Adulteration

There are fascinating insights to be gained by comparing the gravity books and brewing logs. Specifically, what was happening to beer between leaving the brewery and being pulled into a customer's glass.

The brewing logs tell what the brewer intended his beer to be. The gravity books what was actually served in pubs. The two rarely match.

19th Century
Frederick Accum did something similar at the beginning of the 19th century. He sampled beers in the great Porter breweries and then in pubs. One average, by the time they were served, beers were 10 -15% weaker. A century or so later, not much seemed to have changed.

Samples of brown stout with which I have been obligingly favoured, whilst writing this Treatise, by Messrs. Barclay, Perkins, & Co.—Messrs. Truman, Hanbury, and Co.—Messrs. Henry Meux and Co.—and other eminent brewers of this capital—afforded, upon an average, 7,25 per cent. of alcohol, of 0,833 specific gravity; and porter, from the same houses, yielded upon an average 5,25 per cent. of alcohol, of the same specific gravity*; this beer received from the brewers was taken from the same store from which the publicans are supplied.

* The average specific gravity of different samples of brown stout, obtained direct from the breweries of Messrs. Barclay, Perkins, and Co. Messrs. Truman, Hanbury, and Co. Messrs. Henry Meux and Co. and from several other eminent London brewers, amounted to 1,022; and the average specific gravity of porter, from the same breweries, 1,108 [I think this should be 1,018].

It is nevertheless singular to observe, that from fifteen samples of beer of the same denominations, procured from different retailers, the proportions of spirit fell considerably short of the above quantities. Samples of brown stout, procured from the retailers, afforded, upon an average, 6,50 per cent. of alcohol; and the average strength of the porter was 4,50 per cent. Whence can this difference between the beer furnished by the brewer, and that retailed by the publican, arise? We shall not be at a loss to answer this question, when we find that so many retailers of porter have been prosecuted and convicted for mixing table beer with their strong beer; this is prohibited by law, as becomes obvious by the following words of the Act.

"If any common or other brewer, innkeeper, victualler, or retailer of beer or ale, shall mix or suffer to be mixed any strong beer, ale, or worts, with table beer, worts, or water, in any tub or measure, he shall forfeit £50." The difference between strong and table beer, is thus settled by Parliament.
"A Treatise on the Adulterations of Food" by Frederick Accum, 1820, pages 172 - 175.

20th century
The first thing that tipped me off to this possibility was the variation in gravity for different samples the same beer in the Whitbread and Truman Gravity Books. With the exception of traumatic periods like wartime, brewers didn't fiddle with the gravity of a beer from month to month. It stayed constant for years on end. I know that from the brewing logs. And they were professional enough to be able to hit the target gravity pretty much 100% or the time.

Sorry, I should have said variation in the gravity of draught beer. Bottled beers are much more constant. Which is a real giveaway as to the underlying cause: adulteration. The landlord can't really fiddle with bottled beer. Not so with draught beer.

Let's look at an example from Barclay Perkins. Here are five examples of their KK, or Burton, all from 1936. Four are from the Truman Gravity Book, one from the Barclay Perkins brewing logs.


The beer as brewed was a nice round 1056 gravity. The pub samples vary from 1048.8 to 1055.9. Only one matches the brewery gravity. As these have been calculated, we need to allow from some margin of error. So I'm willing to give the 1053.9 sample the benefit of the doubt. The other two are far too low. 10% and 13% too low to be precise. Something has clearly happened to the beer. But what?

My guess would be slops of weaker beer being put into the KK cask.

But take a look at the figures for Barclay Perkins ordinary Mild, X Ale:


Here all the pub samples have a higher gravity than the brewing log. How can this be? When I was younger, a reason people often gave for not drinking Mild was that the slops from all the other beers were put into it. Being dark, it was hard to spot. I was sceptical about this theory at the time. But that's exactly what these numbers suggest. As X would usually be the weakest draught beer, slops from anything else would raise its gravity.

This begs the question. Adulteration seems to have been common between 1800 and 1940. Does it still occur now?

Fredrick Accum

I'm a sucker for tables. What I always look for in brewing manuals or academic books are tables of data. Of particular interest (to me, at least) are tables of analyses of beers.

It's surprising how long ago the first chemical analyses of beer were made. Fredrick Accum detailed in his 1820 work "A Treatise on Adulterations of Food" a method for discovering the alcohol content of beer. The first thing he noticed was the difference in strength between examples of the same beer sampled at the brewery and in a pub.

