce heat-resistant spores that only destroyed by pressure processing.
Spores need
oxygen-free environment
low-acid food
temperature between 40ºF to 120ºF
relatively high moisture
The main thing we worry about with home canned food is botulism. Has anyone heard about it before, or know anyone who’s had it?
We’re not talking about cosmetic injections – we’re talking about getting it from food. It’s serious - even a bite of an improperly-canned food can kill you. Botulism affects the nervous system and can cause paralysis and death if not treated immediately. Symptoms take between 6 hours and 10 days to show up and include double or blurred vision, drooping eyelids, slurred speech, and difficulty swallowing and muscle weakness % of people who get botulism die.
It’s caused by a toxin produced by the Clostridium botulinum bacteria. Both the toxin and the bacteria themslves are tasteless and odorless. These bacteria are naturally found in small amounts in the soil, which is how they get onto food. They become a problem in home canned foods that aren’t canned properly because if the bacteria and their spores aren’t killed during the canning process. Spores need a moist, oxygen-free, and low-acid environment between 40 and 120F to grow. Spores do not grow in high-acid foods and are killed when low-acid foods heated long enough at a specific temperature.
They can form these spores that I just mentioned, which are kind of like seeds for bacteria. They’re not dead, they’re just not really alive or growing. These spores aren’t killed by normal cooking temperatures and can become a problem in that anaerobic canned food. When the temperatures are right they wake up and start making bacterial cells, which then start making this toxin. So over time, spores that survive in an improperly canned food item can turn into botulinum toxin.
If canning is done properly, the spores and C. bot cells will be killed in one of two ways:
By a combination of acid and heat, as you’ll see with boiling water canning, or
A combination of pressure and higher heat, as with pressure canning
Sources:

9. 12 were linked to 2 pruno outbreaks
2012 CDC surveillance
160 cases
25 cases foodborne
12 were linked to 2 pruno outbreaks
Yes, it’s serious. But how common is it to get botulism from eating a home canned food product?
Data from the Centers for Disease Control and Prevention – which only includes cases that were reported – tells us that in 2012 there were 160 reported cases of botulism in the U.S.
25 of those were caused by food, and 12 were from a specific food called pruno.
I had never heard of pruno until my boss told me about this outbreak. That delicious looking stuff in the bag this guy is holding is pruno, a home-made alcoholic drink made illegally in prisons. It’s also known as prison wine or jailhouse hooch, juice, or brew. I’m not sure I’d be desperate enough to drink that stuff.
Ok, well not that many of us are probably going to make pruno. We’re going to make canned foods, so let me give you some examples that might hit closer to home.
Source:

10. Clostridium botulinum Ashe County, North Carolina
Only one bite of improperly-canned carrots led to
11 weeks in the hospital for one woman
Let’s start right here in our home state of North Carolina.
Almost exactly a year ago, a woman in Ashe County (towards the mountains) canned some carrots. She took one bite and didn’t even swallow it, but decided it tasted off and spit it out. But it was enough to give her botulism and send her to the hospital. She couldn’t breath and had to be put on a ventilator. She spent 11 WEEKS – not days – in the hospital. Do you have time to take 11 WEEKs off of your job or responsibilities? Yeah, me neither.
And she was lucky that she noticed an off flavor, because the taste wasn’t because of the toxin. They probably tasted bad because the method she used – which wasn’t pressure canning - left some other bacteria alive that cause off flavors.
Source:

11. Clostridium botulinum Lancaster, Ohio One death and 24 illnesses
Linked to a church potluck
Canned potatoes in potato salad
Here’s another example. Just last year in Ohio, one person died and 24 others got botulism from potatoes that weren’t canned properly. They were used to make a potato salad served at a church potluck. Potatoes are a low-acid food and the wrong method – a boiling water bath instead of a pressure canner – was used to can them.
In this one, a lot more people were affected. In fact, it’s the largest botulism outbreak in 40 years.

12. Pickled beets, that weren’t actually pickled linked to 3 Oregon illnesses in 2012
One last example is an outbreak from “pickled” beets in Oregon several years ago that gave 3 people botulism. As it turns out, the beets weren’t actually picked, or acidified, which is why people got sick. This one shows that other methods of food preservation using airtight jars – not just traditional boiling water bath or pressure canning – can cause botulism.
Juice counts, too.

13. How to Can Safely Credible, tested recipe
Pressure canner for low-acid foods
Test pressure canner dial gauge each year before use
Correctly operate canner
Check that lids seal
Boil and discard any food that may have the botulism toxin
Here are some basic tips for canning safely. We’ll go into each of these in a little more detail next.
Follow a credible, tested recipe – and follow it exactly.
Process low-acid foods in a pressure canner
If you have a dial gauge pressure canner, test the gauge for accuracy each year before you use it
Use your canner correctly – make sure you’re following the manufacturer’s directions for use and care
Check to make sure the lids seal in the appropriate amount of time. Otherwise the food won’t be safe to store at room temperature.
If you think there might be C. bot toxin in your canned food, detoxify the food before discarding. You can do this by boiling the food, because the toxin is destroyed by boiling even though the spores are not.

