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Monday, 8 July 2024

Where has all the dextrine gone?

In his introduction to the second edition of "The Theory and Practice of Modern Brewing" notes some of the reasons he has had to update his book. It's fascinating stuff. Especially when he talks about the change in wort composition.

It seems that this change was at least partly due to the switch in taxation from malt to the OG of the wort before fermentation. A change which had only taken place a few years earlier, in 1880. 

"For instance, since the abandonment of the malt duty, types of grain have come into use and methods of malting have been carried out that have led insensibly to the production of infusion worts almost entirely destitute of dextrine, or, at any rate, of dextrine in sufficient quantity to determine that persistent palate of beer that is thought so necessary, while as public taste has been drifting in the direction of a decided preference for low gravity beers in place of those of extreme body and strength, that were indeed so diligently sought after a few years ago, this question of infusion extract and its general composition has of necessity become more and more important."
"The Theory and Practice of Modern Brewing" by Frank Faulkner, 1888, page vi.

By "types of grain" I think he's talking about unmalted grains, such as flaked maize and flaked rice. Which I doubt produced much dextrine.

It's funny when he talks about the low-gravity that drinkers now prefer. These wouldn't be what we would consider low-gravity nowadays. The would have been at least 1050ยบ.

The typical dextrine content of wort had about halved, from 20-22% to 10-12%. Quite a big change.

"It is well known, I think, that the theoretical transformation products of malt starch (or rather of malt extract) contain, as a rule, about 60 or 62 per cent, of maltose and 20 or 22 per cent, of dextrine, while for reasons in connection with altered character of material, the adoption of low infusion heats, subdivision of mash wort, and stewing during collection process, this theoretically normal composition of wort extract is no longer very common, the ordinary dextrine constituent in the case of infusion worts having diminished to a proportion not exceeding, as a rule, some 10 or 12 per cent, upon total solids.

I am not saying or wishing my readers to infer for a moment that the dextrinous bodies are the sole constituents of wort capable of communicating body, viscidity, or foaming capacity to resulting beer; but they are, at any rate, of very great importance, the exact percentage in which they exist having much to do not only with the condition of beer, but the way in which it matures during lengthy storage."
"The Theory and Practice of Modern Brewing" by Frank Faulkner, 1888, page vi.

The decline in the public's enthusiasm for aged beer would also have had an effect. Beers served no more than a couple of weeks after racking didn't need a high dextrine content to provide fuel for the secondary fermentation.

3 comments:

  1. Christoph Riedel8 July 2024 at 07:39

    I am wondering whether at the time they could separately analyse the wort for dextrins and proteins or whether they just read the final gravity and assumed all that was left was dextrins.

    At the time of writing there was much debate about "pure beer" being made from malt only and one of the main counter-arguments was that the demand for clarity in beer, which had been pushed by the arrival of glasses in pubs, made it necessary to adjust the protein content of the beer to the right level. For that they employed grains, sugar and foreign barley, which all had a lower protein content than most domestic barley. That's why especially Faulkner's first paragraph reminds me more of protein than of dextrins.

    Regarding the second paragraph stating "low infusion heats", do you have any recipes that agree with this statement? Did mash temperatures drop around 1880?

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  2. I didn't realise Truman's ever sold their Old Stock Ale straight. Derek Prentice told me it was incredibly acidic and blended into the Barley Wine.

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  3. I am trying to reconcile in my head how all of this was perceived by the drinker once the final beer was in the glass. The highly dextrinous beers of old that were ‘so diligently sought after’ would have been quite different if sold staled (aged) versus mild (unaged). A high-gravity, dextrinous mild ale must have been noticeably full-bodied and viscous compared to a stale stock ale where most of the dextrins had been chewed up by secondary fermenters. (Those secondary fermenters were, presumably, mostly Brettanomyces.) But perhaps the by-products of the secondary fermentation resulted in body and ‘viscidity’ by other means – glycoproteins maybe, or glycerol? In any case, I'll assume those stale ales wouldn't have been dextrinous and would have been noticeably more acidic by the time they were served to the customer.

    So Faulkner's remark about the change in public taste covers two separate threads: first that public taste was shifting from viscous, heavy mild ales to lighter bodied – but still young, or mild – ales; and second that the characteristic flavours from stock ales were also falling out of fashion, meaning that, even if stock ales weren't so heavy and dextrinous, people still didn't fancy them. These two threads converged to bring about the same result in brewing practice, that is, a move to low-gravity, less dextrinous worts.

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