Unit 0: A Primer on Brewing Chemistry Flashcards
“Big to Small” - the Soul of Beer - What do we mean by this regarding many brewing processes?
A large portion of the brewing process focuses on liberating proteins and carbohydrates from barley and breaking them down to form the nutrients needed by yeast to produce alcohol and other attributes of beer.
How do carbohydrates get broken down in the brewing process?
Long complex starch molecules found in raw barley must be chopped into the smaller individual sugars that yeast can digest. In malting and mashing, brewers liberate starch from the storage structures inside the barley kernal and generate the enzymes needed to further break the starch down into the simpler sugars that can be acted upon by yeast.
How do proteins get broken down in the brewing process?
Malting and mashing break down proteins, another group of large, complex molecules.
Some proteins get broken down very finely into free amino acids, the basic building blocks of protein, but this isn’t completely desirable.
Larger proteins contribute to foam and mouthfeel.
So, it’s desirable to strike a balance.
What are Mailliard reactions?
The Maillard reaction is responsible for many colors and flavors in foods, such as the browning of various meats when seared or grilled, and the browning and umami taste in fried onions, and coffee roasting. It contributes to the darkened crust of baked goods, the golden-brown color of French fries and other crisps, the browning of malted barley as found in malt whiskey and beer, and the color and taste of dried and condensed milk, dulce de leche, toffee, black garlic, chocolate, toasted marshmallows, and roasted peanuts.
It’s an organic chemical reaction in which reducing sugars react with amino acids to form a complex mixture of compounds. This reaction is responsible for the characteristic flavor and aroma of browned food. The Maillard reaction is named after the French chemist Louis Camille Maillard.
What do we get from hop oils?
Oils are extracted from hops in the boil and later in dry hopping and contribute greatly to the flavor and aroma of beer
What do we get from hop alpha acids?
The hop alpha acids produce hop bitterness. They become iso-alpha acids during the boil, and need the longest time in the boil so they are added first.
What do we get from tannins and polyphenols?
Mostly off flavors and they can come from both malt and hops. We don’t want to harvest those in excess.
Flavors from fermentation and maturation: esters
gives fruity flavors
Flavors from fermentation and maturation: phenols
gives spicy flavors
Flavors from fermentation and maturation: acids
gives sourness
Can yeast add specific flavors to beer?
Yes, each strain of yeast delivers specific and unique flavors that can make dramatic differences in the finished beer
What are two variables brews can use in fermentation?
Temperature and time
What variables can lead to different flavors employed during maturation?
Maturation begins as a simple extension of fermentation and can last from a few weeks to several years and
–May involve additional organisms such as Brettanomyces, other wild yeasts, bacterias, etc.
–May involve aging in oak or other wood barrels, often used for liquors
–May involve additional fermentable sugars
–May involve additives such as fruit or fruit juices, coffee, molasses, or other flavorings
