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Hello, and welcome to the church of home-brew. Today, We will delve into Peter, chapter 14, Behold: the Miracle of spent grain flour!

There is a vexing question that plagues every person who brews beer at home: What do I do with this pile of gooey grain stuff that’s sitting in my mash tun? It even vexes people who brew extract beer since they inevitably end up with a small pile of grain. It just seems like a waste to throw it in the trash. You can throw it in the compost bin, but you have to wait until it cools down enough so it won’t burn the microorganisms that are turning your yard waste and food scraps into valuable soil. If you are fanatical about cleaning your gear as quickly as possible, that can be a pain in the butt.

Well, I am here to spread the good news! There’s something easy and awesome that you can do that may even make the spouse/partner happy (well, happy-ish, maybe incrementally happier? Less annoyed?). You can use your spend brewing grains to make “flour”! And then, you can use that spent grain to help make BREAD! And, it makes the bread taste better! And makes your bread better for you! And it works in pizza dough too! That’s right, with a minimal amount of effort you can take your bread baking to a whole new level! Or, you can start baking bread at a level higher than all the other beginning bread bakers! Or, you can make healthier pizza!

Replacing just 10% by weight of your regular bread flour with spent grain flour will increase the fiber and protein content of your bread by 50% because you have taken most of the starch out of the barley, rye, wheat, whatever, and fed it to yeast in order to perform the miracle of creating beer (Not kidding here. Monks who brewed beer didn’t have White Labs down the street or a home-brew store that sold little sanitized packets of yeast. Heck, at that point, they didn’t even have Louis Pasteur to tell them that there was such a thing as yeast. The fact that they could leave their vats of wort sitting out in the attic and it would transform into beer over the course of a few weeks was considered a miracle from God. When young monks asked how that happens, the answer was literally “God is good, my son.”) So, by my calculation, making bread healthier will mean you will have just performed your second miracle! They make saints out of people who just perform one. And your miracles are repeatable!

Once you’ve brewed your beer, all you need to perform your second miracle is an oven and a rimmed cookie sheet or two, a big spoon, and a food processor.

Note: If you don’t brew your own beer, make friends with someone who does and offer to take their spent grain off their hands. They will be happy to hand it off especially if you promise them some bread, pizza dough, dog treats, … etc. If you go this route: find out what is in their grain bill and provide them with a 1 gallon container (ziplock freezer bags work well) for every 2 lbs of grain. Then get over there as close as you can to the end of their brew day so they aren’t devoting huge amounts of refrigerator space to keeping the grain for you. You may even end up getting some beer from them! There’s something particularly satisfying when you can drink a beer and eat some cheese on a bread made from the grain used to make the bread.


  • Rimmed baking sheet – if you have two, awesome, if you have more, even better. You will need as many racks in your oven as you have rimmed cookie sheets though, so don’t be crazy.
  • Oven that can be set at 200ºF (90ºC) or lower. I go at 190º (87ºC)
  • Big spoon/ice scoop/something like that. I use an ice scoop because somehow we ended up with two. I’ve also used my brewing spoon.
  • Food processor (or grain mill attachment for a stand mixer if that’s how you roll the grain mill will give you more flour like flour, but the food processor will leave tiny chunks that will make the bread prettier)


  • Spent grain from brewing beer

Time: about 15 minutes active, 13 hours total.

Yield: About 1 quart per pound of grain you started with. That’s a total guess based on what I get out of my brewing. Your results may vary.


  1. Set your oven to somewhere between 150ºF (65ºC) and 200ºF (90ºC). I go at 190ºF (88ºC). The lower you set it, the longer it will take to dry out. The higher you go, the more frequently you should check on it.
  2. Scoop out grain from your mash tun and spread it on the baking sheet so that it evenly covers about 1/4″ deep. If you go deeper than that, it will take forever to dry out and it will become really messy as grain will get everywhere when you are raking through it with a fork. You want it about halfway up the rim of the baking sheet because you are going to periodically gently stir the grains and you don’t want them spilling all over the place any more than necessary. Plus it helps the grains dry out faster. Note: You can also put your grain in containers and refrigerate it to do this later. I use 1 gallon ziplock freezer bags. A 1 gallon bag of grain will fill up 3 baking sheets nicely.
  3. If you have more than one baking sheet, repeat until all of your sheets are full NOTE: If you have extra grain, you can stick it in the fridge and use it for other purposes (more recipes to follow), or you can make more batches of flour by refilling your baking sheet another day.
  4. Put the sheet(s) in the oven.
  5. Every 4 hours or so, open the oven and given the grains a gentle stir with a large serving fork or something like that to bring the wetter grain from the bottom up to the top where they can dry out faster. I usually do this by pulling grain from the sides toward the middle and then digging down and gently pushing grains from the bottom of the middle out to the sides, but you may figure out a better way. If you do, you do what works for you. The 4 hours thing is not scientific. I usually start this process on my brew day if I’m not cooking something that requires the oven for dinner. I start heating my liquor (water) at around 10am, mash in around 11am, a half hour protein rest at 135ºF (37ºC), an hour sacch rest at 155ºF (68ºC), 20 minutes at 172º (78ºC), then it takes about 10 minutes to sparge and drain. Once I get the kettle on to boil, it’s usually around 2-2:30 pm and I can get the baking sheets in the oven. I’ll given them stir around the time I start making dinner, one before bed, then check in the morning and they usually need another hour. Then it’s time to go to the next step.
  6. After 12-16 hours, depending on how well drained/cold your mash was, and how warm your oven was, you will have a bunch of crunchy stuff that looks like it should be a breakfast cereal sold at the local hippy co-op.
  7. Take out the baking sheets and let them cool off a bit. This isn’t going to take long because they aren’t really that hot.
  8. Using your big spoon/ice scoop/whatever, put the dried grain into the food processor. I usually get one baking sheet per bowl of the food processor but your food processor and baking sheets might be different from mine. Make sure you have the blade in place first, I speak from experience.
  9. Turn it on and let it go for about 3-5 minutes or until you feel good about it. This is the least precise recipe you will find on this blog so far.
  10. Store like you would store flour. I use some fancy Italian jars I bought when I was young and stupid and trying to make my apartment look cool.
  11. You should get about 2 quarts of “flour” per 4 lbs dry grain going into the brew. My Belgian Dubbel has about 13 lbs of various grains and I use a little more than a third of that to make “flour”. A bit more than a third sits in containers in the fridge waiting to be used for other stuff, and the rest cooled down enough by the time I was ready to clean up that it was okay to go in the compost bin.

Final thought: the grain you use in your beer will affect the bread. The darker the beer, the more profound the effect on the bread both from the point of view of color and flavor. The spend grain from my saison produced something that looked a lot like a light rye bread and tasted like a slightly more flavorful french boule while the grain from the Dubbel made for a really hearty whole wheat type bread which actually was a little purple because of the chocolate rye I use in the beer.

Now go forth and spread the gospel of the spent grain!