Beer myths examined
Was beer stronger in the past?
“Beer used to be much stronger, and has been progressively watered down over time.”
True for twentieth-century Britain, where wartime taxation and grain restriction cut average strength sharply and it never fully recovered. Not true as a general rule: brewing has always made strong and weak beer side by side, and most historical beer by volume was weak.
Where the claim holds
British beer really did get weaker, and the cause is documented. The First World War brought grain restrictions and a tax structure calculated on gravity, which gave brewers a direct financial reason to reduce strength; the Second did the same again. Average original gravity fell substantially across both periods and did not return to pre-war levels afterwards, because tastes and tax had both adjusted around the new normal.
This is a specific, dated, well-evidenced change in one country, driven by policy. It is also the source of the general claim, which has been extrapolated far beyond it.
Where it does not
Most beer in most periods was weak. Small beer — the second running from a strong mash, at one to three per cent — was an entire everyday tier that has since vanished, and it accounted for a great deal of what was actually drunk. A historical drinker was more likely to be drinking something weaker than a modern lager than something stronger.
Strong beer existed alongside it and always has. Brewing has consistently made a range, and comparing the strongest historical beers with the average modern one produces the illusion of decline.
And modern beer has gone the other way
The craft era has pushed average strength up, not down. Double IPA, imperial stout and barrel-aged beer are ordinary parts of the modern range at strengths that would have been unusual in most historical periods, and session-strength beer is now marketed as a deliberate choice rather than being the default.
What to keep
The British decline is real, dated and worth knowing, and it explains why bitter and mild sit where they do. What should go is the generalisation: historical brewing made strong and weak beer together, and the weak tier was the larger one.
Every myth page here has to answer this. A correction that leaves a reader with less than they arrived with is not an improvement, and the salvageable part is usually the better story.
Where the story comes from
A real British twentieth-century change, generalised into a universal claim about the past. It is helped along by survivorship: the historical beers anyone remembers by name are the strong ones.
Why it persists
Because it is true where it is most often said — in Britain, about the last century — and because "things used to be stronger" is a comfortable shape for a story about the past.
Questions
Why did British beer get weaker?
Wartime policy, twice. The First World War brought grain restrictions and a duty calculated on gravity, which gave brewers a direct financial incentive to reduce strength; the Second repeated it. Average gravities fell sharply and never returned to pre-war levels, because both taste and tax had settled around the lower figures.
Connected
What this is about: Ordinary bitter · Dark mild · Small beer
The record: British beer strength collapses through two wars
In context: Temperance, war and prohibition · Consolidation and revival
Last reviewed 2026-08-29.
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.
British average beer gravity fell sharply during and after both world wars, driven by grain restriction and by a duty calculated on original gravity, and did not return to pre-war levels.
Backed by a source Applies in United Kingdom.
Sources: Beer: The Story of the Pint — print; Campaign for Real Ale