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What Happens to All the Leftover Grains After Beer Is Brewed?


One of the first steps in brewing beer involves soaking malted barley (and sometimes other complementary grains, too) in hot water to release malt sugars that’ll aid in the fermentation of your forthcoming brew (i.e. make it alcoholic). So what happens to that cereal when all’s said and done?

Most of it of it becomes compost, livestock feed, or otherwise gets disregarded, but Chef George Shannon, CEC, CHE, lecturing instructor of culinary arts at the CIA, explains that there’s a smarter use for this brewing byproduct:


What exactly is spent grain?

“Spent grain is the malted barley, and/or other grains, left over from the process of brewing beer. The brewer cracks the grain to gain access to its endosperm, and heats to extract it, which creates the wort — the liquid that becomes the beer after converting the starches to fermentable sugars.

When the wort is drained off, you have the leftover bran, protein and some minerals that are then used in several ways. Most of the time the leftovers are used foraAnimal feed, dog food, mushroom substrate or compost, just to name a few other uses.”


About how much spent grain is produced when brewing an average batch of beer?

“Different breweries have different kettle sizes and will vary on the amounts used depending on the type of beer being produced. Our brewery [at the CIA], Hutch, tells me you get one to 1¼ pounds of wet spent grain per pound of dried malted barley that you start with. You end up with about one or two pounds of wet spent grain per gallon of beer produced. In 2015, the US alone produced around six billion gallons of beer.”  


How can spent grain be utilized in the kitchen?

“It can be used wet or dried. When used wet it has a very short shelf life, seven days, and gives a unique textural component because of the size of the husk (bran) left after the grain is milled for making the wort. Dried, it can be ground using a grain mill to produce a flour that can be used in small amounts as an additive to a baked goods recipe. We have found not to exceed 20 percent of the total flour in baked goods or you lose the gluten needed for the recipe to work. The taste has a slight sweetness form the malting process, and I have had people describe a bit of Umami in the flavor from the drying of the leftover grain. The drying process also leads to a slightly darker color.

The one thing that differs from regular flour as far as usage or texture, is that the bran absorbs more water than regular or whole wheat flour and the final texture depends on how fine you mill the dried spent grain. The benefit of spent grain is that cup for cup, the spent grain has more fiber and protein than regular or whole wheat flour, and the recipe can be slightly lower in calories due to the extra water required in some of the recipes to hydrate the ‘flour.'”


How much spent grain is produced at The Brewery at the CIA?

“We produce about 500 pounds per a 220 gallon batch of beer, and we have produced 35 batches of beer in the past year — so about 1,000 pounds a month. I take about 30 to 40 pounds at a time.”


How does the CIA make use of its spent grain?

“Unfortunately, most of it is sent to a local farm, but we do use some of it in the High Volume Production kitchen, both wet and dry, in some of our baked goods recipes. A few other classes have experimented using it in things like falafel, vegetarian meatballs and a few other items.

One unique side note: The cows at most farms learn the delivery schedule, and I have been told [they] get rather excited on delivery day — the grain is pulled before alcohol production, but can ferment a little if it sits for a day or so in the barrels it is being collected in.”


Is there anything you think readers absolutely need to know about the stuff?

“There are a few restaurants and brew pubs that make use of it, but not too many. The most amusing fact I have learned about spent grain was right before two of my colleagues and I gave a presentation on the topic a few months ago. I had one of my students from India point out that in some places in India, the spent grain is referred to as “Poor Man’s Protein,” made into porridge and a flour that is called Sattu (which also contains chickpea flour, depending on the region), and is used as a secondary ingredient in other dishes like Litti Chokha.”

RELATED: Do you love all things craft beer? Check out our Craft Beer Guide!