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

Overview History of Canning Canning Safely Canning Processes Health and Nutrition Questions

Food Preservation Fruits Vegetables Meats Poultry Eggs

12,000 francs, in 1809 when he submitted his method of “food in glass bottles.” Nicolas Appert

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.

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).

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

Clostridium botulinum 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 o oxygen-free environment o low-acid food o temperature between 40ºF to 120ºF o relatively high moisture

2012 CDC surveillance 160 cases 25 cases foodborne 12 were linked to 2 pruno outbreaks

Clostridium botulinum Ashe County, North Carolina Only one bite of improperly-canned carrots led to 11 weeks in the hospital for one woman Clostridium botulinum Ashe County, North Carolina Only one bite of improperly-canned carrots led to 11 weeks in the hospital for one woman

Clostridium botulinum Lancaster, Ohio One death and 24 illnesses Linked to a church potluck Canned potatoes in potato salad

Pickled beets, that weren’t actually pickled linked to 3 Oregon illnesses in 2012

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

Process Food Properly Follow a credible recipe exactly o No substitutions! o The following slows heat penetration: Extra sugar or fat Oversized food pieces Added thickeners

Process Food Properly Processing times o Lots of factors affect o Heat-up and cool-down times in pressure canners are counted toward sterilizing value of the process. Never rush them. Use the right equipment! o Pressure canner – low acid foods

Unsafe Canning Methods Open Kettle Oven Canning Dishwasher Addition of Aspirin Steam Canners* Microwave Oven Canners *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.

Canning Basics

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.

Two Methods of Canning Boiling Water Canning High-acid foods Acid kills C. botulinum spores Heats to 212°F – destroys spoilage organisms and some foodborne pathogen Pressure Canning Low-acid foods (and some high-acid foods) Heats to 240°F to kill C. botulinum spores (not enough acid)

Food Acidity High (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)

Boiling Water Bath Used for high-acid foods and acidified foods

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.

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.

Pressure Canning Used for low-acid foods

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.

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. Using a Pressure Canner

Testing for Seals Listen for “pop” Lid curved inward, won’t move when pressed Clear ringing sound when tapped

Canning Jars and Lids Jars o Approved canning jars o Clean, sanitized if <10 min processing time o Free of nicks, cracks, rough edges Lids o 2-piece o Cannot reuse flat part o Follow manufacturer’s directions

Preparing and Packing Food

Raw vs. Hot Pack Raw pack o For food that looses shape when cooked o Put raw foods in jars, pour hot water over o Put in warm or hot water Hot pack o For most foods o Food cooked before packing o Put in simmering water

Headspace Space between the inside of the lid and the top of the food or its liquid. Check recipe for directions Usually: o 1/4” for jellies o 1/2” for high-acid foods, such as fruits, tomatoes, and pickles o 1” to 1-1/4” for low-acid foods

Before Sealing Jars Remove air bubbles. Re-adjust headspace if necessary. Wipe jar rims. Adjust two-piece lids, fingertip-tight.

Jams and Jellies

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

Types of Jams and Jellies Jam Jelly Marmalade Preserves Conserves Butter

Essential Ingredients Fruit Pectin Acid Sugar

Fruit Provides flavor Furnishes pectin and acid for gelling 1 pound fruit = 1 cup juice Use top quality fruit

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 in Fruits HighLow Apricots Blueberries Cherries Peaches Pineapple Rhubarb Strawberries Tart Apples Concord Grapes Sour Blackberries Cranberries Currants Gooseberries Quinces Sour Plums

Commercial Pectin Liquid or powdered Purchase fresh each year Advantages o More jelly produced from the fruit o Better color o Less chance of failure o Shorter cooking time

Acid Needed for gel formation. Under-ripe fruits have more acid. Commercial pectin contains some acid.

Sugar Contributes to flavor. Helps in gel formation. Serves as preserving agent.

Sugar Substitutes Sugar subs o Light Corn Syrup o Honey May cause flavor and structure changes Use tested recipes Do NOT reduce sugar amount

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

Health and Nutrition

Nutrition Antioxidants Phytochemical s “Good” bacteria (probiotics) Sugar Salt Vitamin loss during cooking PROSCONS

Weighing the Pros and Cons

Local Economy o Personal o Business opportunity Connection to food Motivations

Resources

So Easy to Preserve, University of Georgia o (soeasytopreserve.com) USDA Complete Guide to Home Canning o (free download on UGA site) Ball Blue Book o (available for purchase online and in stores) THE Resources

Canning Websites National Center for Home Food Preservation NC State home food preservationhttps://foodsafety.ces.ncsu.edu/h ome-food-preservation/ ome-food-preservation/

Questions? Katrina Levine, MPH, RD, LDN NC State University

NCDA&CS resources on this o It is okay to sell jams and jellies Acidified foods are allowed but vendors must attend specified training o manufacturing-school/ Selling Home Preserved Foods