Food And Fermentation Part 2 PDF

Food And Fermentation Part 2 SC/NATS1560 3.0 Understanding Food Dr. Angela Cope: [email protected] ©2024 1  Learning Objectives To describe alcoholic fermentation,...

Food And Fermentation Part 2 SC/NATS1560 3.0 Understanding Food Dr. Angela Cope: [email protected] ©2024 1  Learning Objectives To describe alcoholic fermentation, define “wild yeasts”, and name the microorganism most commonly used for alcoholic fermentation To describe the most common drinks and foods produced by alcoholic fermentation, their raw ingredients, and their processing Wine Beer Bread Dr. Angela Cope: [email protected] ©2024 2  Alcoholic fermentation: yeasts convert sugars into ethyl alcohol and carbon dioxide Ethyl alcohol, or ethanol (“drinking alcohol”*) − psychoactive substance, narcotic − in moderate amounts, it causes mild inebriation − in larger amounts, intoxication and addiction − antiseptic, it kills harmful microbes “Wild yeasts”, or natural starters Saccharomyces cerevisiae Alcoholic Fermentation Dr. Angela Cope: [email protected] ©2024 3  Wine I Made mostly from grapes of Vitis vinifera Over 1300 varieties e.g., cabernet sauvignon, merlot, pinot noir, syrah, grenache, sangiovese, chardonnay, riesling, sauvignon blanc, sémillon, chenin blanc, pinot grigio, etc. Terroir: place of origin, gives distinctive character to the wine Alcohol content: 8%-14% ABV Wines are made also from other fruit, e.g. cherries, dates, apples (cider), pears (perry) Dr. Angela Cope: [email protected] ©2024 4 Vinification (wine-making): Grapes are crushed into must Wine II Wild yeasts or inoculated Saccharomyces cerevisiae convert sugars into CO2, ethanol, and aromatic molecules Skins are steeped in to give colour and stronger flavours Wine is racked to eliminate the dregs (dead yeasts and skins), filtered, and fined Wine is aged if in oak casks, contact with wood adds complexity to the flavour finest wines, up to 30-40 years Dr. Angela Cope: [email protected] ©2024 5  Test Review What is the most used microorganism for alcoholic fermentation? A. Leptospira interrogans B. Saccharomyces cerevisiae C. Saccharomyces exiguus D. Biglius fermentatuus Dr. Angela Cope: [email protected] ©2024 6  Test Review What contributes to the distinctive character of a wine? A. Terroir B. Steeping of grape skins C. Aging in casks D. All of the above Dr. Angela Cope: [email protected] ©2024 7  From grains: barley, wheat, oats, rice, corn Grains are turned into malt by sprouting, then kilned and ground Amylase enzymes convert starch into sugars Hops added to the wort for flavour Yeast convert sugars into CO2+alcohol Making Beer Alcohol content, 4-5% (up to 10%) Ale: warm brewing (21-25 °C), top fermentation with Saccharomyces cerevisiae Lager: bottom fermentation (6-8 °C), cold brewing with Saccharomyces uvarum Dr. Angela Cope: [email protected] ©2024 8 Brewing Beer Malting the grains Kilning and grounding the malt Mashing the malt Adding hops and boiling the wort Adding yeast and fermenting Conditioning: re-fermenting, fining & centrifuging Dr. Angela Cope: [email protected] ©2024 9  Test Review How is lager different from ale? A. Bottom vs top fermentation B. Cold vs warm brewing C. Saccharomyces uvarum vs Saccharomyces cerevisiae D. All of the above Dr. Angela Cope: [email protected] ©2024 10  Flour: milled grains Hard wheat: high protein Bread content (glutenin, gliadin) Amylase breaks down some of the starch into sugars Flour + water = dough Glutenin + gliadin (in water) = gluten Kneading allows gluten to form an elastic mass Leavening by fermentation: yeast (wild or Saccharomyces cerevisiae) turns sugars into CO2 and alcohol gas bubbles make dough rise Dr. Angela Cope: [email protected] ©2024 11 (Butt) Bread Heat solidifies stretched dough Sourdough bread uses a starter containing “wild yeasts” (yeasts and lactic acid bacteria) Baking completes and then stops the fermentation Surface water evaporation and Maillard reactions form crust and crumb Dr. Angela Cope: [email protected] ©2024 12  Unfermented Breads Unleavened flatbreads: matzo or matzah, lavash, rotis, chapatis, tortillas (from corn flour), and others Quick breads: leavened by CO2- producing chemical reactions without fermentation e.g., cakes, scones, cookies, pastries, biscuits, etc. chemical leaveners: baking powder, Dr. Angela Cope: [email protected] ©2024 baking soda, ammonia salts 13  Test Review What is the difference between sourdough bread and non-sourdough bread? A. Sourdough bread uses a starter containing “wild yeasts” (yeasts and lactic acid bacteria) B. Sourdough uses vinegar as a preservative C. Sourdough is unleavened D. You can only make “Butt bread” with non- sourdough Dr. Angela Cope: [email protected] ©2024 14  Home Review What happens when milk curdles, and how does it apply to cheese? How does mold affect cheese? Give three examples of each of the two main kinds of fermentation What is malt and how is it used in beer brewing? What are the main differences between wine making and beer brewing? Dr. Angela Cope: [email protected] ©2024 15