This is a short how-to on how I process spent beer grains from home-brewing beer into a healthful, tasty, and inexpensive ingredient I can use in bread, cornbread, stews, and even cakes and cookies. I buy and use grains for making beer, so this product is essentially free, as well as full of delicious sugars, calories, and digestible fiber. You will need a food processor and a food dehydrator to do this properly, although your oven might substitute for the dehydrator in a pinch.
Step 1: Getting Your Grains
The spent grains will initially look like this, wet from the beer-brewing process. I have had good success freezing them immediately after brewing for future reference, but this adds another step to the process since you must first warm the grains to room temperature before processing them further. For a few pounds of grain frozen into a block the warming step involves leaving them on a cookie sheet at room temperature for a day or so.
Step 2: Dry the Grains First
I spread the grains into the drier in a relatively thick layer -- say a quarter inch or so. On my drier, it typically takes only 8-10 hours to dry the grains to a nice crispy turn. If you leave it running overnight or while you're at work you should be fine. Most dehydrators use a screen to hold the drying items. You'll have to spread the grains on newspaper or waxed paper to keep them from falling through when they're finished.
Step 3: Get the Grain Out of the Drier
The dried grains will shrink and lighten in color. You can remove them and put them into a bowl.
Step 4: Remove Grains From Drier
This is what you'll have after the drier has run. The grains stick together lightly, but you should be able to crumble them in your fingers.
Step 5: Load the Dried Grains Into Your Food Processor
I usually fill my food processor about 3/4 full of dried spent grain. Of course, you want to use the big steel 'blender blade' for this.
Step 6: Run the Food Processor
After you run the food processor for a minute or so, you will have the final product. You can store it with your flour; it has almost no moisture, so it should last in a sealed container for a good long time. I typically store my flour in the freezer, where it will last indefinitely.
My standard corn-bread recipe includes a half-cup of spent grains substituted for a half-cup of the cup of flour in the recipe; this gives the cornbread a darker color and sweetens it just slightly. A quarter-cup of spent grains will make your bread slightly darker and moister; you can use up to a half-cup of spent grains if you supplement your all-purpose flour with gluten and increase your cooking times slightly. Cornmeal will oppose the effect of spent grains in bread, so if you add cornmeal as well as spent grains you can keep the time in the oven roughly the same. You can also use these grains to fortify stews or ragouts, where they'll add a slight nutty taste to the food.