20 Brewing Answers

Here are the answers to the quiz I posted on Tuesday.

1.) The liquid that yeast cells ferment to make beer is

a.) strike water.

b.) trub.

c.) wort.

d.) brewing liquor.

e.) my second favorite liquid. 

Strike water is the water used at mash in. Trub is the debris at the bottom of the kettle, and brewing liquor is any treated water used in brewing.

2.) Besides beer, another fermented beverage made from plants is

a.) mead.

b.) vodka.

c.) wine.

d.) kefir.

e.) never mentioned in Beer & Wine Journal.

Mead is made from honey, an animal (bee) product. Vodka is both fermented and distilled, and kefir is fermented milk — another animal product.

3.) Stale beer frequently contains elevated levels of

a.) acetaldehyde

b.) trans 2 nonenal

c.) 4 vinyl guaiacol

d.) ethyl acetate

e.) enthusiasm for getting off your butt and brewing your next batch of beer.

Acetaldehyde is a molecule produced by the oxidation of ethanol. Four vinyl guaiacol is the compound responsible for the “clove” aroma in German wheat beers and ethyl acetate is an ester that is abundant in ales. (The correct spelling of the right answer is trans 2 nonenal, not trans 2 nonenol, as it appeared in the original quiz.) 

4.) A hop stand is

a.) a mixture of spices that can replace hops when they are scarce.

b.) adding hops before the boil has started.

c.) a device that holds hops during the boil.

d.) adding lots of late hops after the boil is finished.

e.) a good start.

There is no non-hop substitute for hops. Adding hops before the boil starts is first wort hopping, and one device for holding hops during the boil is a hop spider.

5.) Which of the following is most closely associated with fermentation?

a.) glycolysis

b.) the Krebs cycle

c.) the Calvin cycle

d.) mitochondria

e.) A party in my garage when it’s finished.

The first few steps in fermentation, shared with aerobic respiration, are the glycolytic pathway. Krebs cycle is part of aerobic respiration. The Calvin cycle is part of photosynthesis, and mitochondria o are the organelles in which aerobic respiration takes place.

6.) In the boil, roughly 25–35% of the alpha acids in the bittering hops are converted to

a.) alpha acetolactate

b.) iso alpha acids

c.) beta acids

d.) myrcene

e.) something else.

Alpha acetolactate is excreted by yeast during fermentation and oxidized to diacetyl. Beta acids are similar compounds to alpha acids, but heating does not convert one into the other, and myrcene is an essential oil in hops.

7.) Barley is

a.) a cereal grain, in the same botanical family as buckwheat.

b.) a non-cereal grass, in the same botanical family as rushes.

c.) a cereal grain, in the same botanical family as wheat.

d.) a fungus in the Division Ascomycota, related to Penicillium.

e.) in my heart, it’s in my soul. It’ll be my breath should I grow old.

As was warned, some of the answers were not just wrong, but doubly wrong. For instance, buckwheat is not a cereal. It’s not even a grass. Rushes are a grass, but not a cereal, like wheat or barley. And barley is obviously a plant, not a fungus.

8.) The products of alcoholic fermentation are

a.) ethanol, carbon dioxide, and heat.

b.) methanol, oxygen, and heat.

c.) ethanol, carbon dioxide, and gamma rays.

d.) isopropyl alcohol, air, and infrared light

e.) in my bloodstream.

The other answers are just combinations of similar things that aren’t produced together by any process I know of. In nay case, gamma rays aren’t emitted by ordinary chemical reactions. They come from radioactive atoms.

9.) The most abundant sugar in wort is

a.) glucose.

b.) maltose.

c.) amylose.

d.) fructose.

e.) about to meet my yeast.

Glucose and fructose are two simple sugars (monsaccharides) and amylose is a type of starch.

10.) Wort boils at

a.) 315 °F (157 °C).

b.) 215 °F (102 °C).

c.) 212 °F (100 °C).

d.) 100 °F (38 °C).

e.) my command.

Wort contains dissolved solids that elevate it’s boiling temperature above that of water, 212 °F (100 °C). And of course, elevation above sea level and barometric pressure will influence the boiling temperature as well.

11.) The chemical formula for ethanol is

a.) H2O + CO2

b.) C2H5OH

c.) C6H12O6

d.) 6.02 X 1023

e.) known and beloved by chemists all over the world.

The first answer is water and carbon dioxide, the thrid answer is the formula for the sugar glucose and “d” is not a chemical formula at all, but a number, Avagadro’s number, the number of atoms in a mole.

12.) Hops are most closely related to which of the following?

a.) hackberries, also called nettle trees

b.) wisteria, a vining flower

c.) hemlock, a type of conifer

d.) lupine, a flowering vine in the legume family

e.) To be revealed on Maury later. 

