How to taste beer: steps, aromas, off-flavours and a scoring sheet

Getting ready

• A clean glass, rinsed with clear water. A trace of washing-up liquid or a greasy glass kills the head. A tulip or stemmed glass that narrows at the top concentrates the aromas; a plain tumbler will do if you use it for all your tastings.
• A place without strong smells: no cooking under way, no perfume, no candles.
• Still water and white bread or plain crackers to clear your palate between two beers.
• A small amount, 10 to 15 cl per beer when you taste several.
• An order: from the lightest to the strongest, from the least bitter to the most bitter, sour and smoked beers last. A very hoppy beer crushes the next one.

Temperature changes everything: too cold, a beer smells of almost nothing and seems more bitter; too warm, the alcohol and the faults stand out.

When in doubt, serve a little colder and let the beer warm up in the glass: you can follow it changing over the minutes.

The steps of a tasting

• Look: pour with the glass tilted, then straighten it to form two to three fingers of head. Observe the colour, clarity and head in daylight, against a white background.
• Smell: a first time without swirling, in short sniffs, for the most delicate aromas; a second time after swirling the beer in the glass. First impressions are the most accurate: the nose gets used to a smell within a minute.
• Taste: a generous sip that covers the whole tongue, held for a few seconds. Then a second sip: swallow and breathe out through your nose with your mouth closed. This is retronasal smell: a large part of what we call taste is actually smell, perceived through the back of the throat.
• Wait for the finish: what remains in the mouth ten to thirty seconds after swallowing. Dry or sweet, short or long, bitter or soft.
• Write it down: a score from 1 to 5 per criterion, any off-flavours and a few words. Write straight away: the memory of a beer fades fast, and comparing your notes from one batch to the next is how you improve.

Appearance: colour and clarity

Colour comes almost entirely from the malt: pale malts give a straw or golden beer, caramel malts an amber or copper one, roasted malts a brown or black one. It is measured in EBC.

The planned colour of a recipe can be calculated before brewing with the EBC colour calculator.

Clarity ranges from brilliant to hazy. Haze is not a fault in itself: a wheat beer, a witbier or a NEIPA are cloudy by nature. In other styles, haze comes from yeast still in suspension (beer too young or sediment poured), from proteins (a haze that appears when cold and disappears as the beer warms) or, more rarely, from an infection.

The head: retention and lacing

• The height when poured and the size of the bubbles: a fine, tight foam lasts longer than a coarse one.
• Retention: how long it stays before collapsing. A good head lasts several minutes.
• Lacing: the rings it leaves on the glass with each sip.
• Colour: white, cream, beige or tan depending on the malts.

The head comes from malt proteins and hop compounds. Wheat, oats and caramel malts help it. Fat damages it: a badly rinsed glass, lipstick, crisps. A beer with little carbonation foams little; an over-carbonated beer foams a lot then collapses quickly.

Aroma on the nose

Start with intensity: faint, clear, powerful. Then look for where what you smell comes from. Aromas fall into three main families, those of the three ingredients that produce them:

• Malt: grain, bread, biscuit, honey, caramel, toffee, nuts, toast, coffee, chocolate.
• Hops: citrus, tropical fruit, stone fruit, resin and pine, flowers, grass, spice, earth.
• Yeast: fruit (banana, pear, red apple), clove, pepper, and sometimes a light sulphur smell in a young lager.

On top of these come the aromas of added ingredients (fruit, spices, wood, coffee) and those of off-flavours, described below. A balanced beer lets several families come through; an IPA puts hops forward, a German wheat beer the yeast, a stout the malt.

The aroma wheel in words

Putting a precise word on a smell is the hardest part. This table links the most common descriptors to what produces them, which also helps you find the ingredient in the recipe.

To train, smell the ingredients themselves: a handful of grains of each malt, a hop pellet rubbed between your fingers. You will then recognise their trace in the beer far more easily.

Flavour in the mouth

In the mouth you find the aromas from the nose again, plus the tastes the tongue perceives: the sweetness of the malt, the bitterness of hops and roasted malts, sourness (normal in a sour beer, a fault elsewhere), more rarely saltiness (in a gose).

