How do you clean beer glasses so that you don't kill the beer?

Grease and soap residue disrupt the thin liquid film around each air bubble, so that the bubbles merge faster and the head collapses.

Foam consists of gas held together by thin liquid films. Researchers at ETH Zürich showed in 2025 that proteins keep the films stable, with LTP1 from malt as the key substance. What those proteins build up, a thin film of fat in the glass can break down again. A fingerprint on the inside, a bit of butter or a thin film of washing-up liquid is enough for that.

Fill the glass with water, pour it out and watch how the water runs off: with a clean glass it runs off in a closed film without separate droplets.

The Brewers Association calls this the sheeting test. If droplets or streaks are left behind, there is still grease or soap in the glass. A second indication you see while drinking: with a clean glass, a ring of foam stays on the wall after every sip. If the inside stays completely smooth, the glass is not clean enough.

Wash beer glasses separately from greasy tableware, in three steps: washing, rinsing and rinsing again with clean water.

The Brewers Association describes this three-sink method for the hospitality trade, and it works just as well at home. Use a brush or cloth that is only used for glasses, so that no grease from pans gets transferred. Then rinse the detergent off completely, because the manual stresses that every trace must be rinsed away. Finally, place the glasses upside down on a rack and let them air dry.

Beer glasses may go in the dishwasher, provided there is no greasy crockery with them and no film of detergent or rinse aid is left behind.

Grease from pans and plates settles on the glasses during the cycle, and that is exactly what breaks the foam head. So run beer glasses separately or together with other glassware. The Brewers Association stresses that every trace of cleaning agent must be rinsed away completely. Then check the result with the sheeting test, and rinse the glasses by hand if droplets cling.

Rinse the clean glass cold just before use and then pour with the glass tilted, so that the head forms gradually rather than all at once.

A dry, warm glass releases the carbon dioxide all at once. A glass rinsed cold slows that down. First hold the glass at an angle, aim the stream at the side and set the glass upright towards the end to build the head. Nederlandse Brouwers keeps to about 2 centimetres of foam, at a serving temperature of around 6 degrees for light beers and around 10 degrees for stronger ones.