1. How it is brewed and how to brew your own

2. The four ingredients in beer Malt is partially germinated barley. Before being used to brew beer it must undergo a process called mashing. Malt supplies the sugars that the yeast metabolize to make alcohols, carbon dioxide, and flavor compounds. Hops are flowers that impart flavor, aroma, and bitterness. Hops also help preserve the beer against spoilage. Yeast are eukaryotic single-cell organisms. In brewing they metabolize sugars from the malt to produce alcohols. There are hundreds of cultured strains of beer yeast that yield different flavors and bodies to the beer. Water plays a supporting role in every step of brewing. Different mineral content in the water used will affect amino acid availability for the yeast, conversion of starch into fermentable sugar, and other reactions that prevent off-flavors. 1. Malt 2. Hops 3. Yeast 4. Water

3. More about malt Germination begins enzymatic activity and enzyme development Degree of germination determines starch and enzyme availability

4. Do the mash! Malts are added to water to extract proteins and starches Enzymes activated at specific temperatures degrade proteins and starches

5. Do the mash!

6. What happens with the hops Boiling hops releases and dissolves bitter resins Hops can contribute strong floral and fruit flavors Hopping during fermentation gives yet another character

7. Boiling your wort Boiling caramelizes sugars, dissolves hop resins, and denatures proteins The boil is a prime opportunity for adding flavors Boiling kills bacteria in the wort, but also depletes oxygen

8. Yeast: the beasties behind the brew Ale yeasts are top- fermenting while lager yeasts bottom-ferment Yeast ferment maltose, glucose, fructose, etc. but not dextrins, lactose, or invert sugar Contribute alcohol and CO2, as well as esters and diacetyl Yeast have to compete with bacteria like lactobacilius for dominance in the wort Origins of beer styles are linked to wild yeasts in that region

9. Yeast: the beasties behind the brew Yeast Stir Plate

10. Fermentation & the ugly krausen Cooled wort is moved to a fermenter and aerated, and yeast is pitched Fermenter is sealed off from oxygen Violent foaming fermentation called krausen rises out of wort (and sometimes the fermenter)

11. Fermentation & the ugly krausen

12. Patience: a difficult virtue After primary fermentation (1 to 3 weeks), additional conditioning occurs Secondary fermentation (2 weeks to months) Barrel aging (months) Bottling conditioning (3 weeks to months) Secondary fermentation allows for: Dry hopping Adding fruit, spices, wood, etc. Bottle conditioning involves: Carbonation Conditioning

13. Resources for learning more How To Brew – John Palmer (free online book) The Complete Joy of Homebrewing – Charlie Papazian www.homebrewtalk.com Brooklyn Homebrew (in Park Slope)