Beer without alcohol sounds like a contradiction: the alcohol is made by yeast, and yeast is what makes beer taste like beer. So brewers have four ways round it. Each one trades something away, and that trade-off explains why one alcohol-free beer tastes crisp and another tastes like sweet bread water.
Pick a route below to see the steps, what it does to flavour, and where the alcohol level usually ends up. The ratings are a rough guide to the method in general, not a score for any beer: a skilled brewer can make any route taste good.
Where this route usually ends up (ABV, alcohol by volume)
Check a bottle
Stopping early is the cheapest, because it needs no extra kit. The catch is sugar. If the yeast has not eaten the malt sugars, they stay in the beer, and the result can taste sweet and a bit like the raw malt liquid, which brewers call worty. Special low-alcohol yeasts and careful recipes are how brewers fight that.
Removing the alcohol is the route large breweries favour, but it needs expensive equipment. Alcohol boils at 78°C, lower than water, so heating can drive it off, but heat can damage flavour. Vacuum distillation lowers the pressure so the beer needs less heat. Reverse osmosis pushes the beer through a membrane that lets water and alcohol pass while holding back most of the larger flavour molecules, and some systems run cold for that reason.
Dilution works the other way round: brew something strong and over-flavoured, then water it down. It is tricky to keep body and fizz right once the water goes in.
Skipping the yeast gives a true 0.00%, but it also skips the flavours yeast normally makes, such as fruity esters. That can leave the beer sweet and one-note unless something replaces them.
Alcohol-free beer is not beer with the alcohol missing. It is a different recipe with a different job to do.
There is no single worldwide line for "alcohol-free". In the UK, guidance has long reserved "alcohol-free" for drinks at 0.05% ABV or less, calls beers up to 0.5% "de-alcoholised", and uses "low alcohol" up to 1.2%. In many other countries, including the US, a drink under 0.5% can be called alcohol-free or non-alcoholic. The UK has looked at moving its line, so rules can change.
The practical point: 0.0% on a label and 0.5% on a label are different beers. At 0.5%, a 330 ml bottle holds under 2 ml of pure alcohol, about a tenth of the same bottle at 5%, but it is not zero. Use the calculator above to see your own bottle.
If you avoid alcohol completely, for pregnancy, medication, driving or recovery, look for the lowest figure on the label and ask a doctor if you are unsure. These beers are for adults: many shops and some countries treat them like regular beer when it comes to age limits, so do not hand them to under-18s.
The ABV figure comes first, and the wording around it is second. Check whether it says 0.0%, 0.05% or 0.5%, because the same word can cover different strengths. After that, look for the method if the brewer tells you. "Dealcoholised" means the alcohol was taken out; "brewed to be alcohol-free" usually means the stop-early route. Then judge by taste: a sweet, doughy beer often means leftover sugar, and a thin one often means a lot was removed or watered down.