Malt whiskey, and especially single malt, might sound a little sophisticated to some but actually, it is just as easy to make if you know what you’re doing. I’m sure many copper pot still owners out there know what I’m talking about but, if you’re new and are thinking about giving it a try, I’ll try to offer some more information on the malting process and the characteristics of malt whiskey below.
In America, regulated malt whiskey needs to be made from a fermented mash of no less than 51% malted barley and aged in new charred oak barrels at less than 125 proof. Malt whiskey can also me made from the same amount of rye but then will be called rye malt whiskey. If it’s been aged for at least two years, with no added coloring or flavoring and has not been blended with any other spirits or type of whiskey, it can also be called straight.
The malting process is basically creating the necessary conditions for grains to sprout, and then germination needs to be stopped by applying heat. Germination is produced through repeatedly soaking the grains in water which is followed by drying them with hot air, or in a hot environment. The malting process is used in order to develop the necessary enzymes to transform the starch into sugars. Malting also helps develop other enzymes, such as proteases, which give the grain a form that can be used by yeast.
Commercial breweries or distilleries perform the process in designated spaces which they call malthouse or malting floors. The specific flavor of different distilleries is obtained through the type and quality of the grains, but also the water they use for soaking and even the type of wood or fuel they use in the drying process. When the grain reached a moisture level of about 45%, it gets transferred to the malting floor, were it is constantly turned for about 5 days while it’s air-dried. The sprouted barley gets dried in a kiln to specific colors, from pale to crystal, amber, chocolate or black malts. Large industrial fans are now also used to blow hot air through the germinating air beds.
But to malt your own grains at home, all you need is some improvised equipment, which can hold your grains for sprouting and germination, and an oven or a kiln for drying and roasting. You can also try malting other grains, such as rye or wheat, then go on to brewing your own beer or making your homemade whiskey, by following the entire whiskey making process from choosing your mash bill, fermenting and distilling in your copper pot still.
Place about 3-4 pounds of raw barley grain (feed barley works well) in a bucket or a pot and fill it up with water until covered completely. Let it sit for about 6h – some prefer 4h, some 8h so just see what works for you, then drain it. Let it rest for another 6-8h, then fill it back and repeat over 48h.
After this you’ll want to keep your grains moist, at a warm temperature but stir often, about 3 times a day, to avoid mold from forming. You can have them laid on a tray (or a large terracotta pot as some think it absorbs excess water) and covered for about 3-5 days in order for the grains to air-dry at room temperature. You can also use a malt roller with a self-turning timer for this, which you can easily build yourself following some online videos; this can make the process faster and have your grains ready in about 2-3 days.
You’ll know it’s ready for the next step once the main shoot, the growing acrospires or plant embryo, has grown to approximately 75-100% the length of the grain – so make sure you cut open a few grains to double check that this is the case with the majority of them. At this stage, the grain is called green malt.
Next thing to do is dry the grains to stop germination and lock in the enzymes that convert the starch into sugars. This is usually done in a kiln or an oven, although I’ve also heard of people just leaving the grains in the sun during summer. Set the oven at about 100-125F for 24h. Try a grain and if it’s crunchy, it’s dry. Next, turn up the heat to about 210-215F and roast the grains for 2-3h to get your final product. You can then also run them through a sieve to get rid of the roots.
Posted by Jason Stone on