The main question is balance: does the beer lean towards malt or towards hops? The BU:GU ratio predicts it from the recipe: around 0.5 the beer is balanced, below 0.4 it leans towards malt, above 0.8 bitterness dominates.

Also note how it develops: what comes first, what follows, and the finish. A dry finish makes you want another sip; a sweet, sticky finish tires quickly.

Body: texture and fullness

Body is the feeling of weight and texture in the mouth: light and almost watery, medium, or full and round. It depends mostly on the sugar left after fermentation, so on the final gravity. A beer that fermented far (high attenuation) is dry and light; a beer that keeps a lot of unfermentable sugars is round. The attenuation calculator measures how much was fermented.

Texture can also be silky or creamy (oats, wheat, nitro serving). In a strong beer, the warmth of alcohol is part of the body: soft and enveloping, it is a quality; burning, it is a fault (see solvent).

Bitterness: intensity and quality

Bitterness is judged on two points: its intensity and its quality.

Intensity is measured in IBU, but perception depends on the rest of the beer: 40 IBU dominate a light beer and go almost unnoticed in a dense, sweet one. The IBU calculator gives the value for a recipe.

Quality matters as much as quantity. There are several families of bitterness:

• Hop bitterness: clean and crisp, it fades quickly after swallowing. It can be herbal, resinous or zesty depending on the hops.
• Roasted bitterness: that of coffee and dark chocolate, brought by the roasted malts of stouts and porters, even with few hops.
• Harsh bitterness: rough, catching the throat and lasting a long time. It often comes from too much dry hopping, very sulphate-rich water or a lot of high-cohumulone hops early in the boil.

Bitterness is not astringency: bitterness is a taste, astringency a dry, rough feeling in the mouth, like over-brewed tea (see astringency).

Finally, note its persistence: short, medium or long.

Carbonation

Carbonation is the amount of dissolved carbon dioxide, in volumes of CO2. You feel it as a prickle on the tongue and as roundness or liveliness.

• Low, 1.5 to 2 volumes: English ales, served lightly sparkling.
• Medium, 2.2 to 2.7 volumes: most European lagers, stouts and pale ales.
• High, 3 volumes and more: German wheat beers, gueuzes, many Belgian beers.

A colder beer feels more sparkling and holds its gas better. Carbonation by style gives the target range for 18 styles. A flat homebrew has often lacked sugar or warmth while conditioning; a gusher was bottled before fermentation finished, over-primed, or is infected.

Overall impression

The last criterion sums up the others: is the beer pleasant, balanced, does it make you want more? If you were aiming for a style, does it resemble it? For your own beer, add a line on what you would change next time. It is the most useful note to read again.

Common off-flavours and their causes

An off-flavour is an aroma or taste that should not be there. Some are acceptable at low levels in a few styles, but most point to a specific problem in brewing, fermentation or storage. For each one: what you perceive, the likely cause and how to avoid it.

Diacetyl: butter, popcorn

A smell of melted butter, butterscotch or popcorn, sometimes a slick feeling in the mouth. Yeast produces diacetyl during fermentation and reabsorbs it afterwards, if given the time. Likely causes: fermentation stopped or racked too early, yeast that dropped out too fast, a lager without a diacetyl rest; more rarely a bacterial infection. To avoid it: let fermentation finish calmly, and for a lager raise the temperature to 16-18 °C for two to three days at the end of fermentation. A trace is accepted in some English ales and Czech lagers.

DMS: cooked corn

A smell of tinned sweetcorn, cooked vegetables or cabbage. DMS comes mainly from very pale malts such as pilsner. It evaporates during the boil but forms again as long as the wort stays hot. Likely causes: a boil too weak, too short or covered, slow cooling. To avoid it: boil vigorously with the lid off, 60 to 90 minutes with a lot of pilsner malt, and chill fast.

Acetaldehyde: green apple

A smell of crisp green apple, raw pumpkin or fresh paint. It is a normal stage of fermentation that the yeast then converts. Likely causes: beer too young, racked or bottled too early, too little yeast; more rarely oxidation. To avoid it: leave the beer on its yeast a few days after fermentation seems finished, and pitch enough yeast (see the pitching rate).

