Wednesday, 29 October 2008

Mashing 1850-1880

No more jokes for a while. Not until I travel again. It's back to book extracts, I'm afraid. Today we're taking a look at mashing.

Fascinating subject, mashing. There are so many different ways to mash. I've been really intrigued by some of the older methods, especially the 3 or 4 mash approach. If I were still brewing, I think I'd give one of those a try. Even though it's more work than just a single one-step infusion mash.

The material today comes from Frank Faulkner's "The Art of Brewing", published in 1876. It's a collection of essays originally published in the Brewers' Journal.

Reading Faulkner's theories has got me wondering about the old three-mash method and whether or not that acted in a similar way to a step mash. One method described by Loftus ("The Brewer", 1856) gave these striking heats:

1st mash 178º F
2nd mash 184º F
3rd mash 188º F

Though, of course, the first wort had already been drained off before the temperature was raised. However, some wort would have been absorbed by the grains and so would be heated during the second mash.


Mashing
The mashing process and the theory behind it were evolving constantly during the 19th century. In 1800, London brewers mashed three times and sparged with relatively modest quantities of water. Picking up on techniques first employed in Scotland, by the middle of the 19th century, many were using a single mash and sparging with a much greater volume of water. Towards the end of the 1800's the simple step method, as described by Faulkner, where there was only one mash hot water was added part of the way through to raise the temperature, came into use.

There was more than one reason for the changes. Brewers were concerned with obtaining the best possible extract from their malt, but were also conscious of the need to speed up the process and to use as little energy as possible. Getting the desired proportion of different sugars in the wort - maltose and dextrin - later became equally important.


Faulkner's theories on mashing
During the mashing process, starch is converted to dextrine and then into sugar (maltose). By controlling the temperature and mashing time it was possible to control the proportion of dextrine and sugar (maltose) in the wort. How much dextrine was desirable, depended on the type of beer being brewed. Beers with a full palate, such as Stouts, and beers intended to be aged or exported, larger amounts of dextrine were benficial. Dextrine would not only add richness to the finished beer, but help to slow fermentation, something essential in a beer that would not be sold immediately. In beers intended to be fermented and sold quickly, relatively small amounts of dextrin were needed.

Worts with large amounts of detrine did not clear as easily nor ferment as readily.

Faulkner made specific mention of the difficulties of getting Stout right: "Much difficulty is experienced by many brewers in obtaining full tasted stouts, the error in the generality of processes being the excessive employment of saccharines; beyond this, the brown malt of a porter grist, besides having a different latent heat, has had its original strach so modified by the torrefication that it has undergone, that if ordinary heats are employed you are certain to procure from it a large proportion of actual sugar; and thus, from one cause or another, your stouts are highly saccharine and yet very deficient in palate fulness."

To get the required proportions of sugar (maltose) and dextrin, good quality malt, the right type of water and careful control of the mashing temperature were essential. Starch was converted into dextrin at one temperature and when the heat was increased dextrine was converted into sugar. By starting the mash at one temperature and then increasing it and leaving it to stand for a specific length of time, the conversion of dextrine into sugar could be controlled.

"You first of all use such a degree of heat as is capable of dissolving disatase, enabling it to convert starch into dextrine; and then you, by a simple addition of a further quantity of liquor at an increased temperature, enable the diastase to induce a further change - the conversion of dextrine into sugar."

Presumably this is why part of the way through the mash water hotter than that initially used was introduced via the underlet. This technique can be found in the logs of Whitbread and Fullers.

According to Faulkner, darker malts such as black and brown cooled mashing water less than paler malts and the same initial temperature could be obtained with a lower striking heat. A thicker mash required a higher striking heat (pretty obvious, as there was less water to heat the malt) and gave a less clear wort. A thin mash produced a clearer wort, but a worse extract.