14. Process Food Properly Follow a credible recipe exactly
No substitutions!
The following slows heat penetration:
Extra sugar or fat
Oversized food pieces
Added thickeners
I asked you earlier where you got your canning information and recipes. One of the most important things is using a credible recipe and following it exactly. When I say credible, I’m certainly not trying to suggest that your great great grandmother or best friend isn’t credible. They may in fact be using a recipe from one of our trusted sources. I’ll share these with you at the end, and the recipes in these sources have all been scientifically tested to show that if followed exactly, the risk of getting botulism is basically non-existent (very very very low – there’s never zero risk for anything).
Following the recipe exactly as I just said is also important. There’s not point in the recipe being credible if you change part of it or don’t follow it exactly as it was intended. Adding extra fat or sugar, using larger pieces of food, or adding thickeners can cause food inside the jars to heat up more slowly – it slows the heat penetration. This would mean the processing time in the recipe wouldn’t be long enough, and there’s no good way for us to attempt to adjust that time without testing an entirely new recipe.
Following the recipe exactly still matters when it comes to nutrition. We get a lot of canning and food preservation questions at NC Cooperative Extension, and it’s part of my job to research and answer these questions. We get a lot of questions about substitutions for things like jams, jellies, and pickles because many people want to limit the salt or sugar in the recipes. However, the rule still applies – the recipe must be done as written. I know you all probably have questions about this, too, so I’ll spend some more time on this when we talk about nutrition.

15. Process Food Properly Processing times Use the right equipment!
Lots of factors affect
Heat-up and cool-down times in pressure canners are counted toward sterilizing value of the process. Never rush them.
Use the right equipment!
Pressure canner – low acid foods
Processing time, which is really part of the recipe, needs to be followed exactly. Each food and preparation style has its own processing time. It will also vary based on the jar size and your location (in terms of elevation). As altitude increases, the temperature decreases at a given pressure, so more pressure is needed at higher elevations. There are several guides for processing based on your elevation, and most recipes include processing times and pressures for different elevations.
Not processing long enough, called under processing, can lead to food spoilage and unsafe food. Processing too long, or over processing, can cause food to be overcooked. There are many factors that affect the processing time, and I won’t get into all of them for the sake of time, but the key thing to remember is that making even small changes in a recipe can affect the outcome, so just don’t do it.
Acidity of the food
Preparation style of the food
Composition of the food
- Viscosity
- Tightness of pack
- Convection vs. conduction transfer of heat
- Starches, fats, bones
Initial temperature of food as it is packed into jar
Temperature of processing
Size and shape of jar
We also have to respect those heat up and cool down times because they’re part of the process needed to kill bacteria. Don’t try to rush this, or it won’t work.
Using the right equipment, as we said before, matters too. We have to use a pressure canner for low-acid foods.

16. Unsafe Canning Methods
Open Kettle
Oven Canning
Dishwasher
Addition of Aspirin
Steam Canners*
Microwave Oven Canners
Do not use any of these methods to can because they are not safe. Also remember that a pressure cooker is NOT the same thing as a pressure canner. You CANNOT can food in pressure cooker.
Open kettle:
In open kettle canning, food is cooked in an ordinary kettle, then packed into hot jars and sealed without processing. The temperatures obtained in open kettle canning are not high enough to destroy all spoilage and food poisoning organisms that may be in the food. Also, microorganisms can enter the food when it is transferred from the kettle to jar and cause spoilage. (NCHFP)
Oven canning:
This can be dangerous because the temperature will vary according to the accuracy of oven regulators and circulation of heat. Dry heat is very slow in penetrating into jars of food. Also, jars explode easily in the oven. (NCHFP)
Dishwasher:
Processing canned foods during a dishwasher cycle can be dangerous. The temperature of the water during the cleaning and rinsing cycle is far below that required to kill harmful microorganisms. Thus the product will be under-processed and unsafe to eat. (Penn State)
Aspirin:
Aspirin should not be used in canning. It cannot be relied on to prevent spoilage or to give satisfactory products. Adequate heat treatment is the only safe procedure. (NCHFP)
Steam canning:
Atmospheric steam canners are used for processing naturally acid or properly acidified foods with natural or equilibrated pH values of 4.6 or below. They are not pressurized vessels used for processing for low-acid foods. (NCHFP)
In general, steam canners are not currently recommended because processing times for use with current models are still being researched. (NCHFP)
Sufficient studies and peer review have been completed that we are now able to say that as long as certain critical controls at various steps in the canning process are achieved, USDA and NCHFP process times for canning acid or properly acidified foods (pH of 4.6 or below) at home with properly research based recipes and procedures can be used. (NCHFP)
Microwave canning:
Microwave oven cannot be used for home canning. Microwaved food reaches 212°F but heating is not uniform. There is also a danger of explosion of the jars within the microwave oven or as food is being removed from the oven. (Penn State)
Sources:
*Research shows steam canners are safe for properly acidified foods as long as certain critical controls at various steps in the canning process are achieved; research is still ongoing.

17. Canning Basics
Now I’m going to go through some of the basics of the canning process.

18. Basics of Canning
Food is placed in a jar and heated to a temperature that destroys targeted microorganisms.
Heat also inactivates enzymes that cause spoilage.
Air is driven from the jar during heating. As the jar cools a vacuum seal is formed.
We already talked about this earlier, but just to recap, this is how canning works.
We put food in jars and heat them to a certain temperature to destroy specific microorganisms – the ones that cause illness.
The heat also inactivates the ones that cause spoilage.
Air is driven out of the jar during heating. As the jar cools, a vacuum airtight seal is formed.

