I have been brewing home made beer since the 1980's on and off, but I began to brew all grain batches about four years ago when I moved back to Montana to help my aged parents take care of our family farm. This post is about making your own malt (sprouted and dried grains) which isn't very difficult provided you have a way to dehydrate it. I usually malt 16-pound batches of barley or 20-pounds of wheat at a time and use a large fruit and vegetable drier that my father built years ago to quickly dry it at a low temperature.
There are other ways to dry your malt, but whatever way you choose to do it, the temperature has to be low enough to not harm the enzymes in the grains so that they can be used to convert the starches into fermentable sugars when you mash your malted grain. Smaller batches can be spread out in trays in an oven at temperatures less than 125 degrees f. or so. I have also heard of people using an old cloths drier to dry their wet malt. It would work fine provided the heat is turned off and the grain is placed in mesh bag. I have actually used an old cloths drier (with heat turned off) to tumble my dried malt (in a mesh bag) and knock the sprouted "tails" off the malt--it works really well and is very fast. It takes only 10-minutes or so. OK this last thing before I explain how to malt barley and wheat; the reason you want to knock the sprouts off your dried grain is because they lend a grassy chlorophyll flavor to your beers, and the reason you want to dry your grain is so that you can roast some of it for flavoring malts. So, you must have a way to dry your malt before you decide to make your own malt.
What you will need:
A way to dry it as fast and at a cool temperature (below 125 f.) as possible.
Grain, two-row or six-row barley that is suitable for malting (that usually means plump kernels and, ideally--low protein). I also malt spring wheat and hard red winter wheat--wheat is even easier to malt because it doesn't have a porous hull like barley has, thus it is cleaner to malt. I use a lot of two-row barley since that is the main type of malting barley grown around here. There is a difference between six-row and two-row barley, but it isn't a concern for this post about malting your own grain.
You will need a cool place to keep your wet grain while it is being malted. It is very important to use cold water and keep your wet grain in a cool place otherwise it (barley) has a tendency to develop bacteria in the porous hulls. If you don't worry about using lots of water you should rinse your grains well before you start in order to alleviate the possibility of bacterial infection. The reason you need a cool place to malt your grain is because sprouting grain makes its own heat as it goes through the sprouting process and that contributes to bacterial growth.
It is nice to weigh the grain so that you know how well it will fit into your method of drying; it will expand almost double in size as it soaks up water so you need to plan for that. I put four pounds of barley or five pounds of wheat (wheat has smaller kernels) into four plastic dish-pans.
You will want a large colander or a screen (like for washing beans) to drain your grain and some plastic to cover the dish-pans for the time it takes your grains to sprout a tail about the length of the grain (about 48-hours). You will also want some kind of hand held strainer to collect the flotsam that floats as you rinse your grain.
Here is the process: (It works the same with wheat or barley)
Weigh out your barley into plastic dish-pans and rinse it well with cold water (if you have lots of water), we don't have lots of water here so I just cover the grain with cold water and use a hand-held strainer to remove everything that floats.
I choose a specific time of day to begin because it is important to only let the grain sprout for not much more than about 48-hours. Going longer than that may allow for bacterial infection, and the malt will have less enzyme power to convert starches into sugars the more sprouted it is.
You will want to note the time when you cover the grain with a couple of inches of cold water. I stir the wet grain to float off the debris and use the strainer to remove the straw, weed seeds, and insect parts etc. I usually do this at 1:00 pm, then three hours later I will drain all the water off at 4:00 pm. This is where you will use the colander or bean washing screen. You do not want to keep the grain under water for more than three hours because you can actually drown the seeds; I have found that three hours is adequate for our purposes. Cover the dish-pans with some plastic until the same time tomorrow.
At 1:00 pm, 24-hours later you cover the grain again with a couple inches of cold water (some people rinse the grain with cold water at this point before they hydrate it for the three hours). Drain it three hours later at 4:00 pm. Cover it with plastic and wait another 24-hours.
At 1:00 pm, check the length of the sprouts they should be a bit longer than the length of the seed, but to really be sure you have sprouted the seeds the right amount of time, you can cut one of the seeds lengthwise and use a magnifying glass to see if a leaf is trying to come out of the end opposite of the root. You want the leaf to be extending across the seed without poking out of the seed. Here is where it is good to start at ie. 1:00 pm--now you can let the sprouts grow a little longer if they need to--you will not, however, want to let them grow overnight--that would be too long and they would start to have a strong chemical smell.
There are a couple of ways to treat the wet grain after you have determined that it has sprouted long enough. The best thing to do with your wet grain, if this is your first time malting grain, is to dry it as fast and at a cool temperature as possible. Their is one other process you can do with the wet grain, though, that is to make "Munich malt" out of it before you dry it. I will tell you how to do that in a later post.