This was Faulkner's preferred method of mashing when using an external Steel's masher:

"I am in favour of using two barrels of liquor per quarter when through a mixing machine at about 168º, which gives me an initial temperature of of 150º, rising to 156º or 158º before setting tap, and a tap gravity of 33º per barrel [og 1090º]. Now such a mash gives you, I believe, dextrine and sugar in equal proportions, with a satisfactory malt. If the malt is imperfectly malted, your dextrine is in greater proportion, since the diastase has had more work to effect, and you must adopt either some special kind of fermentation to allow of this dextrine being decomposed, or you may keep your wort for some time at a temperature of 170º after it runs from the mash tun, to allow of the diastase exerting its converting power on the excess of dextrine before the power of this converting agent is destroyed by the boiling temperature in the copper, or you may increase the proportion of sugar in your worts by the addition of saccharine."
As we'll see in the next chapter [this is book stuff, "next chapter" doesn't apply here] , "dextrine and sugar in equal proportions" is a bit wide of the mark. The ratio of maltose to dextrin was at best 3:1.

Faulkner's recommendation was somewhat different for breweries equipped with an internal rake masher:

"With rake machinery you mash in with about one and a-half-barrels per quarter at some 162º, and you allow this mixture to stand some thre-quarters of an hour; and then a secondary quantity of liquor, at a much higher temperature than the first, is forced under the false bottom and mixed in by the machinery. . . . If a dextrine beer is required - and I had better remark that it never is wanted in a small brewery - you take a sufficient quantity of second flow liquor at a rate of half a barrel per quarter to bring up the heat of the mash to 156º or 158º, while you stand some hour and a quarter after final mixing is finished, and then, on setting tap, bring the wort to the boil as soon as possible, to destroy the converting agent, and prevent the proportion of constituents being altered. . . .If, on the other hand, a saccharine beer is wanted, your second flow of liquor is taken at such a heat that the initial temperature is raised to 165º or 170º . . . . Time is another important feature. The longer you allow the mash to stand at this elevated temperature the more sugar you will obtain; but you must, on no account, stand so long as to allow cooling down taking place."

With the "saccharine beer" method, it was important to ensure all the starch had been converted before applying the higher temperature water, otherwise starch might end up in the wort. Iodine was used to test the wort for starch as it was run off. If it were present, the wort was kept at 170º for an hour in the copper before being boiled.

Faulkner recommended sparging in the same way, no matter which type of mash had been employed. The sparging water needed to be warm enough to convert any remaining dextrine in the cooler upper portion of the mash to maltose, but not so hot as to dissolve unconverted starch nor destroy the diastase. If the temperature fell too low, lactic acid was likely to form. To satisfy all these considerations, 176º F was the perfect temperature.

9 comments:

Baums said...

"You first of all use such a degree of heat as is capable of dissolving disatase, enabling it to convert starch into dextrine; and then you, by a simple addition of a further quantity of liquor at an increased temperature, enable the diastase to induce a further change - the conversion of dextrine into sugar."

You may eventually need some definitions to avoid serious confusion. For instance, a modern tendency is to use the word "dextrins" when one is really speaking of "limit dextrins" (certain polysaccharides that the enzymes in question are incapable of reducing to sugars--at any temperature). Modern readers may assume Faulkner is referring to these when he speaks of "dextrine," and his statements will then make no sense.

Perhaps Faulkner is referring to something else, such as soluble starch (though that doesn't make much sense either). Another possibility is that the theory he presents is flawed.

Kristen England said...

I've always seen dextrin referred to as 'sugar'. Meaning they use them interchangeably.

A lot of these mash types pose problems in that they are extremely high temperature. The amount of beta limit dextrins would be massive. Ive tried doing this type of mash as an experiment just as described. Two big problems. 1) there is a very big chill haze in that not all the starches are converted sufficiently. 2) The beer has very poor 'shelf' stability. There are so many starches left in solution for the nasties to work on.

Having said that, many of the brewing manuals mention mashing high for stouts and beers to mature as it develops the 'aged' flavor better. Makes a lot of sense in that Brett can chew up these dextrins were yeast and most nasties can't.