19. Two Methods of Canning Boiling Water Canning Pressure Canning
High-acid foods
Acid kills C. botulinum spores
Heats to 212°F – destroys spoilage organisms and some foodborne pathogen
Low-acid foods (and some high-acid foods)
Heats to 240°F to kill C. botulinum spores (not enough acid)
We’ve already touched on this a little, so let me go into more detail on the two methods of canning.
Boiling water, or boiling water bath canning is used for high-acid foods. It’s basically submerging loosely closed jars of food in a big pot of boiling water.
The second method is pressure canning, which can be used for either high- or low-acid foods, but is required for low-acid foods. A pressure canner is a special pot with a lid that can be locked tightly. There’s a gauge on the lid that either looks like a small knob or that has a dial for showing the pressure.
There are specific reasons why we have two methods.
We do need to heat canned foods to at least 212F (at sea level) because it destroys those spoilage organisms, including yeasts, molds, and most bacteria, and some types of bacteria that cause foodborne illness, like Salmonella and E. coli. This is what boiling water bath canning is good for.
Pressure canning is required for low-acid foods is because there’s no acid to kill the C. botulinum spores, which means that the temperature has to get even hotter than boiling to kill them. The only way we know to do this in a home situation is to use a pressure canner. Pressure canners work by creating pressure that causes temperatures inside the canner to increase to very high numbers. Research tells us that low-acid canned foods need to reach temperatures of F to kill C. botulinum spores. They’ve got to stay at these temperatures for specific periods of time so we know that the spores don’t survive.
Both can be done safely as long as the right procedure is followed for each and they are used for canning the right foods.

20. Food Acidity High (pH ≤4.6) Low (pH > 4.6)
All fruits except figs, tomatoes, and melons
Fermented pickles (sauerkraut)
Acidified foods (cucumber pickles)
Low (pH > 4.6)
All vegetables except rhubarb
Meats
Poultry
Seafood
Soups
Mixed canned foods (low-acid + high-acid)
In canning and food preservation, high acid means a pH of below or equal to 4.6. If you’ve taken some basic science classes, you’ll remember that acidic foods have low numbers on the pH scale of 1 to 14. A pH of 7 is considered neutral – water is the typical example.
All fruits are high acid foods except for figs, tomatoes (which are technically fruits), and melons.
Fermented pickled foods, such as sauerkraut or fermented cabbage, are also high acid. Acids are naturally created by lactic acid bacteria during the fermentation process.
We can also make non-acidic foods high acid by adding an acid to them, or acidifying them. Pickled foods are one example. The acid that is added is mostly vinegar.
Low-acid foods, on the other hand, have a pH of above 4.6.
Low-acid foods include:
all vegetables except rhubarb
Meats and poultry
Seafood
Soups
Mixtures of canned foods, such as salsa (low-acid = peppers, onions, garlic; acidic = tomatoes)

21. Used for high-acid foods and acidified foods
Boiling Water Bath
Used for high-acid foods and acidified foods
Now I’m going to do some demonstrations. First, I’ll demonstrate how to use a boiling water bath canner as I go through the steps. Then I’ll give some background information on pressure canning and demonstrate how to use a pressure canner.

22. Using a Boiling Water Bath Canner
Sterilize jars (if < 10 min processing time)
Have water simmering or hot in canner, high enough to cover jars (about 1-2i nches)
Wipe rim of jars and adjust lids
Lower jars slowly on rack in canner.
If you’ll be making anything that has a processing time under 10 minutes, then you’ll need to sterilize your jars and lids first. This is important because the jars aren’t being heated long enough to kill any microorganisms that might be in them already (mostly ones that cause spoilage).
To sterilize, put the empty jars and lids on the rack in the canner, then fill the canner and into the jars with hot water to an inch above the jars. Bring to a boil and boil them for 10 minutes if your elevation is 1,000 ft or below (plus an additional minute for each 1,000 ft of elevation). Remove and drain the jars one at a time when they’re done. It’s a good idea to save the hot water in the canner to use for processing the filled jars.
When you use a boiling water bath, you need to start with enough water to cover the jars, which will be about 1-2 inches of water. Heat it to simmering in a canner or very large (about 20 quart) pot. There are slight differences in the water temperature depending on if you’re doing raw pack or hot packed jars, which we’ll talk about a little later.
It’s important to wipe off the rims of the jars so that there won’t be an food on the rim to keep a tight seal from forming. Put on the two piece lid and tighten it, but not so much that it’s hard to loosen. We call this “finger tight”.
Source:

23. Using a Boiling Water Bath
Add more hot water if necessary, once jars are in canner. (Don’t pour hot water directly onto raw-packed jars).
Count processing time when water returns to a boil.
Remove jars to a padded surface.
Cool away from drafts, 12 to 24 hours.
Check that lids sealed.
Have the rack setting in the bottom of the canner and slowly lower the jars in slowly with your jar holder tool.
Add more water if it’s not at least an inch above the jars.
Wait til the water returns to a simmer before you start timing.
When the jars are done, you’ll want to put them carefully on a towel or padded surface out of the way and not near any drafts to let cool. Put them somewhere where they won’t be in the way, because you can’t touch or move them for hours. This is because the lids are still sealing, and moving them could disrupt the seal. If you do have to move them for any reason, you’ll have to refrigerate them and they won’t be shelf-stable.
After hours, check to make sure the lids have sealed. You can test by pressing in the center of the lid – if a vacuum was created, the lid won’t move or pop when you press it.

