Thursday, 30 October 2008

Mashing 1880 - 1914

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.



Mashing
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.

13 comments:

Kristen England said...

Ive found the mash thickness of Fullers to be nearly comparable to todays mashes.

They nearly always equal 1 quart/lb. Thats actually a tight mash. Most of the current UK breweries ive talked to use about 1.25-1.3 for single infusions.

Graham Wheeler said...

1907 is fairly early to mention water treatment too.

He is still using the term diastase, which indicates that at that time they still thought that just one enzyme was responsible, but today we know that it is a group of enzymes.

The procedure, however, probably the result of a century of empirical experience, shows that they were aware that there was more than one side to that particular coin.

The lower temperature favours-beta amylase and the higher temperature favours alpha-amylase. I doubt if the higher temperature is enough to completely destroy the beta amylase, although it is getting close to its limit. The thing is that they work at different speeds relative to one another at differing temperatures.

I doubt if they would run off immediately starch end-point is reached. Starch end-point can be reached in about 15 minutes, but saccharification takes a lot longer. Traditionally they measured starch end-point after 30 minutes at the lower temperature, and raised the temperature to the higher temperature if it was okay, but I don't really know what that achieved.

The thirty minutes at 145 and then raising to 155 for the remainder of the mash was standard practice from Victorian times up to almost the present day. I wouldn't mind betting that traditional brewers like Hook Norton or Palmers, still do it.

I use a similar technique, underletting, in my home brewing, mainly because it gives easier control of temperature to start off at a lower heat and raise it to the desired temperature. Less hit and miss than relying on strike-heat calculations being right and destroying some of the enzymes in the process.

I am a bit bemused by the long "mashing" times employed by Fullers. In old-time brewerspeak, mashing referred to the physical stirring, either by blokes with oars or by the Armstrong Rakes or Porcupines when fitted. Usually fifteen to thirty minutes was deemed sufficient. Today we would refer to the stand as mashing.

Ron Pattinson said...

Graham, Faulkner mentioned water treatment, too.

They specifically say that getting the temperatures right was a matter of experience.

Just checked the theoretical section. They suspected more than one anzyme was active, specifically because of the effect of different temperatures.

Having quickly looked at Fullers and Whitbread logs, both seem to have used the underletting technique for a very long time. Fullers seem to have dropped in sometime in the 1960's. They were still doing it in 1962, but not in 1969, though the log form still had a space to fill it in.

John Keeling was bemused by the one hour mashing time, too. His only explanation, was they couldn't have been using a Steel's masher. But the old mash tun preserved at Fuller's does have an external masher. Using that, mashing shouldn't have taken longer than 20 minutes. Thw Whitbread logs show 30 minutes mashing.

Graham Wheeler said...

I have been giving that some thought. I have come to the conclusion that the mashing times probably included the time that the steele's pre-masher was in operation. It is the only explanation that makes sense to me at the moment.

The rakes were still fitted to mash tuns that were equipped with Steele's, but two or three revolutions of the rakes was deemed sufficient, basically to level out, and homogenise(?) the grain bed after the Steele's had finished. Obviously the pre-masher would dump the grain into a pile below its outlet.

Most traditional breweries, with traditional mash tuns still underlet for various reasons. Sometimes to raise the temperature in emergencies, but usually to raise the temperature to 76°C after the mash was finished, just before sparging and run-off.

Gales were still doing that when I spent a brewing day with them about 20 years ago.

Jim Johanssen said...

On underleting.
My theory is it was prophylactic, to reset the grain bed to prevent a stuck mash, because a long mash may cause the grain bed to set too tight for lautering. Floating the grain bed allowed the grain bed to be reset looser.
OR
2) Floating the grain bed provides better mixing of mash with the rakes.
4) May also be to clear the pipes under the mash tun out.
5) It could be also that the easiest way to get water into the mash tun was from the pipes going to the underback. Why have extra equipment in the brewhouse?

Remember the Decoction mashing also had long mash times too! I still think it has to do with the some issue with the malt.

Just Beer For Your Thoughts
Cheers
Jim

Andrew Elliott said...