Graham Wheeler said...

Faulkner seems to have got it the wrong way round. The higher temperature of around 77°C (170F) favours alpha-amylase - starch to dextrin. At this temperature the beta-amylase, responsible for converting dextrin to simpler sugars, saccharification, has been denatured - knackered. Faulkner, or whoever, has taken a standard procedure and not really understood why it was (still is, in fact) done.

That is the problem with many of these Victorian brewing books; very often the science is wrong, even by the standards of the day. Many of these authors were not brewers at all, but self-appointed experts on everything in particular, or people from other branches of science that decided to cash in or elevate their status.

It isn't helped by the high degree of plagiarism endemic in those days, particularly in brewing books. I have several books with the same verbatim passages in them, a couple in particular as much as 54 years apart.

To get the best from these books you need to already have a good knowledge of brewing and a good knowledge of brewing history, otherwise it is easy to get blown off course.

I return to this blog frequently because I learn as much from it than R.P himself. Often, however, I draw different conclusions than R.P. does.

Ron Pattinson said...

Graham, couldn't agree with you more. You have to be very careful with these books. That's why I've made it clear that this is what Faulkner was saying, not necessarily fact.

Yep, there's loads of plagiarism. Even Loftus, whose books are some of the more reliable, has lifted bits from Tizzard.

I've included Tizzard's theories, not because I think they are correct, but because brewers of the period would have been exposed to them. His book was based on articles printed in the Brewer's Journal. And I've seen brewing logs - Fuller's for example - where they were adding hotter water through the underlet partway through the mash.

One of the reasons I publish large amounts of old material is so people can draw their own conclusions. The reactions I get are also very useful in forming my own ideas.

Ron Pattinson said...

Before I forget, I'll be posting more about maltose and dextrin soon. Material from later, hopefully more reliable books: "The Principles and Science of Brewing" by Sykes and Ling and "Manual of Brewing" by Egbert G. Hooper. I'd like to hope the latter is more accurate, as it was the text book for the City and Guilds Technical Brewing exam.

Graham Wheeler said...

The books do not have to be accurate to still have value. There is still, usually, good information to be gleaned from them, it is just a case of reading between the lines. Some of the "pretenders" did produce good, informative books.

I have not been able to find any evidence that William Ellis (London and Country Brewer), for example, ever had a large commercial brewery, although he claimed to. By the time the first edition of London and Country brewer was published, Ellis had been a farmer at Little Gaddesden, Herts, for at least 50 years. All farmers brewed in those days, of course, but that is not "a large concern", as he put it. Ellis seems to have been a professional writer; he wrote books on other subjects, mostly farming but also sweet manufacture, of all things. The fact that he was not really a brewer may explain why the early editions of his brewing books were published anonymously; none of his other books were.

Pretender or not, his book is still better than most of the period.

Graham Wheeler said...

The books do not have to be accurate to still have value. There is still, usually, good information to be gleaned from them, it is just a case of reading between the lines. Some of the "pretenders" did produce good, informative books.

I have not been able to find any evidence that William Ellis (London and Country Brewer), for example, ever had a large commercial brewery, although he claimed to. By the time the first edition of London and Country brewer was published, Ellis had been a farmer at Little Gaddesden, Herts, for at least 50 years. All farmers brewed in those days, of course, but that is not "a large concern", as he put it. Ellis seems to have been a professional writer; he wrote books on other subjects, mostly farming but also sweet manufacture, of all things. The fact that he was not really a brewer may explain why the early editions of his brewing books were published anonymously; none of his other books were.

Pretender or not, his book is still better than most of the period.

Andrew Elliott said...

He mentions fairly high "striking heats". Perhaps these are the temperature of the hot liquor rather than the actual mash, thus the mash temperature would end up lower.

Ron, is this correct to assume, or do sources seem to indicate this is mash temperature?

Ron Pattinson said...

Andrew, striking heat is indeed the heat of the water, not the initial heat of the mash.