conditioning
Blending
Combine beers of different ages or batches to produce a consistent or more complex result than any single batch would give.
What is actually happening
In gueuze, young lambic supplies residual sugar and old lambic supplies a mature culture; sealed together in the bottle they referment, producing carbonation and a beer neither could be alone.
In Flemish sour brewing and historically in British porter and old ale, aged and fresh beer were routinely mixed to balance acidity and freshness. Blending is a craft in its own right, and several respected gueuze producers blend without brewing at all.
Styles where this step is decisive
- Gueuze
A blend of young and old lambic, refermented in bottle — intensely complex, bone dry and Champagne-like in its carbonation.
- Flanders red ale
A deep red sour ale matured for years in oak foeders, balancing sharp acidity against dark fruit and a vinous depth.
- English porter
The original dark British beer: chocolate and light coffee over a nutty malt base, restrained rather than aggressive.
- Fruit lambic
Lambic refermented on whole fruit — traditionally sour cherry or raspberry — producing a dry, tart, intensely fruity beer.
- Oud Bruin
An East Flanders aged brown ale, maltier and less sharply acidic than Flanders red, with raisin and caramel depth.
- Lambic
Spontaneously fermented Belgian wheat beer, matured in oak for years — funky, acidic, dry and unlike any other beer.
Related steps and concepts
- Spontaneous fermentation — What produces the components.
- Bottle conditioning — What the blend then does in the bottle.
Also at the conditioning stage
Barrel ageing · Cask conditioning · Cellar conditioning · Conditioning · Dry hopping · Freeze concentration · Lagering
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.
London porter brewing routinely blended aged, lightly-soured stock beer with fresh beer, so a degree of Brettanomyces and lactic character was a normal part of the style rather than a fault.
Backed by a source
Sources: Historical brewing log transcriptions and analysis; Beer: The Story of the Pint — print