Recently, I decided to try to make my own air-dried wheat malt. Now why would I be interested in doing that? Isn’t that a lot of work? Yes, it was. I won't pretend otherwise.
The reason I would want to try that: history, of course!
A Very Brief History of Malt Kilning
In the old days, breweries by necessity would make their own malt. However, the kilning was relatively uneven, and fuels were not very clean tasting: common fuels included beechwood, oak, straw, and what appeared to be the fuel of last resort, peat. These fuels often left flavors that often were seen as unpalatable & would have to be aged out of the beer. Direct fired malts made in this way usually would be amber to brown in color, contained diastatic power, & would have been used at 100% quantity for their respective beer. [1] In a nutshell, that's how you got "brown ale", "amber ale", "pale ale" in the 18th century. Those definitions changed significantly over the next 200 years, but I digress.
Pale malts could be made using these fuels, using methods similar to that of preserving meats, but these malts also would take on a smoky flavor: think the flavor profile of a Lichtenhainer or a Pivo Grodiskie, or as it turns out, also the flavor profile of Berliner Weisse during the 19th century. [2] The total lack of smoky, pale beers in British brewing seems to imply the Brits especially didn't care for this flavor profile.
It was not until the invention of coke, made from heating coal in the absence of air (a process called coking), towards the end of the 17th century that smoke-free, direct-kilned pale malts could be made. However these pale malts were quite expensive, darker malts were used for cheap beers made for the masses: this was the case with English Porter. The invention and adoption of the hydrometer showed that pale malt had a much higher extract efficiency, which offset its higher cost. [3] Before long, every beer went pale: including Strong Scotch Ale, something we think of as low hopped, dark, and syrupy sweet. [4]
However, “white” beers existed far before the invention of modern pale malt. These beers, including Berliner Weisse, Belgian Witbier, & Lambic originally were made with air-dried malt, Luftmaltz in German, literally dried in the drafty lofts of barns, or by the sun. This kind of malt has a slightly more delicate character, & a slightly higher moisture content than kilned malt, which necessitates using it faster. That’s on top of it being significantly more difficult to make at scale, susceptible to pests, or molding before it can dry. [5]
Can’t You Just Buy it?
Sort of. I’ve seen a couple of maltsters offer air dried barley: Sugar Creek from Indiana, and Mecca Grade from Oregon. I’ve bought each and had good results.
However, I was after something very specific: I wanted to create an 18th century Berliner Weisse, taking it back to the time it was all air dried [6], which meant that I also needed malted wheat, so I had to make it myself.
One other advantage: You can undermodify the malt on purpose & make it more suitable for a step / decoction mash regimen, which of course I fully intended to do.
Making Your Own Malted Wheat
Source: BYO
First off, I’d like to say thanks to BYO for the great article on making your own malt. It provided some great guidelines.I opted to malt in a large mason jar. The article says ideally it should be in a shallow tray, but I wanted something impenetrable to potential pests, so I got “sprouting lids” from Amazon.
The first stage is steeping: I started with 2 lbs of wheat, not realizing that you will actually end up with less weight at the end of the process due to the fuel that gets used up in the kernel during the malting process. I rinsed the raw wheat berries in a colander, and then transferred them to a large mason jar. I covered the wheat with distilled water and let it steep for 18 hours. Distilled water is recommended if you smoke the malt to dry it, because the smoke can react with chlorine in tap water and create phenolic off flavors.
The next day, I drained the wheat in the colander thoroughly, and returned it to the jar. At this point the wheat is hydrated, and needs to be rinsed every 12 hours. If the grain is laid out, it can simply be mixed up and misted, but extra care is needed to make sure it doesn’t stay too wet and end up moldy.
Twice a day, I repeated the process of rinsing the wheat with distilled water and then draining it thoroughly in the colander before returning it to the jar. After several days, the shoots had reached 1/2 to 3/4 the kernel length. Since I was especially wanting to err on the side of under modified, I decided to begin the drying process.
To the Dehydration Station
Now, although traditionally Luftmaltz would be made with the wind or the sun, this would take too long and leave it open to pests, so I decided to use a food dehydrator. I created makeshift racks out of aluminum foil to hold the sprouted grain and loaded it up. Even with five trays, I was at capacity with 2 lbs of grain. You definitely want something that breathes better, the aluminum foil was far from ideal. They make mesh mats for this sort of purpose, which I'll try out next time.
I dried the grain on low and periodically weighed it to determine how much moisture was left. The BYO article indicated you should end up with 13 oz of malt for every 16 oz of unmalted grain. However, the article is specifically for barley, & I was not able to get the malted wheat down to the target weight, but it was very dry, so I decided to go with it anyway.
As for the shoots, the article gives some methods to help get rid of them, they blow away quite easily. You can rub the shoots off but that would be tedious. Historically, Belgian Witbier was mashed with the shoots, so I decided there was historical precedent to be lazy & leave it alone.
In the future, I intend to try cold smoking home made malt before finishing the drying process in the food dehydrator, likely for a 19th century Berliner Weisse variant.
[1] https://barclayperkins.blogspot.com/2008/08/brown-malt.html
[2] https://barclayperkins.blogspot.com/2022/02/berliner-weisse-part-four.html
[3] https://barclayperkins.blogspot.com/2012/12/pale-beer.html
[4] https://barclayperkins.blogspot.com/2019/07/scotch-ale-in-late-19th-century.html
[5] https://zythophile.co.uk/2009/11/26/burton-not-the-first-place-in-the-world-to-brew-pale-beers/
[6] https://barclayperkins.blogspot.com/2022/02/berliner-weisse-part-one.html