Thursday 4 September 2008

Malt circa 1900

Life's full of surprises. That's what makes it so much fun. Today's came when I looked at malting techniques from around 1900.

You probably remember last week's post about brown malt. I showed how claims that 18th century Porter was smoked weren't backed up by contemporary accounts. I'm now going to tell you the exact opposite about late 19th century brown malt.

I've only got one source for the information at the moment, so the text below is still provisional. But that source is the authoratative "Principles & Practice of Brewing" by Walter J. Sykes & Arthur R. Ling, 1907 (pages 456 - 475). For the moment, I'll assume they did know what they were talking about.

So was the brown malt used in Porter smoked? Yes and no. It depends which period you're talking about.

At least I think I've worked out why old-fashioned brown malt still had diastatic power. Anyone know how brown malt is kilned today?

These are the different types of malt that were manufactured in Britain around 1900:

White malt. Made from the very best and palest malt and dried at a low temperature. This type of malt was no longer made very often.

Pale malt. Also manufactured from top-quality barley but dried at a higher temperature than white malt.

High-dried malt. Kilned at a much higher temperature than pale malt and sometimes made from lower-quality barley.

Amber malt. Similar to high-dried, but kilned at a higher temperature. Sometimes wood was added to the furnace at the end of the process.

Imperial malt. Was manufactured in a similar way to amber malt, but at the very end of the process oak or beech wood was added to the furnace to raise the temperature from 240 to 270º F.

Crystal malt. Dried in a rotating wire cylinder at a very high temperature.

Brown malt. Not left on the withering floor as long as other malt and spread in the drying kiln no more than 1.5 inches (37.5 mm) thick. Initially the heat was moderate, but when all the moisture in the malt was gone, the heat was suddenly increased by adding oak or beech wood to the fire. The sudden heat caused the grains to swell by 25%. The smoke from the wood gave the finished malt a smoky flavour.

Black malt. Roasted like coffee and often made from inferior quality malt, though use of a better quality malt produced a better end result. The final colour was not black, but a chocolate brown. Because it was readily absorbed water, it didn't store well.

The deliberate addition of wood to create smoke and to allowing it to come into contact with the malt is very different from 18th century practice, where avery attempt was made to prevent this happening. Though with the much reduced proportion of brown malt being used in Porter and Stout - a maximum of 20% - the smoky effect would have been much less than in a beer made from 100% brown malt.

Based on the descriptions of their manufacture, imperial and sometimes amber malt would have also had a degree of smokiness.

Either coke or anthracite was used as fuel for the drying kiln. The fumes from the fire passed over the malt, flavouring it. Most brewers believed that this was beneficial and gave the finished malt a better flavour.

The presence of diastase in older forms of brown malt is explained by the way it was produced. Diastase is much more sensitive to heat when moist. By first removing all the moisture from the malt at a low temperature, the diastase was not damaged as much by the finishing high heat.

Other coloured malts were produced in a very different way. To get the desired aroma in the malt, it needed to be heated to 160º F while it still had a moisture content of between 12 and 15%. If the moisture content was below 7 or 8%, the aromas would not be formed and all.

The yield from one quarter of malt was between 75 and 98 pounds of extract.

Malting techniques
After centuries of being constructed in essentially the same way, malt houses were beginning to change. The traditional method was to spread malt thinly upon the floor and to pass cool air over it to start germination. The barley needed to be regularly turned, a very labour intensive process.

Around 1880 a new mechanical method called drum pneumatic malting was developed. Instead of being spread on the floor, barley was placed in a slowly rotating drum through which cold, moist air circulated. The new method had the advantages of taking up far less space, being less labour-intensive and allowing the maltster to more accurately control the temperature of the germinating barley.

As usual with new developments, not everyone was convinced it produced as good results. Many brewers and maltsters were convinced of the superiority of floor-malted grain. Come to think of it, many still are, more than a century later.


  1. I use Crisp's Amber and Brown malts. Amber is made from pale malt and is classified as a very low color 'chocolate' malt. Brown is made from the green malt, just like Crystal malt, and is thought to be a low colored crystal malt. Both are drum roasted, the latter is 'stewed' and the former is not.

  2. I detest beer blogs as you probably already know. I like to take the piss out of certain members of the beer blog community. But, I will say that this blog, or whatever you call it is excellent. The amount of worthwhile information is incredible. Love it!

    Wurst aka Whorst

  3. Another great post. I'm actually wondering if the info above about black malt partly answers my question yesterday about chocolate malt. If what was called 'black malt' was really only a brown colour then perhaps today's chocolate malts are a better approximation of late 19th century 'black' malts than today's black malts - which really are jet black, both to look at, and in their effect on the beer.

  4. Kristen,

    just for clarity, in regards to modern practices, amber malt is made using a general malting process -- green malt is kilned, then roasted a bit longer than pale to develop color, whereas brown malt skips the kilning and goes straight from green malt to roasting?

    Ron mentions that he thinks the presence if diastase in the old brown malt is due to the malting regime.. reducing moisture then roasting [for a shorter period of time]. so perhaps what Kristen mentions, the differences between modern amber malt and brown malt, points to the possibility that modern brown malt is roasted while moist, and thus for a longer period of time at the higher temperature (but moisture at the high temp being more the issue?).

    i'm loving this blog... it has me digging deeper into brewing than i ever have... i like bjcp guidelines because they give me an idea for the beers i brew, and how to brew beers from particular cultures, but your blog and research also teaches me to interpret those guidelines and question them and encourages my own position on "anti-style"... brew what i want.

  5. Does Crisp's brown malt have diastatic power? I ask because I have just purchased some for the express purpose of experimentation to find out on my own, but would welcome dissuasion from more knowledgeable parties.

  6. Sorry, it was not my intention to leave an anonymous post. My name is Mark.

  7. On a complete aside, I'm enjoying the beer labels that are accompanying these posts -- packaging design from the age before computers is just so cool.

  8. Bailey, I love old labels, too. I worry these posts will look too dull without the colour they provide.

  9. Have you a label from Wm. Oliver & Sons, Ltd., of Worcestershire?

    I've never seen an original, but saw a .gif online once -- and neglected to download it at the time.

  10. Mark, never seen an Oliver's label. I'll keep my eyes open for one.

  11. Thank you, I'd certainly appreciate that.