lecture #1 and #2

1. lecture #1 and #2 beer and the brewing process

2. alcohol -What is it? a class of molecules that have an –OH group methanol- 1 carbon ethanol- 2 carbons propanol- 3 carbons butanol- 4 carbons pentanol- 5 carbons

3. alcohol -Where does it come from? fundamental metabolic processes: extracting energy from sugar glucose aerobic respiration - requires oxygen - 36 ATP per glucose molecule - low energy waste products, H2O and CO2 anaerobic respiration alcoholic fermentation lactic acid fermentation

4. alcohol -Where does it come from? anaerobic respiration = fermentation - extraction of energy from glucose without oxygen - only 2 ATP per glucose molecule - very inefficient, high energy waste products - lactic acid - ethanol

5. alcohol -Where does it come from? We’re only concerned with alcoholic fermentation - many fungi and bacteria can perform alcoholic fermentation; fairly common amongst microorganisms - Saccharomyces cerevisiae brewer’s and baker’s yeast water + sugar + yeast + time = alcoholic beverage - alcohol is a byproduct of yeast metabolism, it’s a waste product, it’s yeast poop

6. alcoholic beverages the source of sugar, the process, other ingredients, and geographic origin are used to classify types of alcoholic beverages In other words, why are there so many types of alcoholic beverages? What makes beer beer?

7. alcoholic beverages -Sugar source beer wine sake mead cider pulque masato chicha cyser birch beer grains whiskey, vodka, gin brandy, grappa grapes, fruit awamori rice honey distilled mead apples calvados, apple jack agave sap tequila manioc root ?? corn bourbon honey and apples birch sap

8. alcoholic beverages -Process beer wine sake mead cider pulque masato chicha cyser birch beer grains whiskey, vodka, gin brandy, grappa grapes, fruit awamori rice honey distilled mead apples calvados agave sap tequila manioc root ?? corn bourbon honey and apples birch sap

9. alcoholic beverages -Process the process - wines typically have nothing added to them, just juice; not cooked, but cider too - sake is made with different yeasts than beer, different process - chicha is made with different yeasts than beer, different process

10. alcoholic beverages -History geographical factors: - where each type of sugar source was first domesticated - degree of isolation - local names/traditions lead to divergence of beverages

11. alcoholic beverages today, beer is usually made with four primary ingredients: (1) water (2) malted barley (3) hops (4) yeast Modern beer also has a very particular process of production the beer we know today has only been around since the mid 1600s

12. brewing beer cultivate malt mill mash sparge boil hop fine cool oxygenate pitch ferment age fine filter package enjoy HISTORICAL DISCLAIMER

13. brewing beer -Cultivating What are grains? - Angiosperm, grasses, Poaceae, (flowering plants) - the fruit of the grass, but starchy not sugary - Hordeum vulgare,barley

14. brewing beer -Cultivating other grains used in brewing: - wheat - corn - rice - rye - oats

15. brewing beer -Malting but yeast can’t use starch to live, thus they can’t make alcohol from starch - this is not an issue in wine making, why? - a big difference in process

16. brewing beer -Malting what is starch?

17. brewing beer -Malting need to convert the starch to sugar so that the yeast can use the energy stored in the starch to make alcohol - what is fruit for? why do plants have fruit? why do grasses have grains?

18. brewing beer -Malting no living thing (or very few living things) can use starch directly to get energy - most living things need to convert starch to sugar first - yeast can’t do it - some fungus can - plants can - humans can

19. brewing beer -Malting brewers borrow the plant’s ability to convert starch to sugar by tricking them into thinking they’re growing this is malting α-amylase β-amylase also in human saliva soak sprout spread and germinate kiln

20. brewing beer -Malting malting is also where much of a beer’s character is determined - type of barley used - 2 row vs 6 row - color, protein - American - Canadian - English -Maris Otter - Scottish –Golden Promise –terroir? - German - Belgian - malting method - floor malted - machine malted - kilning fuel –peat, wood smoke

21. brewing beer -Malting kilning - temperature - length - moisture content types of malt - base malt - biscuit - Vienna - Munich - aromatic - crystal - chocolate - black patent - roasted barley

22. brewing beer -Milling need to expose the starch don’t want to pulverize the grains, need to keep the husks intact for the sparge or else big trouble –peated malt

23. brewing beer -Mashing converting starch to sugar by activating a suite of enzymes that were created by malting the grain mix milled grains with water in a mash tun water/grain ratio, temperature, water chemistry all affect how the starch is converted low temps, 140°F = lots of glucose high temps, 160°F = lots of complex sugars, dextrins

24. brewing beer -Mashing glucose 140°F 150°F + starch 160°F glucose maltose dextrin

25. brewing beer -Mashing some beers use unmalted grains in the mash such as corn, rice wheat, the big 3 use a lot of these adjuncts - how could this be a problem? how to remedy the problem?

