More malt 1920-1939

Malt again. Apologies for being so repetitive. I'm making slow progress through "Brewing Science & Practice" by H. Lloyd Hind.

No jokes today. I can't think of anything funny to say about malt. If you can, let me know. There'll be lots more about malt in the months to come. Sounds like a threat, doesn't it?



Black malt
This was produced by roasting malt which had already been kilned in a revolving cylinder over gas jets. The aim was to roast the grains evenly and to avoid carbonising any. In practice, it was quite tricky to achieve. The carmelisation desired occurred at 445º F, but at just a slightly higher temperature, 480º F, carbonisation began.

Black malt was a standard ingredient in Stouts, but was also used in some other dark beers. Though not all brewers used black malt in their Stouts. Whitbread used chocolate malt and brown malt instead.


Roast Barley
When raw grain was roasted in a cylinder the result was roasted barley. This, like black malt, was mostly used to colour Stout. The flavour was not as rich as that of black malt, though it did aid head retention.


Amber malt
Two methods were used in the final stages of making amber malt, when the temperature was increased suddenly to darken its colour. One was roast it in a cylinder, similar to the way black malt was produced. The other was to use a kiln, raising its temperature by adding oak battens to the fire. This process gave the malt an empyreumatic (burnt) flavour considered superior to that of malt made using the cylinder method.

A small of diastatic activity was sometimes still present in amber malt. (Source: "Brewing Science & Practice" H. Lloyd Hind, 1943, page 275.) Diamber was a type of amber malt manufactured in such a way that it still retained most its diastatic power, around 26º Lintner.

There was a considerable variation in the colour of amber malt and some overlap between the darker versions and lighter types of brown malt.


Brown malt
As with amber malt, brown malt could be finished in a kiln or in a cylinder. The main differences with amber malt were a generally darker colour and a complete destruction of the diastase. Brown malt was falling out of favour, though London brewers still used it in their Porter and Stouts.


Crystal or caramel malt
Unlike roasted malts such as amber, brown and black, where kilned malt was heated in a revolving cylinder, crystal malt was made from green malt which had not been kilned. The malt was heated gradually to a temperature of 150º to 170º which liquefied the inside of the grain. As te process continued and the temperature rose higher, the grains began to roast. After two or three hours the grains were removed from the cylinder and as they cooled, the inside of the grains cystalised.

A far larger amount of sugar formed in grains, with maltose amounting for as much as 50% of its weight. Due to the presence of water in the grains, something similar to mashing, with the enzymes coverting starch to sugar, took place.

The colour of crystal malt varied even more than amber malt, as you can see in the table below.


Lager malt
There were two types of lager malt: pale and dark. The former, called Pilsen malt, had a colour of 2º Lovibond and a diastatic activity of 60-85º Litner. Dark Munich malt had a colour of 7-10º Lovibond and a diastatic activity of 30º Litner. Both types were made in Britain as well as being imported from the continent. Continental lager malts tended to have higher a nitrogen content and be less well-modified than British malts. The extract yielded was also slightly poorer.

Rather surprisingly, lager malt sometimes turns up in brewing logs. Not just in Lagers, but in British styles, too. As, at around 64/- a quarter, it was one of the most expensive malts, seeing it used in Mild is quite a shock.


Barclay Perkins September 11th 1936 XX, X
Amber____________3,68%
crystal____________4,82%
Dereham Californian__19,53%
Lager Kulmbacher____5,86%
Dereham MA________36,12%
Dereham MA NXOB___6,83%
Maize_____________12,86%
Garton No. 3 sugar____10,29%

Barclay Perkins had begun brewing lager in the 1920's and built a special brewhouse for that purpose. I suppose that explains why they would have lager malt lying around the brewery. Still odd to see it used in a Dark Mild, though.



Wheat malt
Because of the delicate nature of the grains, it was difficult to malt wheat without damaging them. As a consequence wheat malt tended to be under-modified and cause clarification and stability problems. For these reasons, it wasn't much used in Britain. Sometimes small amounts were added to the grist to aid head retention, something which still happens today with some Bitters.


Malted oats
Many Stouts contained a small proportion of malted oats. The amount was usually pretty small - often less than 1% of the grist. This wasn't just limited those beers called Oatmeal Stout. Most Barclay Perkins and Whitbread Stouts contained some oats. "Oat malt is used, mainly in oat malt stouts, for its flavour and nutritive properties." Given the miniscule amounts of oats employed, it's hard to see how they could add much flavour or nutrition.




Malt extract
Wort produced from very lightly cured malts was reduced in a vacuum pan to produce a concentrated syrup. Most malt extracts had a very high degree of diastatic activity, as much as 350º Lintner. They were used by brewers in a variety of ways. Of course, they were a source of fermentable material, but their high diastatic activity could also be of use in grists high in adjuncts.

Malt extract could be added either in the mash tun or in the kettle. Non-diastatic malt extract, added in the copper, aided head retention.