Tuesday, 19 January 2010

The weights of different malts

A short post today. Prompted by Graham Wheeler's comment on the Oat Mild post of a couple of days ago.

The image to right comes from inside cover of a Barclay Perkins log from the 1920's. It gives the weight (per half quarter) of a variety of different malts.

You'll note that they differ considerably, even different batches of the same type. The roasted malts, unsurprisingly, were lighter than pale malts.

Fullers were still measuring their malt in quarters in the 1960's, as were Whitbread.


Gary Gillman said...

On the point of oats, I found an interesting exchange from 10 years ago on a homebrewing forum in which our Jeff Renner participated. I was going to place an extract here but got preoccupied with another matter and now I can't find it again! But the gist was that while malted oats occasionally are used, they are not easy to work with and require careful milling and temperature control. One problem is they can lead to unclear worts unless again carefully handled. Jeff said they add can an excellent silky quality to stouts and he related a successful attempt to produce a home-brewed stout somewhat akin to Maclay Oatmeal Stout.

Flaked oats is a cooked and dried type in which the starches are gelatinized thus promoting easy use in the mash. I would think today most oats in brewing are not malted but do not know for sure.


Gary Gillman said...

Just one other point, to follow up on something Graham said regarding very small amounts of oats in mashbills of some pre-Second War English breweries.

He made the point this may have been done to allow marketing an oatmeal stout and thus meet trade descriptions laws.

This is possible, but I wonder if there was another reason, perhaps related to the idea that grains should be used which in a time of shortage, as indeed occurred in WW II, would become much more important. In other words, maybe it was felt brewers should buy enough collectively of such grains year in year out to warrant maltsters and others dealing in them. So that when time came to meet increased demand, the basis for it was there. This may have been almost an unconscious habit, perhaps one inherited from olden times when indeed mixed mashbill beers seem to have been common (Middle Ages and before). Such beers are still made, Samuel Smith has a range out currently which look most interesting.

Maybe too such usage in more modern times wasn't recorded always in brewing logs. I recall Graham suggested earlier that the logs in some cases at any rate might not completely reflect actual operating conditions.

The reason this line of thinking presents itself is because in Ireland (a country not a stranger to grain shortages at times), it was a constant practice of distillers, in what is now the Republic at any rate, to use very small amounts of rye, oats or wheat in a pure pot still mashbill. The bulk of that mashbill was composed of unmalted and malted barley, but a very small amount, 1% or 2% only, was rye, oats and/or wheat (perhaps maize in later years).

Now why was this? Could such small amounts have added much to the whiskey's character? Perhaps, but this seems hard to accept.

Irish Distillers closed the historic Jameson distillery in Dublin in the mid-1970's. It replaced it with the current modern plant in Midleton in the south. When that happened, I understand use of oats, rye and other grains other than barley was abandoned. I don't know why this was done, perhaps it was felt the trouble was too much.

Or maybe it was felt that by then, sufficient supplies of malted and unmalted barley could be assured on a permanent basis...



Ron Pattinson said...

Gary, for most of the 19th century barley was the only grain really used for brewing.

There was a good reason why oats weren't used: tax. Malt was taxed per bushel (i.e. by volume). Oats had the unfortunate property of being much lighter and containing less extract. A quarter of oat malt only had about half the extract of a quarter of barley.

When taxation was moved from malt to beer in 1880, oats lost this disadvantage. And oatmeal Stouts began to appear.

I've looked at thousands of brewing records and the only beers in which oats were used (with the exception of wartime) were Porters and Stouts. The quantities are so small that it's obviously just for legal reasons.

You see all sorts in wartime logs. Even things like malted rye.

Gary Gillman said...

Ron, thanks for that, but I ask myself, if oats became more desirable for cost reasons and therefore there was no obstacle to brewing an "oatmeal" stout, why only use only tiny quantities? Why not use more than that, as I understand the Maclay recipe did? (Jeff Renner gave information on that in a homebrewing forum posting from 2000 but I cannot find it now).

Legal reasons would suggest only a minimum would be used because there was a disincentive to use more but what would that have been after 1880? Maybe it worked like this: it became possible economically to use oats but they are hard to work with in the mash tun and do not promote clarity, hence the restriction to 1% or so. At the same time, it was perceived there was a marketing opportunity for a "strengthening" stout. It looks like brewers were trying to find a variation on the theme of stout, hence oatmeal stout, oyster stout, milk stout, to boost sales, indeed of a commodity which quickly was losing that status. Maybe it makes sense after all.



Gary Gillman said...

It still leaves the Irish distillers' practice I mentioned unanswered, but perhaps that has its own history and rationale. Yet, I am not really sure... Does Lloyd Hind talk about oatmeal stout mashbills I wonder?


Ron Pattinson said...

GAry, distillers did things differently to brewers, if only because different rules applied.

The Oatmeal Stout thing is clearly just a marketing ploy. Why so few oats in most Oat Stouts? Because they were being party-gyled with other Porters and Stouts.

Graham Wheeler said...

I have pondered this question about grist weights a number of times over the last twenty-five years or so, and have always come to the conclusion that it is safer to assume standard malt quarters for anything post 1880, certainly anything twentieth century.

One overpowering reason for this is that the Excise standard bushel for malt was 42lbs. The Gravity Book had to have the grist weight entered in standard quarters or standard bushels (or weight) because the taxation was based upon original gravity of the wort or the weight of the grist, whichever was greater. If the brewer did not meet at least 82lbs (or whatever it works out to be) per 336 lb he had a penalty to pay.