Oxidation: cardboard, sherry

A smell of wet cardboard, paper, old honey or sherry; hops lose their brightness and the colour darkens. An oxidised hazy IPA turns grey or brown. Likely causes: oxygen picked up after fermentation (splashy transfers, a large air gap in the bottle), storage too long or too warm. To avoid it: transfer without splashing, tube at the bottom, fill bottles to the top, store cold and drink hoppy beers young. In a long-aged strong beer, a light sherry note can be welcome.

Phenolic: clove, medicinal

A smell of clove, smoke, medicine, sticking plaster or plastic. Clove is normal in a German wheat beer, a saison or many Belgian beers: it comes from their yeast. Elsewhere, likely causes: wild yeast (infection), or chlorinated tap water and poorly rinsed chlorine sanitiser, which give a very persistent medicinal smell. To avoid it: remove chlorine from the water (activated carbon filter, or one metabisulphite tablet for about 75 litres), rinse chlorine sanitisers, keep things clean.

Solvent: fusel alcohols, nail varnish

A warmth that burns the throat, a smell of nail-varnish remover, varnish or glue. These are fusel alcohols and esters produced by stressed yeast. Likely causes: fermentation too warm, especially the first days (an active fermentation heats the wort by several degrees), too little yeast, poorly aerated wort. To avoid it: control the temperature from pitching, pitch enough yeast and aerate the cooled wort.

Sour: tart

Yoghurt, lemon or vinegar sourness in a beer that should not be sour. Likely causes: infection by lactic or acetic bacteria, often with haze and carbonation that keeps rising in the bottle. To avoid it: clean then sanitise everything that touches the cooled wort, replace scratched tubing and buckets. Sourness is intended, however, in a Berliner weisse, a gose or a lambic.

Astringency: dry mouth, tannins

A dry, rough feeling in the mouth, like over-brewed tea or grape skin. These are tannins (polyphenols) extracted from the grain husks or the hops. Likely causes: sparging too hot (above 78 °C) or too long, sparge pH too high, grain milled too fine, a lot of dry hops, too much roasted malt. To avoid it: sparge at 75-78 °C, watch the pH, keep dry hopping reasonable.

Metallic

A taste of coins, iron or blood. Likely causes: iron-rich water, poorly maintained metal equipment (rust, welds, unpassivated vessel), oxidised caps. To avoid it: clean, passivated stainless steel and low-iron water.

Lightstruck (skunky)

A smell of skunk, cabbage or burnt rubber as soon as the bottle is opened. Sunlight or fluorescent light breaks down hop bitterness into a very smelly sulphur compound, in just a few minutes. Likely causes: green or clear bottles, beer left in the sun, even in the glass. To avoid it: brown bottles kept away from light.

Sulphur: struck match, egg

A smell of struck match or rotten egg. Some yeasts, especially lager yeasts, produce it during fermentation; the smell disappears during conditioning. Likely causes: beer too young, stressed or nutrient-starved yeast. To avoid it: allow conditioning time, with healthy yeast in sufficient quantity. If the smell persists with a brothy taste, see yeast.

Yeast: autolysis

A taste of fresh yeast, raw dough or, more seriously, broth, soy sauce, meat or rubber. A fresh-yeast taste often comes from sediment poured into the glass. A brothy taste comes from autolysis: dead yeast cells breaking down. Likely causes: beer left for weeks somewhere warm on a thick yeast bed. To avoid it: do not leave the beer on the yeast too long in the warm, store bottles cold and leave the last centimetre in the bottle when pouring.

A sheet to score

Krausi's tasting sheets score each criterion from 1 to 5. So that scores can be compared from one time to the next, here is what the extremes mean.

Homebrew competitions often use the BJCP scoresheet, out of 50 points: aroma 12, appearance 3, flavour 20, mouthfeel 5, overall impression 10. It weighs aroma and flavour more heavily; the 1-to-5 sheet per criterion is simpler for following your own beers.

With several people, everyone scores on their own before talking: the first remark said out loud influences everyone. And to know whether a recipe change can really be tasted, nothing beats a blind tasting: two glasses of the same beer and one of the other, without knowing which is which.