Certified Cicerone cheat sheet

Draught restriction: 3/16 in. ID vinyl tubing ≈ 3 psi/ft; 1/4 in. ID ≈ 1 psi/ft; total system restriction must equal applied pressure for a balanced pour.

Carbonation reference: ~2.5 volumes CO2 at 38°F requires about 12 psi; each additional volume adds roughly 5 psi at that temperature.

Elevation adjustment: required serving pressure drops roughly 0.5 psi per 1000 ft above sea level because atmospheric pressure is lower.

Nitro dispense uses a 70/30 N2/CO2 blend plus a restrictor plate in the faucet, yielding ~1.2-1.5 volumes CO2, cascading bubbles, and a creamy head.

Draught lines are cleaned every two weeks; biofilm and beerstone cause off-flavors, fobbing, and slow or foamy pours.

Lightstruck flavor: riboflavin plus visible or UV light converts iso-alpha acids to 3-methyl-2-butene-1-thiol (skunky); brown glass and dark storage reduce risk.

Storage rule: cold, dark, upright, and low-oxygen; warmth and oxygen accelerate staling, and hop aroma fades fastest.

Beer-clean glass test: a clean glass wets evenly and laces; salt or sugar sprinkled inside reveals residue rings that nucleate CO2 and kill head retention.

Serving temperature ranges: most lagers 38-45°F, most ales 40-50°F, cask ale 50-55°F; colder temperatures suppress aroma and perceived sweetness.

German Pilsner: 4.4-5.2% ABV, 22-40 IBU, pale straw, crisp dry finish with Noble hop aroma and sulfate-forward bitterness.

Hefeweizen: 4.5-5.5% ABV, low bitterness, yeast-driven banana (isoamyl acetate) and clove (4-vinyl guaiacol), cloudy and highly carbonated.

American IPA: roughly 5.5-7.5% ABV and 40-70 IBU, citrus/pine/resin hop aroma, dry finish, gold to pale amber.

Dry Irish Stout: 4.0-4.5% ABV, black, roasted barley coffee character with light astringency, about 30-40 IBU, often nitro-poured.

Berliner Weisse: 2.8-3.8% ABV, sharply lactic-sour wheat ale, very low bitterness, high carbonation, often served with syrup.

Doppelbock: 7-10% ABV, dark amber to brown, intense malt sweetness, low bitterness; traditional names end in "-ator".

Saison: 5-8% ABV, highly attenuated and dry, peppery-fruity yeast, high carbonation; historic farmhouse ale of Wallonia.

Belgian Witbier: 4.5-5.5% ABV, unmalted wheat base, coriander and orange peel, hazy pale, low bitterness, soft finish.

Diacetyl (butter, butterscotch, popcorn) comes from incomplete fermentation or Pediococcus; a warm rest lets active yeast reabsorb it.

DMS (cooked corn, cabbage) derives from S-methyl methionine in malt; a vigorous 60-90 minute boil drives it off.

Acetaldehyde (green apple, grassy) is a fermentation intermediate; cold conditioning and avoiding post-fermentation oxygen reduce it.

Trans-2-nonenal produces cardboard and papery notes; warm storage and oxygen pickup accelerate its formation during aging.

3-MBT is the lightstruck compound responsible for skunky aroma; brown glass and dark storage are the practical controls.

Chlorophenols (band-aid, plastic, medicinal) form when chlorine or chloramine in water or sanitizer reacts with yeast-derived phenols.

Perceived bitterness is heightened by high carbonation and low residual sweetness; malt sweetness and very cold serving temperature suppress it.

BU:GU ratio = IBU divided by gravity points (OG minus 1, times 1000): about 0.5 is balanced, above 0.8 is hop-forward, below 0.4 is malt-forward.

Mash rests: beta-amylase 140-150°F yields more fermentable sugar and a drier beer; alpha-amylase 158-162°F yields dextrins and fuller body.

Mash-out near 168°F denatures enzymes, halting conversion, and lowers wort viscosity so lautering runs freely.

Water chemistry: sulfate accentuates hop bitterness; chloride accentuates malt sweetness; high sulfate:chloride ratios suit IPA, low ratios suit malt-forward lagers.

Boiling 60-90 minutes isomerizes alpha acids into iso-alpha acids; utilization rises with boil time and falls as wort gravity rises.

Ale yeast (Saccharomyces cerevisiae) works at 60-68°F and top-crops; lager yeast (S. pastorianus) works at 48-55°F, then lagers near 32-40°F.

Apparent attenuation % = (OG - FG) / OG × 100; typical values run 70-80%, higher for dry styles such as saison and brut IPA.

Specialty malts: crystal adds caramel sweetness and body, roasted barley adds coffee and astringency, Munich adds bread crust depth.

Sparge water above about 170°F extracts husk tannins, adding astringency; dry hopping adds aroma only, since no isomerization occurs at fermentation temperature.

Match intensity first: delicate dishes pair with light lagers, witbier, or pilsner; bold braised or grilled dishes pair with doppelbock, stout, or barleywine.

Carbonation and acidity cut fat and cleanse the palate, which is why crisp pilsner works with fried foods.

Hop bitterness contrasts well with fat and salt but clashes with umami-rich foods such as aged cheese, mushrooms, and soy.

Malt sweetness balances chili heat and vinegar acidity better than high bitterness does; strong bitter beer amplifies burn.

Sour beers (lambic, gueuze, gose, Berliner Weisse) cut through rich, fatty, creamy dishes and reset the palate.

Roasted malt flavors bridge to chocolate, coffee, caramel, and charred meat; the darker the crust, the darker the beer can go.

Citrus and tropical hop aromas echo citrus, herbs, and seafood; resinous or dank hops suit grilled meat and strong aged cheese.