24. Used for low-acid foods
Pressure Canning
Used for low-acid foods
Now let’s talk more about pressure canning.

25. Using a Pressure Canner
Assemble, clean, and test before use.
Put jars on rack in 2 to 3 inches of simmering or hot water.
Put lid on canner with weight off or petcock open.
Exhaust canner for 10 minutes.
Close vent or petcock.
Start counting processing times when correct pressure is reached.
It’s important to make sure your pressure canner has been assembled, cleaned, and tested before using it.
Some parts might need to be assembled, so read the manufacturer’s directions before using.
Reading the manual will also help you become familiar with the parts and functions of the canner. Not all canners are the same, although they serve the same purpose.
Clean your canner before using to remove any oils.
Lightly coat the gasket, which is the rubber ring around the inside of the lid, and lugs on the canner bottom with cooking (vegetable) oil.
Before EACH use, make sure the vent pipes are clear and open.
Canner testing – who to recommend?
To use your pressure canner, start out with 2-3 inches of simmer or hot water in the canner. Again, there are differences in the water temperature for hot versus raw packed jars.
Wipe the rim of the jar and secure the lids as with the boiling water canner
Then use the jar lifting tool to slowly lower the jars into the rack on the bottom of the canner.
Put the lid on the canner, making sure to leave the weight OFF or the petcock (the release vent) open.
Let the water in the canner simmer for about 10 minutes. This gets out all of the air and…We call this “exhausting” the canner.
Close the vent or petcock. This will prevent air from escaping, which will increase the pressure inside the canner.
When the correct pressure is reached (depending on your recipe and elevation), start timing for the processing time. For weighted gauge pressure canners, which have a knob that’s placed on top of the canner after that first 10 minutes, you’ll want to hear a constant knocking or rattling noise, kind of like a mentronome. For dial gauge pressure canners, just watch the dial until it is consistently at the right pressure.

26. Using a Pressure Canner
Turn off heat at end of processing.
Let pressure drop to 0 psi naturally.
Wait 2 minutes after pressure drops to 0 psig.
Remove weight or petcock.
Open canner. Watch steam!
Remove jars to padded surface or rack and cool 24 hours, undisturbed.
Check that jars have sealed.
When you’re done processing, turn off the heat. DO NOT try to open the canner!
Wait patiently until the pressure drops to 0 psi naturally – DO NOT try to speed up this process in anyway! You’ll know the weighted gauge is at 0 or close to it when the knob stands still.
After you’re at 0 psi, wait another 2 minutes before attempting to open the lid. Some canners won’t even let you try – they have a security lock in place that locks the lid until 0 psi is reached. Check to make sure that the locks in the handles have been released before trying to open.
Remove the weight or petcock.
Open the canner lid slowly AWAY from your face because a lot of steam will rush out.
Use your jar lifter to remove the hot jars to a padded area or rack out of the way, just like for the boiling water processed jars. Remember not to touch or move these, either, for 24 hours so they can cool.
Like with boiling water canning, check to make sure the lids have sealed after 24 hours.
Image:

27. Testing for Seals Listen for “pop”
Lid curved inward, won’t move when pressed
Clear ringing sound when tapped
How do you test to see that jars are sealed?
There are basically three ways.
1) Listen for a popping sound as jars begin to cool.
The lids will curve down or inward toward the jar and will not move when pressed.
If you tap on the center of the top with a metal spoon, you will hear a clear ringing sound rather than a dull thud.
[Activity: Have some sealed and unsealed jars of food. Let audience practice checking for seals.]
Source: “Canning At Home – The Basics” presentation by Judy A. Harrison (available from
Image (seal):

28. Canning Jars and Lids Jars Lids Approved canning jars
Clean, sanitized if <10 min processing time
Free of nicks, cracks, rough edges
Lids
2-piece
Cannot reuse flat part
Follow manufacturer’s directions
The jars and lids are equipment just like the canners, so using the right ones is important for safety and quality, too.
Jars:
Check jars for nicks, cracks, and rough edges.
Wash in soapy water, rinse well, and keep hot.
If food is processed for less than 10 minutes, need to be sterilized.
Do not use single-use jars, such as mayonnaise and tomato sauce jars, to process food at home.
Lids:
Use two-piece lids.
Flat lid cannot be reused but the ring band can.
Follow the manufacturer’s instructions for treating them.

29. Preparing and Packing Food

30. Raw vs. Hot Pack Raw pack Hot pack
For food that looses shape when cooked
Put raw foods in jars, pour hot water over
Put in warm or hot water
Hot pack
For most foods
Food cooked before packing
Put in simmering water
I mentioned earlier raw packing and hot packing.
Using the raw pack method for preparing food is good for foods that lose their shape when cooked….
Raw foods are placed directly into jars and then boiling hot liquid is poured over the food.
You’ll want to pack the jars firmly, but not crush the food.
Then carefully add the jars to a canner with warm water to avoid having the glass break from heat shock.
Then just follow the rest of your credible recipe as directed.
Hot packing is preferred for most foods. In this method, food is cooked in liquid before packing. Cooking liquid is then poured over the food in the jar
Hot packing definitely has some advantages:
Fewer jars are needed
There’s less floating food and better color and flavor
Foods are easier to pack
The heat from cooking helps kill some microorganisms.

