Why your beer loses its head in the glass

May 10, 2025

Check the glass before you blame the beer

Here's the order to work in, because it'll save you money. A head that forms on the pour and then falls away within a minute is usually a glass problem, and a beer that never forms much of a head at all is usually a beer problem. They're two different faults with two different fixes, and people spend a fortune on the second one when what they've got is the first.

Foam is a fragile structure of protein holding gas, and fats and oils tear it apart on contact. A film of dishwashing liquid left behind by a quick rinse will do it. So will rinse aid in a dishwasher, a tea towel that's been near butter, a greasy fingerprint inside the rim, and lipstick.

What a beer clean glass actually means

The old publican's test still works. Rinse the glass with cold water, and if the water sheets evenly down the inside and clings, the glass is clean. If it beads up and runs off in channels there's a film on it, and your head is going to die in that glass.

Getting there is straightforward. Wash with a dedicated brush and hot water, use a small amount of unscented detergent rather than the usual stuff, rinse properly with cold water, and let the glass air dry upside down instead of drying it with a towel. Keep a couple of glasses for beer and keep everything oily out of them.

Rinse the glass with cold water immediately before pouring too. A wet glass gives the foam less to grab at as it slides down, so the pour is gentler and the head lasts longer.

If the glass is clean and the head still won't hold

Then it's the beer, and it's nearly always one of three causes, which are worth knowing apart.

Not enough carbonation. No gas, no foam. Bottle conditioning needs a measured sugar dose and a couple of weeks somewhere warm enough for the yeast to work, and a bottle that has been sitting in a cold shed since the day you filled it may simply not have carbonated yet.

Not enough protein and dextrin. Foam is held up by proteins and larger unfermentable sugars, and plain white sugar contributes neither of those. A batch fermented on straight sugar is thinner in every sense, and the head goes first.

Something oily in the beer itself. Rare, but it happens. Residue in a fermenter that got washed with the wrong thing, or a bottle that held something else first.

The fix on the beer side

Swap part of the sugar in your next batch for dry malt extract. Dry malt is malted barley dried to a powder, and unlike sugar it brings proteins and dextrins with it. That is exactly the stuff that builds a head and holds it up. Around 250g to 500g in place of some of the sugar in a 23 litre batch makes a difference you can see in the glass.

Worth being accurate about what that does though, because it gets oversold. Most of dry malt is fermentable and will turn into alcohol like any other sugar would. What it adds on top is the fraction the yeast can't touch, and that fraction is where the body and the foam come from. It isn't magic and it isn't a rescue for a batch already in the bottle, it's a better starting point for the next one.

Shop related products

Coopers Light Dry Malt 500g. Proteins and dextrins that plain sugar doesn't bring.
Coopers Brew Enhancer 2 1kg. Malt and dextrose blended, if you want the middle road.
Coopers Light Malt Extract 1.5kg. The liquid version, if you want more body again.
Coopers Dextrose 1kg. What to use less of, if head retention is the thing bothering you.

Did you know we also stock the gear that isn't on the website, including fermenters, a hydrometer and test jar, airlocks, bottle brushes, crown seals, cappers, carbonation drops, no rinse sanitiser and brew sanitise. Give us a ring on (08) 8536 4333 to check what's on the shelf.

More in the beer supplies range, and Brewhilder will help you sort a batch that isn't behaving.