It would then seem pointless for a brewer to have used a different system for his Brewing Book, it would cause untold complications. Somewhere along the line it would have had to have been converted to standard quarters for Excise purposes, so that might as well be done from the start. In fact it would have been far more convenient to have weighed it in the first place.

Furthermore brewers invariably totalled up the grist quantities to determine extract efficiency. This in itself would be pointless if every number in the grist list meant a different thing. It would be chaos.

Measuring grain volumetrically is fairly imprecise too; it would depend upon the breed of barley for a start. Smaller grains settle closer. Imagine buying potatoes by the two-gallon bucket (which was done at one time apparently). I would expect a commercial brewer to demand a higher degree of precision than that with or without Excise interference.

In my youth, pre metrication, all corn, seed and potatoes came in 56lb bags. The standard grain bushel.

Some of the brewers may well have measured their grist volumetrically - it just needs the grist case above the mash tun to be calibrated - gauged - no big deal. However, at some point they would have had to convert their grist to standard malt quarters for the Gravity Book, and that is probably what those numbers were used for.

The argument is whether or not the Brewing Book also had its entries in standard malt quarters. It might well have been a legal requirement like the Gravity Book. Unfortunately I have no idea what the "Prescribed Form" for the Brewing Book was. In any case, a brewers who, in 1880, dealt exclusively in traditional quarters would soon get peed orf with the complication of it all and would have moved over to converting to standard malt quarters for entry in the Brewing Book. I know that I would have done.

I wonder what Excise did with all those Gravity Books. Burnt them I suppose.

Ron Pattinson said...

"in 1880, dealt exclusively in traditional quarters would soon get peed orf with the complication of it all and would have moved over to converting to standard malt quarters for entry in the Brewing Book."

Well, they had to convert all the volumes into standard 1055 barrels.

Jeff Renner said...

Here are a few thoughts about malted oats. I first used them to try to recreate a medieval recipe from notes in a Domesday book (not the original) about annual ale production at an English monastery. Details of the project can be found by googling appropriately, but the basics are that I made an unhopped (gruit would have been a good choice in retrospect)uncarbonated 1.096 ale using 50% malted oats.

This was about ten years ago, and malted oats were not available, so I malted them myself. I got a thick (about 10w40), sweet ale that was interesting, but I won't do it again. It took forever to clear.

But I was interested in malted oats as an ingredient, and soon after, a US importer began to bring in Fawcett malted oats. I got this note (which I think is what Gary is referring to) from James Fawcett of Fawcett & Sons, Maltsters
http://www.fawcett-maltsters.co.uk/welcom.htm , who are the only producers of this that I know:

"Oat malt laboratory worts are normally slightly hazy rather than clear. Oats are not normally low in protein and are quite difficult to modify from a protein viewpoint, which could well explain this. Our current stock gives values of 11.8 % total protein with an index of modification of 27.8%.

"As far as mash schedules are concerned we would suggest you ensure temperatures are between 63 degrees C and 68 degrees C during mashing in with a one hour minimum stand after mashing in a grist composed of 50% oat malt and 50% lager malt.

"You should aim at a liquor/grist ratio of between 2.5:1and 3:1.

"Oat malt needs very close mill settings to achieve an acceptable grist. For normal malts our standard mill setting is 62 thou top and 58 thou bottom- for oat malt we drastically reduce these settings to 48 thou top and 42 thou bottom. Certainly a point to watch to produce an optimal grist for mashing."

I also brewed a clone of Maclay Oatmeal Stout, which, according to Protz's Real Ale Almanac (5th ed.) uses a remarkable 22% malted oats. It turned out well, as did a brown ale using 15%.

The other brews I found in the book that used malted oats are Durham Brewery's Black Bishop, no amount specified, Malton Brewery's Pickwick's Porter, 3% oat malt, Freeminer Brewery's Deep Shaft Stout (no amount specified), Wadworth's Valentine's Oat Malt Ale, 11%, plus 6% pinhead oats (oatmeal), and Beartown Brewery's Polar Eclipse stout, 7%.

Graham Wheeler said...

Ron Pattinson said...
"Well, they had to convert all the volumes into standard 1055 barrels."

Well, yes, but the definition of a standard barrel is the minimum gravity that 84lbs of malt should produce.

In practice, I doubt if the brewer had to overly concern himself with standard barrels. Duty was paid on a linear sliding scale based on gravity.

In the 1944 Finance Act, brewers paid £7/0/7-1/2 up to 1.027, then five-shillings and twopence ha'penny for every degree above 1.027. Per barrel of course.

It explains why Whitbread porter was 1.027 at one point. It was the minimum amount of duty they could get away with.

It turns out that there was no "prescribed form" for the book that I will now call the Brewers Journal. He could put what he wanted in it, in whatever form he chose.

It is a case of me misunderstanding terminology. It seems that the 'Brewing Book' and the 'Gravity Book' were one and the same thing; it is the book that Excise supplied for recording their mandatory information. It seems that the terminology changed at some point. It was one of about half a dozen books, forms, and certificates that the brewer had to fill in on behalf of the Excise, and each had a "prescribed form".

As far as I can ascertain the Brewers' Journal was not one of them after all.

WHL said...

Might not the differences in weight be attributed to the amount of moisture held by each variety of malt? The roast and crystal being drier when they left the maltings would have been judged in relationship to volume of the base malt. During storage these colored malts would absorb more moisture and rise in weight towards the base volume to weight ratio.
I'm just basing this on my water additions to jasmine rice during particular times of the year, more water needed in the drier winter, less in the humid spring.

Cheers, Bill