The brewer's star on Ratliffe's Jumbo Stout mat is interesting... I had always thought that was generally a Czech/German thing. I guess it was a bit more widespread than that.

Cool!

Ron Pattinson said...

Jim, I'm afraid that I haven't included everything from the manuals. It would answer some of your questions.

I didn't bother with the bits about a stuck mash, as I thought it was outside my scope. Underletting wasn't mentioned in connection with a stuck mash. Return worts and over-ground malt were.

The pipes were cleaned out with the hot water that was put in the tun to warm it.

The manuals and logs show the same thing: water added through the underlet heated the mash. Why they did this is another question.

They had two options for adding water to the mash: the sparger and the underlet. There must be a reason why they wanted to be able to introduce water from both above and below. Both sparger and underlet co-existed for a very long time.

Breweries without rakes still had underlets. Fuller's definitely were using an underlet without rakes. In one old manual it describes adding water via the underlet with and without rakes.

There is mention in the manuals of mashing techniques for poor-quality malt. What I've described is for well-modified, good quality malt.

Great to be able to discuss this stuff. I tried with Dolores earlier, but her eyes glazed over before I got past underl

Ron Pattinson said...

Andrew, don't know it that's a brewer's star or just a six-pointed star.

Graham Wheeler said...

The reason for underletting is that it is the only way to raise the temperature of the bed in an emergency. Hot water rises, so it makes sense to introduce hot water at the bottom.

Underletting will also raise the grain bed off the false bottom, and will thus, if you are lucky, recover from a set mash. Commercial brewers, brewing the same stuff day in and day out, are very unlikely to suffer a set mash though.

One of the reasons why the Fullers long mash times intrigued me, was because it is easy to over-stir a mash, waterlog it, and cause it to sink and set. A mash should float if a set mash is to be avoided, thus some entrained air is necessary. Over-stirring expels that air. I know that sounds daft!

Jim Johanssen said...

Ron - I think you hit he reason they underlet, it floats the mash making it easy to manually mix opposed to using a sparge arm that would at water on top of the mash. The gravity would help breakup the mash as the brewers stirred it.

Graham - I’m trying to figure out why the brewer’s do some of these technics that they do. The have some reason although sometimes a bit strange or wrong, but that is what makes brewing so fun one can do what one wants.

The Steele’s Masher is new to me, I have not seen one used at brewery or had a brewer say much about them. If a brewery has a Steele’s masher then mash rakes are not as important to have for mash mixing. I understand there use, but could the mash be harder to lauter because of the screw crushing the grain?
Or - is the grain bed not formed well for a good efficient lautering?

Cheers
Jim

Ron Pattinson said...

Fuller's new mash tuns have a Steel's masher, as does the preserved old one. The main advantage seems to be that its possible to ensure that all the grain is heated to the same temperature.

Graham Wheeler said...

Don't know if this stuff gets read after Ron has moved onto something else, but here goes anyway. One of the advantages of the Steele's masher, or any form of pre-masher, is that it gives more reliable and thorough wetting of the malt avoiding dry clumps, which could not be assured by tipping sacks of malt in the tun, even with enthusiastic stirring.

The major advantage, however, is that it reduces the critical differential between strike heat and initial heat. Obviously, with a typical strike heat in the mid 70s Celsius, a lot of grain has to be dumped into the mash tun before the temperature falls to a safe, non-enzyme-destroying, level. Obviously, some of the enzymes get denatured in this process.

A pre-masher eliminates that by enabling the grist to be wetted with liquor much closer to initial heat. It also eliminates the major reason for the aforementioned two-temperature mash, and enables the brewer to mash at a single temperature of 65/66°C, the average of the two temperatures in the underlet method.

You might even find that the introduction of the Steele's coincided with the demise of 145/155 mashing, or at least the beginning of the demise, brewers being sluggish creatures when it comes to change.

Ron Pattinson said...

Graham, Sykes and Ling say exactly the same thing: externaml mashers mix better and give a more even temperature. Come to think of it, John Keeling at Fuller's said the much the same, too.