Here's some more about mashing. In particular, the method where the temperature of the mash is raised part of the way through.
My source today is, I believe, a bit more reliable than Faulkner. It's "Principles & Practice of Brewing" by Walter J. Sykes & Arthur R. Ling, published in 1907. I like it anyway. If only because it has one of the first mentions of brettanomyces in a brewing manual (it was only discovered in 1904).
I've not looked at the theoretical part of the book yet. Maybe they'll prove to be as misguided as Faulkner. They are at least talking about different kinds of dextrin.
In well-equipped breweries, water for mashing was heated in the hot-liquor back. Usual practice was to boil the water the evening before before brewing for 15 minutes. It cooled overnight and needed to be reheated to get to the correct mashing temperature. Boiling ensured that the water was sterile. Most water contained chalk, which precipitated out when boiled, taking with it any organic matter in the water to the bottom of the back. To stop this getting into the mash, the opening through which the water was drawn off was always a few inches above the bottom.
If the water was hardened with gypsum or other salts, it was added while the water was being boiled.
The mash tun was warmed with hot water or steam before mashing started.
The initial temperature, that is the temperature of the mash after the grain had been mixed together, varied depending on the variety of malt being used and the type of beer required. Initial heats varied between 145º F and 145º F. The striking heat, that is the temperature of the water before it was mixed with the malt, was determined by taking into account a number of factors, such as the temperature of the malt and the volume of water per quarter of malt. Brewing manuals contained tables to allow brewers to easily calculate the necessary striking heat.
"Beers intended for storage are, as a rule, brewed from pale malts. These are mashed at a somewhat higher degree of temperature than high-dried malts, for we require, in this class of beers, a fairly large quantity of those dextrins which ferment very slowly, and which, since they provide for a long, slow, continued fermentation, keep the ale (through the period of its storage) charged with gas. High-dried malts are mashed at a somewhat lower temperature, since the beers produced from them are quickly consumed, and here we require a wort which contains large quantities and of those maltodextrins which give fulness and sweetness to the beer. Between these two types of beer, which may be seen as extremes, there are many other intermediate ones that are brewed to suit the particular wants of different neighbourhoods."
As most malt contained more than enough diastase, a temperature high enough to destroy some of it was used. If all the diastase remained active, too much maltose would be produced, resulting in a thin-bodied beer.
Despite all the theory, experience still played a big part. "A delicate appreciation of the right initial heat to be employed with different malts to produce different beers of the required character is only to be obtained by actual experience and is one of those things for which hard and fast rules cannot be laid down."
If the mash tun was fitted with a Steel's masher, hot water, at the correct striking heat, was run through it into the mash tun until it just covered the false bottom. Then grist and water were put through the masher which mixed them together and pushed them into the tun. Brewers learned to be able judge if the proportions were right by observing consistency of the stream as it tumbled into the tun. If it were not quite right, the flow of grain and water could be adjusted accordingly. The Steel's masher was very efficient as it heated the grain uniformly. Which is doubtless one of the reasons it is still in use today.
If the tun had an internal rake masher, the procedure was somewhat different. First a little more water than actually required for the mash, at a slightly higher temperature than the striking heat, was run into the mash tun. When the tun had warmed up, the taps were opened to flush the spend pipes. If the water were still too hot, the masher was switched on and after a few revolutions it would have cooled to the right temperature. The tun was closed and the grain dropped quickly into the water. The rakes were kept turning as the malt was being added at a little less than on revolution per minute. After all the malt had been added, the rakes were kept turning for a further 15 minutes until the grain and water had mixed to an even constituency. The disadvantage of this method was that not all the grain was heated to the same temperature, as it was with an external masher.
The total amount of water needed to brew a beer of a certain gravity was calculated taking into account the water that would be absorbed by the malt (28 to 30 gallons per quarter) and the hops (53 gallons per 100 pounds) and would be lost through evaporation during the boil, cooling and fermentation (around 30%). The amount of water used in the mash was between 1.5 and 2.5 barrels per quarter of malt. As the total amount of water was constant, the thicker the mash, the more water could be used when sparging. A thick mash and generous sparge was the best way of getting the greatest extract from the grain.
After the mash had stood for about 15 minutes, more water, at a temperature 10º to 12º F higher than the striking heat, was added via the underlet. If the tun had a rake masher, this was given 4 revolutions to mix the new water evenly through the mash. In tuns with an external masher, the water was added very slowly so that it could gradually spread through the mash.
There were two reasons for raising the temperature of the mash: to produce a greater proportion of higher maltodextrins; to compensate for poor quality malt. When doing the former, the temperature of the mash was raised to 158º F or more in order to check diastatic activity. The time standing was also usually reduced to just an hour. When compensating for poor malt, the initial heat was very low - 140º to 145º F. After half an hour, the temperature of the mash was gradually raised to 155º F and then left to stand until all the starch had been converted. The mash could be heated either by adding extra water through the underlet or by the use of a heating device within the mash tune, such as a steam coil.
The mash was left to stand until all the starch had been converted. Samples of wort were taken at regular intervals and tested with iodine. As soon as no starch was detected, the taps were opened and the wort run off.
Some breweries still performed a second mash. Around half the brew length was drawn from the first mash and sparge, then a further 1.5 barrels of water per quarter were added to the grains in the mash tun. It was left to stand for 1.5 hours, after which the wort was drawn off and a second sparge performed. While some brewers though this method gave a better yield, many considered it a waste of time. In rare cases, even a third mash was performed.
There's a good example in the Fuller's 1910 brewing log of a mash heated by means of the underlet.
March 14th 1910 Fuller's AK
Ingredients: 27 qtrs pale malt, 2 qtrs flaked maize, 7 qtrs sugar
65 barrels water @ 164º F; initial heat 150º F; mashed 1 hour, stood 25 minutes
15 barrels via underlet @ 175º F; raised temperature of mash to 155º F; stood 80 minutes
sparged with 114 barrels of water at 168º F and 165º F
Using 2.25 barrels of water per quarter of grain, this was a relatively thin mash.
The mashing scheme was quite different for their darker beers:
August 10th 1910 Fuller's Brown Stout and Porter
Ingredients: 35.5 qtrs pale malt, 7 qtrs brown malt, 3.5 qtrs black malt, 2 qtrs flaked maize, 24 qtrs sugar
103 barrels water @ 155º F; initial heat 146º F; mashed 1 hour, stood 20 minutes
15 barrels via underlet @ 175º F; raised temperature of mash to 150º F; stood 100 minutes
sparged with 199 barrels of water at 170º F and 180º F
The initial heat was 4º F lower than for the AK and the mash was left to stand for 20 minutes longer. The temperature of the sparging water was, however, a good it higher.
Bass brewery to close - *Molson Coors have confirmed that their Burton (South) plant is to close in September 2017.* The brewery is perhaps better known as the old Bass brewery. ...
3 hours ago