How to taste sour beer without the acidity flattening your palate

Why acidity is hard on the palate

Acidity makes your mouth water and leaves a puckering, drying feel. It also dulls your sensitivity to sweetness and to some aromas for a while afterwards. After a strong sour, a delicate lager can taste thin and almost sweetish.

Most sour beers sit at a much lower pH than ordinary beer. A Berliner weisse can be well below the 4.0 to 4.5 typical of most beer, often in the low 3s. That is closer to a squeeze of lime than to a lager. If you are new to the family, our guide to sour beer for beginners describes the main styles.

Taste sours last, or alone

In a mixed flight, put sour beers at the end. If you want to compare several sours properly, give them their own session. Start with the gentlest, such as a Berliner weisse or a light gose, then move to fruited sours, then to the most acidic or funky beers like lambic-style or wild ales.

Our guide to Berliner weisse is a good starting point: it is light, low in alcohol and clean in its acidity, which makes it a useful reference before stronger examples.

Spacing matters as much as order. If you are judging a mixed flight that must include a sour, leave a gap of several minutes after it. Use that time for water and a plain cracker before you return to anything delicate. Better still, finish with the sour and stop.

Write your notes for each sour before tasting the next one. Acidity blurs memory as well as taste. Three sours tasted in a row tend to merge into one impression by the end.

Small sips and the first sip rule

The first sip of a sour beer is a shock to the palate. Treat it as a warm-up. Take a small sip, let it settle, then take the sip you actually judge. Most experienced judges score from the second or third sip of a sour, not the first.

Pour small, around 50 to 60 ml. You need less sour beer to judge it than you do with a pale ale, because acidity dominates quickly. Serve at around 6 to 10 °C. Very cold hides the fruit and funk. Too warm makes the acidity feel harsher.

Looking past the sourness

Sourness is the loudest note but rarely the most interesting. Once you are used to it, look for what sits behind.

• Type of acidity. Clean lactic sourness is soft, like yoghurt or lime. Acetic sourness is sharp, like vinegar. In more than a trace it is usually a fault.
• Fruit. In fruited sours, does it taste of real fruit or of fruit syrup? Is it ripe mango or sweet mango candy?
• Funk. Wild yeasts such as Brettanomyces bring farmyard, leather, hay or tropical fruit notes.
• Malt and body. A good sour is not just acid and water. There should be some grain, some weight and a balancing sweetness.
• Finish. Does it end clean and refreshing, or does the acid linger harshly?

Deliberate sour or infected beer

A sour style is soured on purpose, with chosen bacteria and yeast. It should taste balanced and intentional. An infected beer is a beer that was never meant to be sour. Sourness in a pale ale, an IPA or a lager is a fault.

Infected beers often show other signs too: a buttery note from certain bacteria, a vinegar edge, a film on the surface, gushing when opened or haze in a beer that should be clear. Our guide to sour infection off flavours covers the causes. In warm Indian conditions, packaged beers stored hot can show these problems faster.

Resetting your palate

Between sour beers, drink water at room temperature and eat something plain and slightly starchy. Unsalted crackers or plain white bread help absorb the acidity. Some tasters find a little plain milk or curd helps between very acidic beers, though it is not standard on judging tables.

Give yourself a few minutes between beers rather than racing through. If you have tasted several sours, wait before going back to non-sour beers, or save the others for another day.

Learning to pick out the acid type, the fruit character and the faults takes practice with reference samples. That is hard to do alone and it is one of the most useful things a sensory course can teach.