Brown Stout: brewery 7.25% ABV, pub 6.5% ABV
Porter: brewery 5.25% ABV, pub 4.5% ABV

Looks a bit dodgy, doesn't it. This is what Accum says:

"Whence can this difference between the beer furnished by the brewer, and that retailed by the publican, arise? We shall not be at a loss to answer this question, when we find that so many retailers of porter have been prosecuted and convicted for mixing table beer with their strong beer;"

These are the results of his (and others) analyses:

Ale, home-brewed 8.30% ABV
Ale, Burton, three samples 6.25% ABV

*Repository of Arts, No. 2, p. 74.—1816. p222

Ale, Burton* 8.88% ABV
Ale, Edinburgh* 6.20% ABV
Ale, Dorchester* 5.50% ABV
Ale, common London-brewed, six samples 5.82% ABV
Ale, Scotch, three samples 5.75% ABV
Porter, London, eight samples 4.00% ABV
Ditto, Ditto† 4.20% ABV
Ditto, Ditto† 4.45% ABV
Ditto, Ditto, bottled 4.75% ABV
Brown Stout, 4 samples 5% ABV
Ditto, Ditto† 6.80% ABV
Small Beer, six samples 0.75% ABV
Ditto, Ditto‡ 1.28% ABV

* Copied from Professor Brande’s Paper in the Philosophical Transactions, 1811, p.345.
† Result of our own Experiments, see p.174.
‡ Professor Brande’s Experiments.

Accum also has some interesting things to say about Porter and Entire and the difference between the two:

"OLD, OR ENTIRE; AND NEW, OR MILD BEER.
It is necessary to state, that every publican has two sorts of beer sent to him from the brewer; the one is called mild, which is beer sent out fresh as it is brewed; the other is called old; that is, such as is brewed on purpose for keeping, and which has been kept in store a twelve-month or eighteen months.

. . . . porter is very generally compounded of two kinds, or rather the same liquor in two different states, the due admixture of which is palatable, though neither is good alone. One is mild porter, and the other stale porter; the former is that which has a slightly bitter flavour; the latter has been kept longer. This mixture the publican adapts to the palates of his several customers, and effects the mixture very readily, by means of a machine, containing small pumps worked by handles. In these are four pumps, but only three spouts, because two of the pumps throw out at the same spout: one of these two pumps draws the mild, and the other the stale porter, from the casks down in the cellar; and the publican, by dexterously changing his hold works either pump, and draws both kinds of beer at the same spout. An indifferent observer supposes, that since it all comes from one spout, it is entire butt beer, as the publican professes over his door, and which has been decided by vulgar prejudice to be only good porter, though the difference is not easily distinguished. I have been informed by several eminent brewers, that, of late, a far greater quantity is consumed of mild than of stale beer.

The entire beer of the modern brewer, according to the statement of C. Barclay, Esq. 'consists of some beer brewed expressly for the purpose of keeping: it likewise contains a portion of returns from publicans; a portion of beer from the bottoms of vats; the beer that is drawn off from the pipes, which convey the beer from one vat to another, and from one part of the premises to another. This beer is collected and put into vats. Mr. Barclay also states that it contains a certain portion of brown stout, which is twenty shillings a barrel dearer than common beer; and some bottling beer, which is ten shillings a barrel dearer; and that all these beers, united, are put into vats, and that it depends upon various circumstances, how long they may remain in those vats before they become perfectly bright. When bright, this beer is sent out to the publicans, for their entire beer, and there is sometimes a small quantity of mild beer mixed with it.'

The present entire beer, therefore, is a very heterogeneous mixture, composed of all the waste and spoiled beer of the publicans—the bottoms of butts—the leavings of the pots—the drippings of the machines for drawing the beer—the remnants of beer that lay in the leaden pipes of the brewery, with a portion of brown stout, bottling beer, and mild beer."

Source: Fredrick Accum "A Treatise on Adulterations of Food", pages 197 - 202

Entire sounds delighful, doesn't it? Mmm slops, lead-laden beer and a bit of Brown Stout. "Quart of Entire please, barman, and make it good and leady." I liked the imaginative use of beer engines to mix stale and mild Porter whilst pouring. I wonder if anyone still has a set with four handles but only three spouts?

It's reading passages like this that makes me realise how difficult it would be to truly recreate early 19th-century Porter. Reading the brewing logs is one thing, but as the beer never seems to have been consumed in its pristine state, they don't tell you the whole story. Sadly, I think health inspectors might prevent a faithful recreation.