31. Headspace
Space between the inside of the lid and the top of the food or its liquid.
Check recipe for directions
Usually:
1/4” for jellies
1/2” for high-acid foods, such as fruits, tomatoes, and pickles
1” to 1-1/4” for low-acid foods
After filling the jars, you’ll want to pay attention to the headspace. Headspace is the space in between the inside of the lid and the top of the food or its liquid. Your recipe should give a specific headspace, because each food has a specific headspace. A lot of this has to do with how much the food will expand during processing. It’s less for jams and jellies because there isn’t much expansion, and it’s greater for low acid foods because they tend to expand. Green beans are a great example – they expand a lot during processing.
There’s a nice tool that comes with many canning kits that helps you measure headspace.
Problems with canning are often related to the headspace. I’m not going to go over all of them now, but we have a great handout that can help you troubleshoot canning problems and figure out what may have caused them. Headspace problems are included in this handout.
Too little:
Food may bubble out during processing.
Deposit on rim may prevent proper sealing.
Too much:
Food at the top is likely to discolor.
Jar may not seal properly, because processing time not long enough to drive all the air from inside the jar.

32. Before Sealing Jars Remove air bubbles.
Re-adjust headspace if necessary.
Wipe jar rims.
Adjust two-piece lids, fingertip-tight.
Finally, before sealing the jars, you’ll want to check for air bubbles. There’s a nice canning tool that can help remove air bubbles.
After you remove any bubbles, you may need to re-adjust the headspace.
As we said before, wipe the rim of the jars and put on the two-piece lids, making them finger tight.

33. Jams and Jellies

34. Equipment and Utensils
Boiling water canner
Large Saucepot
Food Scale
Jelly Thermometer
Jelly Bag
Spice bag
Kitchen timer
Skimmer
Slotted spoon
Funnel
Jars or containers
Before we get into the types, I want to briefly show you a list of the the equipment that you would need if you wanted to make jams and jellies. You’ll notice a boiling water canner at the top. The other tools help you measure and cook the fruit and fill and load the jars.
Jelly bag is for straining out the fruit pulp and seeds. Cheesecloth may not be fine enough to strain out things like strawberry seeds.

35. Types of Jams and Jellies
Jelly
Marmalade
Preserves
Conserves
Butter
These are the six classifications of soft spreads. Many of you may use them interchangeably, I know I used to, until I learned that they are actually different, and those differences matter (especially if you’re entering in a competition like the State Fair—I’ve seen people get disqualified because they entered their product into the wrong category).
There are specific definitions for each of these, but I’m going to summarize the key differences between them:
Jelly is clear with no pieces of fruit – it’s made from strained fruit juice
Jam has crushed or small pieces of fruit
Preserves have whole pieces of fruit
Marmalades are jams with pieces of citrus fruit or citrus peel
You can consider a conserve as a jam with two or more fruits, but true conserves contain nuts and raisins
Butters are pureed, strained, cooked fruit pulp, sugar, and spice mixtures. They don’t gel like jams and jellies.
------
Jelly:
Made from strained fruit juice.
Should be clear and sparkling.
Gelled enough to hold its shape outside the jar, yet soft enough to spread easily.
Forms sharp angle when cut.
Jam:
Made by cooking crushed or chopped fruits with sugar until the mixture will round up on a spoon.
Can be made with one or more fruits.
Should be firm but spreadable.
Does not hold the shape of the jar.
Preserves:
Fruits preserved with sugar so that the fruit retains its shape
Is clear, shiny, tender and plump
Syrup is clear and varies from the thickness of honey to that of soft jelly
Marmalade:
Tender jelly with small pieces of fruit or citrus peels distributed evenly throughout
Conserve:
Jam-like product made by cooking two or more fruits with sugar until it rounds up on a spoon or flakes from it
A true conserve contains nuts and raisins
Butter:
Cook fruit pulp and sugar to thick consistency
Add spices – amount and variety vary
Cook slowly after sugar is added until thick enough to round up on a spoon
Process pulp in a food mil and strain through a fine-mesh sieve

36. Essential Ingredients
Fruit
Pectin
Acid
Sugar
Jams and jellies have to have these 4 things:
Fruit
Pectin
Acid
Sugar

37. Fruit Provides flavor Furnishes pectin and acid for gelling
1 pound fruit = 1 cup juice
Use top quality fruit
First, they have to have fruit. Yes, even pepper jelly has fruit in it.
Fruit gives it flavor.
It also is a base for the pectin to bind with, and provides acids needed for a gel to form
In general, you need a pound of fruit per cup of juice
As we hear often when it comes to cooking and food, using better quality ingredients will give you a better product, so using top quality fruit will give you a better jam or jelly.

38. Pectin
Natural substance found in varying amounts in fruits that causes jelly to gel.
Slightly under-ripe fruit contains more pectin than fully ripe fruit.
When making soft spreads without added pectin, use ¼ under-ripe and ¾ ripe.
Pectin is a natural substance that’s found in varying amounts in fruits. It’s what causes the jelly to gel.
Under-ripe fruits have more pectin than fully ripe fruits, so choose slightly under-ripe ones for making jams and jellies.
If you’re making a soft spread like a butter, though, use mostly fully ripe fruit – ¾ ripe and only ¼ under-ripe

39. Pectin in Fruits High Low Tart Apples Concord Grapes Sour Blackberries
Cranberries
Currants
Gooseberries
Quinces
Sour Plums
Apricots
Blueberries
Cherries
Peaches
Pineapple
Rhubarb
Strawberries
Certain fruits have more pectin than others. Some of these are tart apples, concord grapes, blackberries, cranberries, and plums. Others have less pectin, including blueberries, strawberries, cherries, and peaches.

