Brewer Brewing Process & Techniques Flashcards

What is the purpose of krausening in lager production?

Answer: Adding a small quantity of actively fermenting wort to a finished beer to promote natural carbonation and condition it

Krausening adds 10–15% actively fermenting young beer (kräusen) to condition a finished lager, naturally carbonate it, and absorb off-flavor compounds via yeast activity.

In the context of dry hopping, what is 'hop creep' and why is it a concern?

Answer: Refermentation caused by hop-derived amyloglucosidase enzymes breaking down residual dextrins into fermentable sugars

Hop creep occurs when amyloglucosidase enzymes present in dry hops break down unfermentable dextrins into glucose, causing unintended refermentation and over-carbonation.

What is the recommended dissolved oxygen (DO) level in packaged beer to minimize staling?

Answer: Less than 50 ppb (0.05 ppm)

World-class lager breweries target less than 50 ppb (0.05 ppm) dissolved oxygen at packaging to minimize oxidation reactions that cause staling.

What is the chemical compound primarily responsible for a 'skunk' or 'lightstruck' off-flavor in beer?

Answer: 3-Methyl-2-butene-1-thiol (MBT) formed when UV/visible light strikes isomerized hop compounds

3-Methyl-2-butene-1-thiol (MBT) is produced when light photodegrades isomerized alpha acids (iso-alpha acids), creating the characteristic skunk-like off-flavor.

Which filtration method uses a rotating drum coated with diatomaceous earth to continuously filter beer?

Answer: Rotary vacuum precoat filtration (RVPF)

Rotary vacuum precoat filtration uses a rotating drum precoated with diatomaceous earth, continuously shaving off the spent cake to expose fresh filter medium.

What is the primary reason brewers measure titratable acidity (TA) in addition to pH?

Answer: TA measures the total buffering capacity and acid concentration, while pH only measures hydrogen ion activity

Titratable acidity measures total acid concentration and buffering capacity, providing a more complete picture of mash or wort acidity than pH alone.

What is the function of a heat exchanger grant in a modern brewing system?

Answer: It is a collection vessel between the lauter tun and wort pump that allows flow rate monitoring and air-free transfer

A grant is an open or sight-glass vessel that collects runoff from the lauter tun, allowing the brewer to monitor clarity and control flow rate without creating a vacuum on the grain bed.