Following up on this, I should probably note that last week I finally managed to do a research-based broadcast in which a tiny particle of the research was actually done by me.

Last week’s edition of Radio 4’s Questions, Questions featured a piece (on the iPlayer, starts 22:49) inspired by that traditional historical-empathy favourite, “Was Everybody Drunk All The Time (in any given period)?”

Briefly summarised, the established and reliable answer to that question is

(a) Probably not, although it’s true that drinks we think of as alcoholic – usually beer – were staple in many areas of Britain until the nineteenth century, and indeed were often safer than water or milk. Beer to be drunk through the day, though, tended to be so-called “small” beer, too weak in strength to cause any noticeable intoxication. BUT!

(b) Those who could afford to – the rich, skilled artisans, and labourers where work was plentiful – did, sometimes, engage in cultures of round-the-clock and on-the-job hard drinking which seem ridiculously excessive by today’s standards. (How did they manage to get anything done? Forms of work requiring sober workmen tended not to develop where there were not sober workmen to do them. It’s sometimes suggested that nineteenth-century factory masters, whose systems were built around the rhythms of the machine rather than the worker, favoured temperance reform mainly for this reason.)

This was the basis of the answer I gave, while my ex-CHSTM colleague Kat Foxhall tackled the medical prescription of alcohol and the public health side more generally. As normal, the broadcast segments were edited from a longer interview covering a lot of material that wasn’t used: the world will, for instance, have to cope without hearing my thrilling historical variation on “Beer is not actually made from hops…”, the standard bit of exposition which all brewery tour guides eventually end up reciting in their sleep.

I was pleased, therefore, to find out that the one bit of original primary research I’d thrown in had made the cut. There’s a lot of established work on the effects of strong beer, but I’m interested in how the strength of beer – along with its various other properties – was determined and understood. The usual answers, until around 200 years ago, had very little to do with alcohol.

Gin and other spirits were obviously alcoholic: they were described by the proportions of alcohol and water they contained, and taxed on that basis. Beer was treated more as a foodstuff which happened to make you drunk if it was strong enough. Brewers defined its strength by how much malt was needed to make it; the taxation authorities rated it very simply as either “strong” or “small”, depending on its retail price. While it was certainly possible to distil alcohol from the beer, there was no obvious reason to do so. There are thus very few recorded figures for the alcoholic strength of beer before the nineteenth century, and none at all (that I can find) for small beer.

Can we be sure, then, that small beer didn’t make you drunk? Recipes published around 1760 suggest that to make one barrel of small might require one and a half bushels of malt, or perhaps two bushels. A competent twenty-first-century home brewer, using ordinary pale malt in the same ratio, might achieve 3.5% or more alcohol by volume: the strength of a respectable session bitter, reliably drunk-making over the course of several pints.

This figure, however, enormously overestimates the historical strength… probably. There are three main reasons for this. Firstly, a bushel of eighteenth-century malt yielded far less fermentable sugar than we get from a bushel of today’s ingredients. Probably. Secondly, eighteenth-century brewers’ yeasts transformed less of the sugars to alcohol. Probably. (This was often deliberate: the residual sugars were part of the drink’s appeal, helping to sustain the drinker. Pushing the fermentation to the limit was a distillery trick.) Thirdly, eighteenth-century equipment was much less sterile, and most beer would have turned somewhat sour by modern standards. The alcoholic strength would have fallen appreciably as a proportion of the alcohol turned to acid. Perhaps.

So, what was the alcoholic strength of eighteenth-century small beer? We don’t know.

The first value I have so far traced was recorded some time around 1818 by William Thomas Brande, Professor of Chemistry at the Royal Institution. Brande had been determining the alcohol content of drinks for several years, originally at the request (or insistence) of Joseph Banks. The project had probably started off as a typical piece of Banksian “science in the service of the State”: reliable alcoholometric data would help to standardise the tax regime, preventing controversy over the valuation of different drinks. Most of the early determinations concerned wine, but Brande’s table of values grew to include spirits, cider and various beers.

The average strength of small beer, said Brande, was 1.28% alcohol by volume. (Modern notions of error handling had not been established: Brande probably took a simple average across a small number of trials, and quoted it to the precision that fitted his table.) This compared to 4.2% for ordinary London porter, 6.8% for the more expensive “stout” porter, and 8.88% for the famously powerful Burton ale. (Joseph Banks, apparently, did not like to be outdone. Beer from the brewhouse on his Lincolnshire estate clocked in at 10.84%. Make of that what you will.)

If Brande’s values are representative, small beer in the final decades of its regular use was not very drunk-making at all. Brande’s average is a whisker above the 1.2% which legally defined “intoxicating liquor” from 1964, although the current legislation, of 1990, imposed a lower threshold of 0.5%. Oddly enough, until Brande’s work was widely accepted, it was not considered obvious that intoxication should be defined in relation to alcohol content at all. But that’s another story for another posting.

So much for my bit. The other 90% of the interview – by volume – consisted of the usual attempts to put across ideas found in other people’s work. Those who pay attention to these things might be interested in the following: