Beer: Fermentation Methods Flashcards
What must happen before fermentation can commence?
Starch must be converted to sugar.
What are the two most important aspects of the brewing process?
- The brewer must first derive the wort, a sugar-rich liquid, from malted grain.
- Then the brewer must ferment the wort.
What are the ingredients required for the brewing process?
Typically, the raw ingredients required for this process are water, yeast, hops, and a starch source.
Why are hops important?
Hops, the dried flower clusters that provide flavor and bitterness to beer, have both preservative and antiseptic qualities that inhibit bacterial growth.
What is the 1561 BAvarian Purity Law?
(Reinheitsgebot), which codified the three ingredients authorized for beer production as barley, hops, and water. The action of yeast in fermentation was at the time undiscovered, and wheat, a component of Hefe-Weizen and white beer styles, was reserved for the production of bread.
What is the first step in the modern brewing process?
The first step is to create the malted barley, or malt. Barley—the cereal grain of choice for most beers—is steeped in water for approximately two days to promote germination of the grain.
What happens after the barley begins to germinate?
Once the grain begins to germinate, or sprout, it is transferred to compartments with controlled temperature and moisture levels. As the sprout grows to nearly an inch in length, the enzyme amylase is produced.
What does the enzyme amylase do?
Amylase converts the starchy carbohydrates of the grain into the fermentable sugars maltose and dextrin.
The sprout has now been converted to “green malt” What is the next step?
This “green malt” is then roasted with hot air in a kiln to suppress further growth. The style of beer desired will determine the length and degree of roasting. Highly roasted black malts, for example, are used for porter-style beers, whereas pale malt, dried at low temperatures and very light in color, is used for pale ales.
After the grain has been malted to the desired level what needs to happen next?
The malt is ground, or cracked, in a mill to produce grist. The grist is combined with hot water in a mash tun. The mashing process lasts one to two hours, converting and extracting sugar from the malt, and results in the wort, which is rich in flavor, sugar, and color.
Once the wart liquid has been made what is the next step?
The wort liquid is drawn off the grains and filtered into the brew kettle, or copper. Additional sugar and flavor can be extracted from the spent grains by sparging—rinsing with fresh water—although this may lead to unwanted bitterness in the finished brew.
What is Sparge?
Additional sugar and flavor can be extracted from the spent grains by sparging—rinsing with fresh water—although this may lead to unwanted bitterness in the finished brew.
What is done with the Sparge?
The sparge is combined with the wort in the copper, and hops are added.
What happens once the wort, sparge and hops have been combined?
The wort is then brought to a sustained, roiling boil for at least one hour. Boiling the wort stabilizes and sterilizes the brew, darkens the color, and causes excess water to evaporate.
What happens to the hops as the wort is boiling?
Hops contribute more bitterness the longer they boil, but they also lose aroma in the process.