40. Commercial Pectin Liquid or powdered Purchase fresh each year
Advantages
More jelly produced from the fruit
Better color
Less chance of failure
Shorter cooking time
For fruits with less natural pectin, we have to add commercial pectin to get it to gel.
Commercial pectin comes in liquid or powdered forms and have different preparation instructions.
It’s important to purchase fresh pectin each year because it degrades over time and looses its ability to form a gel. It’s common to see an problem with fruit not jelling properly because old pectin was used. We’ve got some handouts on solving some common canning problems, and this is definitely on that list.
Commercial pectin has some advantages.
The jam or jelly gels better because more jelly is produced from the fruit
It tends to give jams and jellies better color
Because you’re adding a consistent amount of pectin (since we know the amount in fruit varies) , there’s less chance of failure
The cooking time is shorter

41. Acid Needed for gel formation. Under-ripe fruits have more acid.
Commercial pectin contains some acid.
The third critical ingredient, acid, is needed for gel formation. It works with the pectin to create the gel structure. If there is too little acid, the gel will never set; if there is too much acid, the gel will lose liquid (weep).
Under-ripe fruits not only have more pectin, they also have more acid.
Some commercial pectins have added acid also, which helps make a stronger gel.
Source:
Image:

42. Sugar Contributes to flavor. Helps in gel formation.
Serves as preserving agent.
Last but not least, there’s sugar. Sugar is important because:
It contributes to flavor. We probably wouldn’t want to eat any jams or jellies made from tart fruits like raspberries or cranberries if there wasn’t any sugar in them.
Nor could we make either of those two jams or jellies without any sugar - it helps in gel formation.
Sugar also helps to preserve the jam or jelly and make it shelf stable. We don’t always think about sugar as a way to preserve food, but it certainly can be if enough is used. Sugar likes water, so sugar molecules hold tightly to water molecules, which doesn’t leave any water for C. botulinum or other bacteria (since we know they need moisture to grow). Although jams and jellies are moist, that water is actually already married to the sugar (sorry, bacteria, that water’s taken).
One thing that I think many first-time canners don’t realize is exactly how much sugar goes into a jam or jelly. My first experience with making jams and jellies was making some raspberry jam a few years ago. There was more sugar than fruit – 8 or 9 cups of sugar to only 5 cups of fruit. So I know what you’re thinking. What about people who are trying to limit their sugar intake? Isn’t there a healthier way to enjoy our favorite home-made jellied fruit spreads?

43. Sugar Substitutes Sugar subs May cause flavor and structure changes
Light Corn Syrup
Honey
May cause flavor and structure changes
Use tested recipes
Do NOT reduce sugar amount
There is some debate in the nutrition world over which type of sweetener is “better for you,” but they all boil down to the same stuff nutritionally – those same two simple carbohydrate molecules, glucose and fructose.
Cane and beet sugar are the usual sources of sugar for jelly or jam. Light corn syrup and honey may be used to replace part of the sugar in recipes, but too much will mask the fruit flavor and alter the gel structure. If available use tested recipes that call for honey or corn syrup.
If using honey, make sure that the product is not being fed to an infant (<1 year old). There are currently no studies or evidence showing that the process for making jams and jellies with honey will kill the C. botulinum spores in the honey.
Do not try to reduce the amount of sugar in traditional recipes. Too little sugar prevents gelling and may allow yeasts and molds to grow.
Source:

44. Non-Nutritive (Artificial) Sweeteners
Do NOT sub for sugar
Recipe must specify an artificial sweetener or lower-sugar pectin product
Process per recipe instructions or option to refrigerate or freeze
Many people may who are limiting their sugar or carbohydrates may want to make preserved fruit products that are lower in sugar. One way to do this is by using non-nutritive sweeteners (also known as non-calorie or artificial sweeteners). Jellies and jams that contain modified pectin, gelatin, or gums may be made with non-nutritive sweeteners. Jams with less sugar than usual also may be made with concentrated fruit pulp, which contains less liquid and less sugar.
This is important: Non-nutritive or artificial sweeteners CANNOT be substituted for sugar. If you wish to use these, you must use a recipe that specifies an artificial sweetener or lower-sugar pectin product.
Two types of modified pectin are available for home use. One gels with one-third less sugar. The other is a low-methoxyl pectin which requires a source of calcium for gelling.
To prevent spoilage, jars of these products must be processed longer in a boiling-water canner. Recipes and processing times provided with each modified pectin product must be followed carefully. The proportions of acids and fruits should not be altered, as spoilage may result.
Another alternative is to make a lower-sugar jam or jelly (such as with non-nutritive sweeteners) but store it in the refrigerator or freezer. These products spoil at room temperature so they must be refrigerated or frozen. Refrigerated versions should be eaten within 1 month.
Source:

45. Health and Nutrition
All of this talk about sugar is a great transition into talking about the nutrition of home preserved foods and how it relates to our health.