26. brewing beer -Sparging how to separate the crushed grain from the sweet liquid, the wort, that will become beer? - straws - grain bed, husks lauter tun (usually mash tun too)

27. brewing beer -Sparging recirculation –recirculate the wort until it is clear parti gyle –do one mash, then drain all the wort off, add more hot water, do another mash, drain all the wort, continue until all sugars are gone - usually results in two or three smaller batches of beer that range from strong to medium to weak sparging –do one mash, begin to drain the wort off and as the wort level falls, add hot water, sparge water, to rinse the sugars from the grains, continue until all sugars are rinsed - usually get one big batch of beer that is one strength, weaker than first runnings of parti gyle but stronger than second runnings

28. brewing beer -Sparging What do I mean by strong and weak wort? original gravity –the density of the wort before fermentation determined by how much sugar is dissolved in the wort high gravity = lots of sugar = high density lots of sugar = potential for lots of alcohol

29. brewing beer -Boiling wort –the clear, sugary liquid that is collected during run off, also called sweet wort collected in the boil kettle or just kettle why boil? - “sterilize” wort - coagulate proteins - concentrate sugars - extract hop oils

30. brewing beer -Hopping Humulus lupulus a tall, non-woody vine that dies back to the ground every winter, perennial, Cannabaceae family, sister genus to hemp female flowers produce cones that bear lupulin glands which contain many different oils that contribute bitterness, flavor, and aroma to beer, also bacteriostatic, used to balance sweetness of malt must be boiled vigorously to extract the oils

31. brewing beer -Hopping

32. brewing beer -Hopping many different varieties, typically grouped by region of origin, American hops most distinct - England - Fuggles - East Kent Goldings - Target - Challenger - Germany - Spalt - Tettnanger - Hallertau - United States - Cascade - Simcoe - Chinook - Magnum - Czech Republic - Saaz

33. brewing beer -Hopping hops are just one type of spice others still used today - orange peel - coriander more historical - rosemary - spruce tips - myrica gale - wormwood - mints

34. brewing beer -Fining fining –the addition of material to beer or wort that aids in the clarification of the wort and beer during the boil, carrageen in Irish Moss helps pull proteins out of solution

35. brewing beer -Cooling

36. brewing beer -Oxygenating even though fermentation is an anaerobic process, we want the yeast population to be large enough and strong enough to have a healthy fermentation

37. brewing beer -Pitching pitching –the addition of yeast to the cooled wort, also called bitter wort now until very recently, 1940s and 50s in England, mixed cultures of yeast were pitched pure culture fermentation, only one type of yeast, was not adopted until 1890s in Europe, now almost universal 1/1000 of a millimeter

38. brewing beer -Yeast and fermentation fungi Ascomycota yeast Basidiomycota

39. brewing beer -Yeast and fermentation Basidomycota Ascomycota

40. brewing beer -Yeast and fermentation fermentation –the period of time from pitching to complete attenuation (also the biochemical process that makes ATP without oxygen) attenuation –the degree to which the yeast convert sugar to alcohol and CO2 original gravity –density of the bitter wort before pitching, many sugars dissolved in the wort final gravity –density of beer after fermentation is complete, depends on yeast strain, mash temps

41. brewing beer -Yeast and fermentation stages of fermentation primary fermentation -where vast majority of attenuation occurs, 3-20 days lag phase –yeast are acclimating to wort, little obvious activity, 2-24 hours aerobic phase -yeast grow very rapidly, population increases exponentially, consumes much of the sugar, much attenuation occurs here, consumes oxygen, obvious activity, 1-5 days anaerobic phase –yeast begin to ferment the sugars left in the wort, activity slows, 1-15 days

42. brewing beer -Yeast and fermentation secondary fermentation –to be covered in aging section

43. brewing beer -Yeast and fermentation Saccharomyces cerevisiae sacchar- sugar (saccharide, saccharine) myces- fungus (ancient Greek) ceres- Greek goddess of agriculture? (cereal) Saccharomyces carlbergensis Carlsberg- Danish city where lager species was first isolated

44. brewing beer -Yeast and fermentation Saccharomyces cerevisiae -ale yeast –warm fermentation, between 65-90°F (avg 70°F), typically more character than lager strains, less attenuative, short fermentation and aging, as short as 5 days from grain to glass, top fermentation

45. brewing beer -Yeast and fermentation S. uvarum (S. carlbergensis) –lager yeast –cool fermentation, between 48-55°F, typically cleaner than ale strains, more attenuative, long fermentation and aging, primary: 20 days, secondary or lagering period, at least 14 days, bottom fermentation

46. brewing beer -Yeast and fermentation many different strains within each species, 1000s of strains - in addition to alcohol and CO2, different strains contribute different flavors and aroma - Belgian strains: lots of character, fruity, clove, can be very attenuative even though they’re ale strains - English strains: lots of character, fruity, bready, not attenuative, ale strains - German strains: mostly lager strains, clean, attenuative - American strains: both ales and lager, typically clean

47. brewing beer -Yeast and fermentation

48. brewing beer -Yeast and fermentation spontaneous fermentation –no yeast is added “by hand”; Belgian lambic style beer; many different microorganisms

49. brewing beer -Aging after fermentation, beer is generally racked from one vessel to another, from the primary fermenters to the aging tanks beer is aged for a couple reasons - to complete attenuation - *for proper flavor development, yeast reabsorb certain molecules, chemical reactions occur etc.* - for the beer to clear aging also known as secondary fermentation some ales not aged at all, Upland Wheat, most aged only 1-2 weeks, very strong ales aged up to a year or more

50. brewing beer -Aging