Saturday, 19 March 2011

Oak and WW II

Britain's brewing industry ceased self-sufficiency long before the 20th century. I've already catalogued the dependence on imported hops and barley. But the raw materials for brewing weren't the only vital imports. Large quantities of oak were needed for barrels. And where did that come from?

Before I answer that question, I want to bang one of my favourite drums again. The one about whether British barrels were lined or not. It's a funny one, because finding definitive evidence has been remarkably difficult. If you think about it, it's not surprising that brewing texts make no mention of lining barrels. Why discuss something you don't do? The rare times the topic does crop up, it's in relation to continental practices. The evidence against lining is mostly indirect. Like how to treat new barrels to stop them adding a woody taste to the beer inside them. I've more such evidence below.

Britain's own native oak, while eminently suitable for barrels, had been used up long before WW II. If you've been paying attention to the discussion of the Burton brewers Baltic trade, you'll remember that it was often on a barter basis. In return for beer they took barrel staves. Memel oak it was usually called. Which, as the region in question has changed nationality a few times in the last couple of hundred years, is a more accurate designation than Poland or Russia. (I mentioned Memel to my son Andrew this morning while waiting for the bus. "That's the north of East Prussia isn't it?" Clever boy.)

In 1940, I can't imagine any oak was being shipped across the Baltic to Britain. It wasn't a new problem. The same difficulty arose during WW I. And during the Napoleonic Wars, in the period when Russia was allied with France.

American Oak.

One of the biggest problems facing brewers at the present time is that concerning cask timber. After Russian and Polish oak American oak is the material to which one's attention naturally turns in these times, and many brewers must be much concerned at the prospect of having to use a material so well known to communicate undesirable woody and other flavours to British ales, particularly those of pale ale type. English oak is stated to be devoid of these defects, but it is doubtful if sufficient of this material is likely to be available to alleviate the cask timber problem to any marked extent. It is to American oak, therefore, that one must look for relief, and the question immediately arises: How can this timber be treated in order to make it suitable for use with British top fermentation beers ?

It may as well be stated at once that there is no simple answer to this all-important question. The whole matter was gone into very thoroughly after the last war, and no very satisfactory conclusions were reached as to the cause and cure of the strong flavour communicated to beer by the use of casks of American oak. The problem turned out to be much more difficult and complex than was expected, so it is felt that a brief summary of the work carried out by Professors Groom and Schryoer may assist brewers to understand the nature of the problem.

The objectionable "woody" taint may be due to—

1. The use of the wrong species of oak ("American white oak" is a very broad term and many different species or types of oak may find inclusion in this collective name).

2. The felling of the right species of oak at the wrong season of the year.

3. The use of heartwood of an appropriate species which is either too old, or (what is more likely) too young.

The differences between the suitability of the various species included in the term "American white oak" for beer-cask making appear to be due, "not to any specific extractive which imparts a deleterious flavour to the beer, but rather to fundamental differences in the chemical and physical properties of the timbers themselves."

It was further found that the ability to impart the objectionable flavour was not produced by the method of cutting the staves, nor by the presence of sapwood, or by the presence of micro-organisms in the wood. The last point was gone into with special care, for the heartwood  of which the staves were made was found to contain large quantities of starch, which might have been expected to promote growth of moulds and bacteria. This was a feasible hypothesis, particularly since micro-organisms of these types are capable of producing curious "mouldy" or "musty" odours and flavours, not greatly dissimilar from the "taint" of American oak. It was found, however, that this hypothesis was incorrect, the "taint" being inherent in the timber itself and not due to microbiological action.
"The Brewers' Journal 1940" page 496. (Published June 19th, 1940.)

I think it's pretty clear that beer was coming into direct contact with the wood of the barrel. Otherwise how could the oak "communicate undesirable woody and other flavours"? What I don't quite grasp is why this problem should be so particularly acute with British type top-fermenting beers. Unless, of course, it's just because everyone else did line their barrels.

How did they overcome these problems with American oak? You'll have to wait for part two of the article. Or rather for me to transcribe part two. It was published almost three-quarters of a century ago.


Gary Gillman said...

Ron, I agree with the writer that American white oak has a pronounced taste, a good example of it is in American chardonnay wine. Unless the wine is the type cool-fermented in stainless steel, it will usually have a distinctive vanilla/creamy/coconut-like odour, one also noticeable and appreciated in bourbon whiskey.

French wood also has a peculiar taste, the classic Cognac taste is largely due to it in my opinion and it is interesting it is never mentioned for use in English beer, probably for the same reason American oak was disliked. True, similar oaks (Spanish) were used famously for Scotch whisky, but these were old casks that had held sherry, perfect for whisky but not for pale ale maturation I am sure.

Innis and Gunn in Scotland specialize in a line of beers intended to take character from the wood and I would think they use new or re-used American oak although I don't know for sure. I believe the I&G beers would be examples of exactly what the quoted writer didn't like, but they obviously appeal to many people and the I&G line has done very well. I think, as with American hops, it comes down to what you are used to...

I think too it is likely that wood was abandoned finally for real ale due to concerns with bacterial infection and brettanomyces, not with objectionable tastes as such. In other words, the feisty American wood could be tamed I believe, but wood was abandoned ultimately for different reasons. That would be my guess anyway because Scotch whisky today uses such casks and it doesn't taste like Chardonnay. (You need to clean the old staves well and re-char them for one thing).

I think I recall a partial exception for porter in that its character was felt not inconsistent with American oak, but it is telling that porter was going out by the time the remarks quoted were made.


Gary Gillman said...

Ron, I'd like to add that experience with some beers has convinced me that American oak can enhance flavour. The best example are stouts stored for a time in barrels that formerly held bourbon, these are really good. Innis & Gunn issue a number of beers also held in casks that formerly held spirits, one is rum-finished I think they call it, another saw time in barrels that had held Canadian whisky. These also are excellent. I wonder what the 1940's author would have thought of these.

He would not I think have liked beers held in plain American oak wood, but probably at the time it was out of the question to consider using casks that had formerly held spirits or even sherry.


Martyn Cornell said...

I wonder how many brewers were still finishing off their fermentations in the "carriage casks" - certainly Batemans were until at least the early 1950s, and this would, surely, encourage "oaky" flavours to come out of the wood.

Thomas Barnes said...

Given that most cask English ale was served very young, I'm not sure that oak species would matter that much. It normally takes at least two weeks to a month for wood character to be noticeable.

Also, given that some degree of astringency was expected in many early 20th British ales (at least if Kris England's recipe results can be taken at face value), a slight amount of tannin might not have been out of place.

That said, there are things you can do to reduce or eliminate oak character - but I'll let Ron tell the story.

The Professor said...

I agree with Gary that American oak can enhance the flavor of some beers, a long as the oak character is not overdone.

I base my view on firsthand experience as one who is old enough to have consumed quite a bit of the celebrated Ballantine (Newark, NJ, USA) IPA which besides its remarkably intense but clean bitterness and its legendary hop aroma, also famously had a distinct note of oak from the storage wooden storage vats in which it was aged.

I have within the last 2 months sampled bottles of both the IPA and the Burton Ale they produced and while after 40-50 years in the bottle the hops had faded considerably, the unmistakeable character of the oak remained. Maybe I got lucky with the bottles I've procured, but the beers that I sampled were still very drinkable and distinctive, due in large part to that oak character that remained after all these years (the Burton having held up particularly well).