46. Nutrition Antioxidants Phytochemicals “Good” bacteria (probiotics)
Sugar
Salt
Vitamin loss during cooking
Just like many other foods available to us, home preserved foods have their benefits and drawbacks. From a nutritional standpoint, we just mentioned one of the disadvantages of canned foods – the large amount of added sugar in jams, jellies, and pickled fruits (from the syrup). However, fruits often used to make preserved fruit products contain phenolic compounds, antioxidants, and anthocyanins that can be beneficial to health.
With foods that use salt as the preserving agent, such as pickled and fermented products, the high salt content can be a drawback. However, many of these foods have benefical bacteria (as in fermented foods). Although we can’t take out any of the salt from pickled and fermented foods, we can rinse them before using (although most people do not choose to do this).
It’s important to note that while many fruits and vegetables are high in phenolic compounds, antioxidants, anthocyanins, and vitamins like A, B and C, cooking decreases their content. While certain fruits and vegetables are a good source of these vitamins when raw, they may not be as good of a source after cooking. One study of fruit jams showed that for most fruits, the total phenolics, antioxidant activity, and anthocyanins decreased after processing and (Castrodale et al. 2010). Strawberry jam had the greatest antioxidant activity compared to cherry, apricot, fig, and orange jams. Berries are known for their high antioxidant activity, so it makes sense that they had a higher amount.
Tomatoes are another example. In their raw form, they are high in vitamins A, B, and C. Cooking reduces this vitamin content. Despite the vitamin loss from cooking, though, canned tomatoes have shown strong evidence of other health benefits. Tomatoes are also a good source of the phytonutrient lycopene, which has been shown in many studies to help prevent prostate cancer, among. Salt is typically only added to canned tomatoes for flavoring, so by omitting or reducing the salt for flavoring, canned tomatoes can be a very healthy food.
Further research shows that only looking at what happens during processing still doesn’t give the complete picture. Storage time and conditions matter. This is what they found in the study with the jam – that the phenolics, antioxidant activity, and anthocyanins generally decreased during storage (Castrodale et al. 2010). But when compared to frozen foods, the oxygen-free environment in canned foods means that the nutrients are less likely to deteriorate over time. With frozen foods, there is greater nutrient loss over time during storage. (Rickman et al., 2007)
There is also the option of choosing frozen vegetables or freezing your own over canning. Commercially produced frozen vegetables are picked at peak freshness and frozen without preservatives (occasionally some contain salt for flavor). The nutrient quality of a frozen vegetable may be superior to that of a local fresh one depending on how much time has passed between harvest and when you use the fresh item. Frozen fruits may have added citric acid or added sugar to preserve quality (typically color and flavor). A healthy diet can include frozen as well as canned and fresh produce.
PERSONAL OPINION: As I mentioned, I’m a registered dietitian, so nutrition is as important to me as safety when it comes to food. When it comes to most cooking, I fully believe in and regularly practice modifying recipes to make them healthier or to suit my preferences. But this is one area where I don’t believe people should try to make substitutions or stray from the recipe. If reducing your sugar or salt intake is important, you may want to consider having smaller portions of your favorite jellied or pickled product, or cut back on other sources of sugar or salt in your diet or meal. Or, you could use a tested recipe for a lower-sugar or salt product. The National Center for Home Food Preservation has a collection of these reduced salt and sugar recipes. I’ll share their website with you before we finish today.
Sources:
Rickman, Barrett, and Bruhn. J Sci Food Agric 87:930 – 944 (2007)
Howard, L. R., Castrodale, C., Brownmiller, C., & Mauromoustakos, A. (2010). Jam Processing and Storage Effects on Blueberry Polyphenolics and Antioxidant Capacity†. Journal of agricultural and food chemistry, 58(7),
PROS
CONS