Hops are in the Cannabaceae family, along with cannabis — the relative that’s always mentioned — and hackberries. Wisteria and lupine are both vining flowers, like hops, but from another family. Hemlock, as a conifer does not flower — and it’s cones and the cones on hop plants are not related anatomical structures although they bear the same name.

13.) In the mash, the enzymes that degrade starch by hydrolysis are

a.) alpha amylase, beta amylase, and limit dextrinase

b.) alpha amylase and beta amylase

c.) The starch degrading enzymes work by pyrolysis, not hydrolysis

d.) beta amylase

e.) in my heart, they’re in my soul. They’ll be my breath should I grow old.

The answer says it all, alpha amylase, beta amylase, and limit dextrinase hydrolyse starch in the mash. Pyrolysis is breaking down a compound by heat, but mash temperatures are not high enough to break down starch due to heat.

14.) Another term for mashing in is

a.) doughing in

b.) knocking out

c.) casting out

d.) ringing Jerry 

e.) not needed since we already have the term “mashing in.”

Knock out is the end of the boil and cast out wort is the wort (minus the trub) that leaves the kettle after the boil. Ringing Jerry is just gibberish.

15.) Kräusening is

a.) adding vigorously fermenting lager beer to a lager fermentation that is finishing.

b.) mixing a small amount of trub with the wort being transferred to the kettle.

c.) rousing the yeast by rolling a barrel fermented beer around the brewery.

d.) carbonating the beer by injecting CO2 in it via a sintered stone.

e.) a great word. One of the best. I hear a lot of good things about kräusening these days, and I wish them all the best.

“B” is a thing, but not one that has a name (as far as I know). Small amounts of trub may help in fermentation. “C” is just one way of rousing yeast and “D” is a common way to carbonate beer, but it has nothing to do with kräusening.

16.) A mash in which a portion of the grist is removed and boiled, then returned to the main mash

a.) is a vorlauf.

b.) is a decoction mash.

c.) used to be known as the Crabtree Effect.

d.) will become a hopscotch mash, after the mash out. 

e.) makes for a long, tiring brew day.

Recirculating the wort is also known as the vorlauf. The Crabtree effect is the effect high sugar concentrations have on brewers yeast under aerobic conditions. (It causes them to ferment, rather than respire.) A hopscotch mash is made up, although it sounds a little like a Hochkurz mash (a short, high temperature mash program).

17.) Malt extract is made by

a.) starch pyrolysis under pressure.

b.) starch synthesis on a cellulose matrix.

c.) light driven reactions combining carbon dioxide and water in an organelle.

d.) evaporating water from wort in a vacuum.

e.) the fine people at Briess Malting, who once bought an ad on our site.

“A” and “B” are just chemistry words strung together. “C” is a vague description of photosynthesis.

18.) Yeast is

a.) a bacteria, related to Lactobaccilus

b.) a protist, related to red algae

c.) a plant, related to Irish moss

d.) a fungus, related to truffles

e.) the word. It’s got groove. It’s got meaning. Yeast is the time, is the place, is the motion. And yeast is the way we are feeling.

Yeast is a fungus related to truffles. “C” is another doubly wrong answer. Irish moss is a seaweed (a protist), not an actual moss (a type of plant). The other answers are just wrong.

19.) The steps in malting are

a.) amineation and phosphorylation, followed by adiabatic de-amineation

b.) the soft spile, the shive, and the hard spile.

c.) wetting, saccharification, and denaturing the enzymes.

d.) steeping, germination, drying, and kilning.

e.) totally worth it, from the standpoint of friability.

“C” is kinda, sorta an explanation of mashing. Spiles are devices pounded into the shive bung of a cask and the first answer is just a hodgepodge of chemistry terms.

20.) Which of the following is NOT an essential oil commonly found in hops?

a.) caryophyllene

b.) farnesene

c.) geraniol

d.) Answers a, b, and c are all common hop oils.

e.) 10W-30

“D” is correct. However, although geraniol is listed among the essential oils on hop analysis reports, it’s not actually an oil. It’s an aromatic compound, like other essential oils, but it’s soluble in water.


  1. Damn it! Missed one… pesky glycolysis! 😉

  2. I live at sea level and wort boils at 100C where I live. It might boil a smidge above 100 because of dissolved solids but it definitely isn’t 2C above. Did you mean to put 100.2C?

  3. Rômulo Rocha says

    The number 20 asked witch one was NOT a essencial oil, here in Brazil 10w-30 is a car oil and not a hop oil.
    Asked doctor google and could not find any reference to 10w-30 as a hop oil, wha am i missing?

  4. Re: Question #2
    Technically Mead is also made from a plant.
    Bees collect the pollen (Which has plant origins. Basically play sperm). Which makes honey. Which is fermented into mead.

  5. I’ve never seen a lupine vine. Do they grow this way in Texas? Legume, yes, but vine?

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