Home Malting Procedure (by Jon Stika)
Major Malting Varieties of Barley include; Robust, Morex, Klages, Excel, Harrington, Stander, and Conlon. You want to start with plump, low protein malting barley. Feed barley will work but will make very poor brewing malt.
Steeping
Soak barley (or other grain to be malted) in cool, hard water for 8 hours. Drain, then let stand 8 hours stirring a few times if possible. Soak again for 8 hours then drain and spread about ¾” deep over a layer of paper towels on roasting pan or cookie sheet, place inside a black plastic trash/leaf bag and fold under end of pan to hold in moisture.
Germination \ Modification
Let grain sprout in a cool 55F to 65F place until the acrospire (shoot, not roots) is between ¾ and 1 times the length of the grain, this should take 3-5 days. Stir grain twice daily so the roots don’t form a “mat” that could mold and moisten if necessary to keep roots tender and germination proceeding. Do not keep germinating grain so wet that mold develops. Test for modification* by biting the grain and/or peeling the husk back to see if the interior endosperm is white and crumbly inside all the way to the tip. At this stage, there will probably be 4 or 5 rootlets an inch or more in length. Wheat or corn will usually take less time to sprout than barley.
Drying and Kilning
Dry malt at a temperature of 100 F to 125F in a food dehydrator until the malt contains 12% moisture (weighs 18 ounces for every 16 ounces of barley started with). This will take 8 to 10 hours in a food dehydrator. Finish drying the malt at 140F to 160F to 6% moisture in a food dehydrator (back to original weight of 16 ounces for 16 ounces started with). Kiln the malt in the oven at 170F to 190F for 4 hours to produce pale malt, and 212F to 225F for 3 hours to produce “Vienna” malt. Malted wheat or corn should be dried entirely at 100 F to 125F and not kilned at all.
My General Electric oven set on the lowest “warm” setting ranges from 155F to 205F which makes pretty nice pale malt that yields very close to the extract I get from commercial pale malt.
Clean the dried rootlets from the finished malt by working it over a sieve or screen. The rootlets will give a somewhat bitter flavor to your malt if they are not separated out and get included later on in the mash.
*”Modification” is the process of the barley germinating and releasing enzymes that begin to break the endosperm down into starch molecules. Drying stops this process when the endosperm has been converted to starch and the enzymes necessary for starch conversion to sugar (maltose) are also produced. Drying the malt at too high a temperature will destroy the enzymes and the starch won’t convert to sugar during mashing later on. Be sure barley has modified to starch and don’t dry at a temperature over 125F until malt is dried down to 6% moisture or less. At this point the enzymes are “safe” because there is no water for them to be “cooked” by and destroyed.