Fermentation & General Flashcards
What is wort?
A sugar-rich liquid made from steeping malted grain in water.
Under the Bavarian Purity Law (1516), what are the three ingredients in beer?
Barley, Hops, Water (yeast was not yet understood to be part of fermentation)
What is Reinheitsgebot?
The Bavarian Purity Law
What is the preferred choice of grain for brewing (barring speciality styles)?
Barley
What is amylase?
An enzyme that converts starchy carbohydrates into the fermentable sugars maltose and dextrin.
How does the act of drying the malted barley impact the style of beer?
The length and degree of roasting will affect the character of the malt - heavy roasting for porters, light toasting for pale ales, etc.
What is green malt?
Germinated barley before drying
What is grist?
Ground malted barley (between drying and mashing)
What process leads to wort?
Mashing: the combination of grist and hot water to extract sugars
What is sparging?
Rinsing the spent mash with fresh water to extract more sugar and flavor - will extract more bitterness as well.
What is a copper?
A brew kettle: the vessel for boiling the wort
How long is the wort boiled? Why?
At least one hour, to stabilize and sterilize, darken the color, and evaporate excess water.
What is added to the copper before boiling?
Hops
How do hops behave through the boiling process?
They become more bitter as they boil longer, and lose aromas.
What is a hopback chamber?
A sealed chamber between the copper and the chiller - hops are added, the hot wort is run through, and then immediately chilled, preserving the volatile hop aromas.
Contains a filter at one end to strain out the hop petals.
What is the latin for top fermenting yeast?
Saccharomyces cerevisiae
What is the latin for bottom fermenting yeast?
Saccharomyces pastorianus
What is the former name for Saccharomyces pastorianus?
Saccharomyces carlsbergensis
Is bottled beer pasteurized?
Yes, usually.
Is draught beer pasturized?
Yes usually, with the exception of cask ales.
What are bottle-conditioned beers?
Unfiltered beers that undergo partial fermentation in bottle.
What is Alcohol by Weight?
Amount of alcohol in beer meansured in term of the % weight of alcohol per volume. Approximately 20% less than ABV.
Why is a wooden bung required for “real” beer?
It allows the pressure of fermentation to be relieved, especially if the cask is made of metal.
What is Chill proof?
Cold stabilization.
What is Conditioning?
Period of maturation intended to impart “condition” (natural carbonation).
Warm conditioning develops complexity of flavors
Cold conditioning imparts a clean, round taste
What is a Conditioning Tank?
A vessel in which beer is placed after primary fermentation where the beer matures, clarifies, and is naturally carbonated through secondary fermentation.
Also called Bright Beer Tank, Serving Tank, or Secondary Tank.
Beer conditioned in cask (cask-conditioning) has lighter carbonation.
What is dextrin?
The unfermentable carbohydrate produced by the enzymes in barley. It gives flavor, body, and mouthfeel.
Lower temperatures produce more deztrin and less sugar; higher temperatures produce more sugars and less dextrin.
What is Draft?
The process of dispensing beer from a bright tank, cask, or keg, by hand pump, pressure from an air pump, or injected carbon dioxide intserted into the beer container prior to sealing.
What is Krausening?
The addition of a small proportion of partly fermented wort to a brew during lagering; stimulates secondary fermentation and imparts a crisp, spritzy character.
What is Lagering?
“Storage.” Maturation for several weeks or months at cold temperatures (close to 0ºC) to settle residual yeast, impart carbonation, and make for clean, round, flavors.
What is Lauter?
To run the wort from the mash tun, from the German “to clarify.” A lauter tun is a separate vessel to do this job, using a system of sharp rakes to achieve an intense extraction of malt sugars.
What does Lightstruck indicate?
A skunklike smell from exposure to light (happens in bottle from improper storage).
To what temperature is beer heated during pasteurization?
140-174ºF
What is maltose?
A water soluble, fermentable sugar in malted barley.
What is Decoction?
An exhaustive system of mashing in which portions of the wort are removed, heated, and returned to the original vessel.
What is Attenuation?
The extent to which yeast consumes fermentable sugars in the beer.
What are the four noble hops?
What characteristics do they share?
Hallertauer Mittelfrüh (Bavaria, SE Germany)
Tettnang (Swabia, near Bodensee)
Spalt (Bavaria, North of Hallertau)
Saaz (Czech)
All are highly aromatic but relatively low in bitterness.
Name three malts
Crystal
Vienna
Munich
Black
What is “attenuation”?
In brewing, attenuation refers to the conversion of sugars into alcohol and carbon dioxide by the fermentation process; the greater the attenuation, the more sugar has been converted into alcohol. A more attenuated beer is drier and more alcoholic than a less attenuated beer made from the same wort.
How much sugar the yeast eats
