dealcoholisation
Reverse osmosis
Remove alcohol by forcing beer against a membrane that passes water and ethanol while retaining larger flavour molecules.
Also called membrane separation, how alcohol free beer is made, alcohol free beer production.
What is actually happening
Pressure drives the beer against a semi-permeable membrane. The permeate — water and ethanol — is separated, the ethanol distilled off, and the water returned to the retained concentrate.
Because it runs cold, it is gentler on flavour than thermal methods. It is correspondingly slower and more expensive, which is why both approaches remain in commercial use.
Styles where this step is decisive
- Alcohol-free IPA
An alcohol-free beer built around heavy dry hopping, since hop aroma is added after fermentation and survives the process intact.
- Alcohol-free pale lager
A pale lager produced at or near zero alcohol, now the largest and most refined part of the no-alcohol category.
- Alcohol-free wheat beer
An alcohol-free wheat beer — often the most convincing of the category, because wheat body and yeast esters survive dealcoholisation well.
Related steps and concepts
- Vacuum distillation — The thermal alternative.
- De-alcoholisation — The vocabulary.
Also at the dealcoholisation stage
Arrested fermentation · Maltose-negative fermentation · Spinning cone column · Vacuum distillation
See the whole process in order on how beer is made.
Last reviewed 2026-08-16.
Evidence
What BeerHQ knows about this, and how. Every statement carries the state of the evidence behind it rather than being presented flatly as fact.
Membrane separation removes alcohol at ambient temperature rather than by heating, which is gentler on flavour than thermal methods and correspondingly slower and more expensive.
Backed by a source
Source: Technology Brewing and Malting — print