Malting Barley
Typically when you brew beer, you buy malted barley, but I wanted to dig deeper into the process so I gave malting a try. At a conceptual level, malting is ’tricking’ living barley seeds into sprouting, starting in motion the biochemical processes that unlock their carbohydrate reserves– then halting this process before the barley consumes those reserves.
Jon Palmer has a more technical description of what “malting” is-- at a simple level it’s “tricking” living barley seeds into sprouting, starting in motion the biochemical processes that unlock their carbohydrate reserves– then halting this process before the barley consumes those reserves.
Consider this a brief summary-with-photos of malting at home without specialized equipment. There’s very little practical reason to do this– you can buy a wide variety of high-quality malted grains for brewing, and it seems moderately difficult and labor-intensive to do well yourself– but it was still interesting to me, as part of working every step of brewing back to the basics:
- I started with organically-grown 2-row barley sold for planting (a bit pricey per pound, but easy to buy in small quantities and known to be tested for germination)
- I steeped the barley by alternately soaking it in water and letting it drain until it hit roughly 45% moisture content
- I germinated the barley by spreading it on trays, wrapped in trash bags to keep in the moisture and kept in a temperature-controlled box.
- The grain quickly sprouted rootlets, which continued to grow over the next 4-5 days
- Once or twice a day I stirred the grains to ensure even distribution of moisture and temperature and to prevent the rootlets from getting too entangled, and sliced open a few grains to monitor the internal growth of the acrospire (first sprout). When the acrospires (the first sprouts of a germinating seed) were most of the length of most grains (but before they had burst through the husks) the barley should have gone through the major physical and biochemical changes necessary for brewing.
- I dried the grain in two stages in a dehydrator (110F until below 10% moisture, then 150F until below 6% moisture, based on periodically weighing a sample of the barley compared to its original weight) to halt germination, and then sieved off the withered rootlets.
- Finally, I kilned (roasted) the grain at 180F for about 4 hours, to develop a reasonable flavor for beer (this is roughly a “pale malt”– different kilning schedules and moistures could produce different malts).
But did it work? Was the barley’s dense endosperm carbohydrate matrix broken down into smaller starch granules, and did I manage to break down protective cellulose/protein wrappers? Did this process produce the alpha- and beta-amylase enzymes I’ll need during brewing?
The only way to know is to mash it– and after an hour soaking in 150F water it had produced a reasonable conversion of starch to sugar as shown by a non-zero Brix reading, and by taste test. It even made an acceptable one-pint-mason-jar-microbatch of saison (but a rather bland and thin one– it could use some specialty malts).
To be further continued in the malting experiments…