Glossary

The words these pages use, in a sentence or two each. Where a term has a page of its own, it is linked.

The numbers

OG, original gravity. The density of the wort before fermentation, relative to water. 1.050 means five percent denser than water, and most of that is sugar.

FG, final gravity. The density after fermentation. The gap between OG and FG is what the yeast ate, and the alcohol comes from it.

ABV. Alcohol by volume, worked out from OG and FG.

Plato and Brix. Two scales for the same thing as gravity, in percent sugar by weight. Brix is what a refractometer reads. Pick either in Settings.

IBU. International Bitterness Units, an estimate of iso-alpha acids in the finished beer. The app offers three models for it; see the FAQ.

BU:GU. Bitterness units over gravity units, a quick ratio for how dry or sweet a beer will read. 0.5 is balanced for most ales.

SRM and EBC. Two color scales. EBC is roughly twice SRM. The vitals rail shows whichever you chose.

MCU. Malt color units, the raw sum of each malt’s color times its weight, before the Morey curve turns it into a color a beer can actually be.

Attenuation. How much of the sugar the yeast consumed, as a percentage of the original gravity. The apparent figure, which is what labs publish and the app uses, overstates the real one because alcohol is lighter than water.

Efficiency. How much of the malt’s sugar reached the kettle. Mash efficiency is measured at the end of the mash; brewhouse efficiency is measured in the fermenter and is lower because of what is left behind. Both live on the equipment profile.

PPG. Points per pound per gallon, a malt’s yield expressed as the gravity one pound gives one gallon. The catalog derives it from the maltster’s extract figure; a row can override it.

Extract, FGDB. Fine-grind dry-basis extract, the maltster’s own yield figure as a percentage of dry mass. The number PPG comes from.

Diastatic power. A malt’s enzyme content, in degrees Lintner. It decides whether a grist can convert itself.

Lovibond. The color scale malts are sold in, close to SRM.

Hops

Alpha acid. The bittering compound, as a percentage of the hop’s weight. The number on the packet, and the one that drives IBU.

Cohumulone. One of the alpha acids, blamed for harsher bitterness at high proportions.

First wort hopping. Hops added to the kettle as it fills, before the boil, for a rounder bitterness. See Hops.

Whirlpool, hop stand. Hops added after the boil while the wort is still hot. They still isomerise, less as the wort cools, which the app models.

Dry hop. Hops added to the fermenter for aroma. No bitterness.

Cryo. Concentrated lupulin powder with the vegetal matter removed, roughly twice the alpha of the cones it came from.

Garetz. The storage model the app uses to age a hop’s alpha.

Yeast

Pitch rate. Cells per milliliter per degree Plato. The app’s defaults are 0.75 for ales and 1.5 for lagers. See Yeast and pitching.

Viability. The share of a pack’s cells still alive, which falls with age.

Starter. A small batch of wort used to grow more yeast before pitching. Never for dry yeast.

Flocculation. How readily a strain clumps and drops out of the beer when it is done.

STA1, diastaticus. A gene some strains carry that lets them ferment dextrins other yeasts cannot, which keeps going in the bottle. The catalog shows the lab’s result, or “unknown” where none is published.

Kveik. Norwegian farmhouse yeast that ferments hot and fast.

Mash and water

Mash pH. The acidity of the mash, which the enzymes care about. The water panel predicts it from the grist and the water.

DI pH. Distilled-water pH, the pH a malt would give mashed in pure water. Some maltsters publish it; the catalog says which.

Buffering capacity. How hard a malt resists a change in pH. Published by a few maltsters, defaulted by class for the rest.

Residual alkalinity. The part of the water’s alkalinity that survives the calcium and magnesium in it, and pushes the mash pH up.

Sparge. Rinsing the grain with hot water after the mash to collect the sugar.

Decoction. Pulling part of the mash, boiling it, and returning it to raise the temperature. See Decoctions.

Trub. The sludge of protein and hop matter left in the kettle and the fermenter, and the reason volumes go down at each step.

Packaging

Volumes of CO₂. How much carbon dioxide is dissolved in the beer, as a multiple of the beer’s own volume. 2.4 is a typical ale.

Residual CO₂. What is already dissolved when fermentation ends, which depends on the warmest the beer got afterwards.

Priming. Adding sugar at packaging so the yeast carbonates the beer in the bottle or keg. See Packaging.

Spunding. Sealing the fermenter under pressure so the fermentation’s own CO₂ carbonates the beer.

The app

Catalog. The built-in library of ingredients and styles, with a version number. See Ingredients.

Spec sheet, representative. The two kinds of catalog figure: the maker’s own published numbers, or class-typical values where the maker publishes none.

Snapshot. A recipe copies an ingredient’s numbers when you add it, so a catalog update never moves an old recipe.

Lot. One purchase of one ingredient in your inventory, with its own price and date.

Profile. A saved set of equipment, water, mash or fermentation settings a recipe refers to. See Profiles.

Batch. One brewing of a recipe, with its dates, readings and notes. See Brew day and batches.

Cellar task. A dated action on a batch: a dry hop, a transfer, a packaging day. See The calendar.

Named version. A frozen copy of a recipe you chose to keep. See Recipe history.

Provisional style. A BJCP style published between editions, numbered X1 upward. See Styles.

Guest workspace. Everything you make before signing in, kept on this device. See Offline.