Malt is one of the four ingredients in beer and can certainly be the most expensive. The oldest maltsters are located at Warminster Maltings in Wiltshire, England. They have been malting since 1855, but lack of experience doesn’t mean you can’t start your own malthouse at home.
Malting at your home takes just a few simple tools and ingredients. This process will take the starches in barley and turn them into something that can be eaten by yeast in order to make beer.
Step 1: Soaking the Barley
Tools and ingredients needed:
- a food-safe bucket
- whole raw barley (one to four pounds to start off with)
- cool water
- a colander
Fill the bucket no more than halfway full of barley and let it soak for eight hours. This starts to hydrate the barley and wakes up the enzymes which start the conversion. Also, it removes dirt and other things you don’t want in your malt, which leads to a better-finished product.
Be sure to keep the bucket of malt cool (between 50°F and 60°F). It can sit for up to sixteen hours, but any longer and the barley will run out of oxygen and die before the process gets going.
After this initial soaking, drain the water out and wash the grains to get rid of any dirt clinging to the grain and rinse the soaking bucket with hot water to help prevent bacteria or mold from taking hold during the malting process.
Let the grains rest in the soaking bucket without water for eight hours. This will give it time to take up oxygen; you can stir occasionally if you want to.
The goal of the soaking is to get chit to grow out of the grains. Chit are small white roots that grow from the bottom of the grain. The goal is to have almost all the grain showing these roots, before proceeding to the next step.
The soak and rinse cycles can be repeated as many times as needed until the chit growth is achieved. If you do more than four cycles and aren’t seeing signs of chit however, then the grain isn’t viable and you’ll need to throw it away and try again with a different batch.
This can also be used as-is to brew as chit malt. It has uses as a specialty malt that has more protein compared to other base malts which help improve haze and potentially in the creation of stable haze. Since it hasn’t been kilned at all, it won’t contribute any color to the final product. Be warned that this is really high in beta glucan so an additional rest will be needed in mashing.
Step 2: Germination
- a large plastic container
- water spray bottle
Now that the enzymes are in full swing of chewing up starches it’s time to let them grow. Spread the grain out so the thickness of the grain bed is one to four inches. This will allow you to easily control the temperature and moisture of the grain.
This step will take several days and involve trying to keep the malt at 64°F while letting it breathe.
The whole process is exothermic, which means it gives off heat. Turning the grain two to four times a day spreads this heat out evenly, which stops the growth from bunching up and making clumps as well as keeping the moisture content consistent. Spritz the top of the grain bed with water as needed to stop it from drying out which could hinder the process.
If the germination step goes well, the malt will smell like fresh-cut grass or even cucumbers. The roots will be white and crunchy. Throughout the process, the roots of the malt will turn a darker color. A moldy or rotten smell is a sign the temperature is too high or perhaps that there is too much moisture. If you see any mold growing then dump the batch. Mold can contain toxins that are lethal to humans in small doses.
Keep the germination process going until acrospires (shoots from the bottom of the grain) are equal in size as the grain kernel. This is when the grains are ready for the last step, called kilning.
Step 3: Kilning
- an oven capable of temperatures as low as 120°F
- a food dehydrator
- a colander
This last step removes the water from the grain which stops the enzymes from continuing to break down starches. This saves them for mashing.
Heat the grain up to 120°F for eight hours to remove the bulk of the water. A food dehydrator will be better for this step as it moves air over the grain. Leaving the oven door cracked open will have a very similar effect.
Increase the temperature to 145°F for eight hours to finish driving away from the water that’s bound deeper within the grain.
Curing is the last kilning step. This drives off chemicals that can lead to funky off-flavors in the beer, and curing also helps the beer develop a darker color and character.
Set the oven to 180°F and leave the malt in the oven for three hours. You can let the malt sit longer which will cause the malt to develop a deeper color and flavor. This is when you can begin experimenting to make the perfect custom malt.
The attached rootlets can lead to bitter flavors in the fall beer. Luckily, they fall off very easily at this stage. After curing move everything over to a colander and shake the malt to break off the rootlets. Do this outside because it will make a mess in your kitchen.
Store the malt in a cool and airtight container and you’ll have your own malt to start brewing with. Once you have the basic processes down, you can experiment with final curing times and temperatures to create unique flavors and colors in a beer. Cheers!