47. Weighing the Pros and Cons
There are a lot of factors to consider when deciding whether or not to can your own food. Nutrition is only one of these factors.
Many people choose canning because they have more control over what goes into their food. Although which ingredients you use to can may not be flexible (you should always follow a tested credible recipe), people can choose where they get their ingredients. We’ve talked about the risk of foodborne illness from canning, and purchasing foods from safe sources is another way of reducing that risk. Local does not mean it’s safer. Foodborne illness outbreaks are just as likely to occur at smaller, local farms as they are at larger, more commercialized farms. The source doesn’t matter if you’re the one who gets sick – it’s not a risk issue, it’s a magnitude issue. We often hear more about the ones at larger farms because more people are affected because of the wider distribution of their products. However, a great way to find out more about the safety and quality of local, fresh foods when shopping is to ask questions. We’ve got a great handout with some questions you can ask growers or producers at a farmers’ market or roadside stand. [Handout: Asking Questions at the Farmers’ Market]
While it may be true that preserving your own food at home can help you limit additives, there are typically few, if any, additives in commercially canned foods. It’s important to understand their functions. The most common, aside from salt, are EDTA, calcium chloride, and citric acid. EDTA is used to preserve color, while calcium chloride is a salt that is used for preserving the structure and texture of canned vegetables (it’s a stabilizer, firming, and thickening agent). Organic varieties may be less likely to contain such additives (although calcium chloride and citric acid are allowed on the National List of substances allowed in organic foods). Citric acid is used for both home and commercial canning. You may see it as an ingredient for some of the tested recipes. Unlike lemon juice or vinegar, it adds acid without adding flavor. It also works similarly to EDTA in preserving color. All of these are considered to be generally recognized as safe, or GRAS, by the FDA in quantities typically found in canned foods. The FDA looks at both safety and historical data on illnesses to regularly evaluate these ingredients to make sure they’re safe. Reading the ingredients label on commercially canned foods can help you choose varieties and brands that contain minimal or no additives.
Many people are also concerned about BPA from commercial metal cans. At present, there isn’t enough strong evidence that the amounts of BPA we get from canned foods is enough to be harmful to us. Many scientists and healthcare professionals believe that the health benefits of consuming canned foods outweigh the potential impacts from BPA exposure. However, there are certain canned brands available that are BPA-free, and many varieties are available in cartons instead of cans.
Time and cost are also factors. Canning takes time, and there are costs for the equipment and ingredients as well as the time value. The food ingredients is really what impacts the cost most, so being able to grow your own food or get it free is what will ultimately make home canning the most economical. As an example, my boss recently told me that he spent $35 on tomatoes at the farmers’ market to make only 6 quarts of marinara sauce. That’s a cost per quart of about $6 per jar of sauce. The average price of a quart of tomato sauce at the grocery store is probably about half that at $3.
Access is often related to cost and time. Many people are not able to produce the large quantities of raw foods needed to can. They may not have the time to can, let alone grow their own food to can. Many people do not have access to the equipment or facilities needed or large quantities of fresh foods to can, or they may have to travel farther distances to get to these.
We often want to help people in these situations who don’t have the access to healthy, fresh food. Unfortunately, food banks and food pantries can’t accept donations of home-canned food. The reason for this is because, unlike the commercial canning process, which is subjected to specific standards and regulated, we can’t monitor what people do in their own homes. We have no way of knowing how home-canned food was produced and that people are following safe practices, so for liability reasons food banks and pantries cannot accept it.
To summarize, home canning has its pros and cons, and it’s up to you as the consumer to decide what factors are most important to you and weigh the potential risks against the potential benefits.
Sources:
Codex General Standard for Food Additives (GSFA) Online Database (2016), p.95 (
CRF: The National Organic Program: The National List of Approved and Prohibited Substances (
GRAS Database (
Image credit: Word It Out

48. Motivations Local Economy Connection to food Personal
Business opportunity
Connection to food
Despite these potential constraints, why do many people choose to preserve food at home?
It lets us be local. We can source our food close to where we live – many of us can even grow it ourselves. There are a number of reasons why people would want to get their food locally, but that’s a whole other discussion we won’t have time for today.
Many people also believe it’s more economical. We just mentioned that cost is a factor in deciding if you want to can your own food. The truth is that canning equipment and ingredients can get expensive, and when you factor in the time cost, you may not really be saving money in the long run unless you’re growing all of the food yourself or can get it for less.
There’s also the business opportunity potential. Many people are trying to maximize on the demand for more local, preserved foods by getting into the home food preservation business and making preserved foods to sell to the public. There’s quite a few regulations involved in doing this, so if you have any questions about it, please see me after we’re done.
If you like gardening and cooking, it may be the connection to food that motivates you to preserve food at home. Watching it grow, harvesting it, preserving it, and then cooking with it and finally savoring the fruits of your labor (yes, pun intended) really encompasses that farm to fork idea many of us embrace. It’s more about the process of knowing where our food comes from and how it gets to our plates, and being a part of as many of those steps in the process as we can, that draws many of us to home food preservation.
Selling home preserved foods:
If you’re interested in selling your own home-preserved foods, visit the NC Department of Agriculture’s website on Starting a Home-Based Food Business for regulatory information.
The regulations allow for people to sell jams and jellies canned at home, but to sell acidified foods, like salsa, you must take a special training class. This class, called the Acidified Foods Processing School, is available as a two-part series through NC State University.
Images:
Basket:
Canned foods:

49. Image: http://tingerstastings. blogspot. com

50. Resources
Before I wrap up today’s talk, I want to give you some resources for canning foods at home.

51. THE Resources So Easy to Preserve, University of Georgia
(soeasytopreserve.com)
USDA Complete Guide to Home Canning
(free download on UGA site)
Ball Blue Book
(available for purchase online and in stores)
So Easy to Preserve and the USDA’s Complete Guide to Home Canning are literally THE resources. They’ve been around for years because they contain everything you need to know to can successfully.
The Ball Blue books also have helpful canning information, and we include theirs among our credible tested recipes. 51

52. Canning Websites
National Center for Home Food Preservation
NC State home food preservationhttps://foodsafety.ces.ncsu.edu/home-food-preservation/
You can also find information from these sources online through the National Center for Home Food Preservation (part of the University of Georgia) and our own NC State Food Safety website. 52

53. Selling Home Preserved Foods
Resources available online through NCDA&CS
It is okay to sell jams and jellies
Acidified foods are allowed but vendors must attend specified training
If you’re interested in selling your own home-preserved foods, visit the NC Department of Agriculture’s website on Starting a Home-Based Food Business for regulatory information.
The regulations allow for people to sell jams and jellies canned at home, but to sell acidified foods, like salsa, you must take a special training class. This class, called the Acidified Foods Processing School, is available as a two-part series through NC State University.

54. Questions?
Katrina Levine, MPH, RD, LDN NC State University
I’d now like to take some time to answer any questions you may have.
Feel free to send me an or call after this presentation if you have any other questions.
Image: and