Special Ingredient: Brewing with Bread

Don’t let that extra loaf go to waste—try throwing it into your mash tun. Here, Sam Fleet of Brussels Beer Project breaks down the unexpected benefits of brewing with bread.

Joe Stange Jun 29, 2021 - 9 min read

Special Ingredient: Brewing with Bread Primary Image

Photo: Brian Zanchi/shutterstock

Here is a disconcerting factoid: The U.S. Department of Agriculture estimates that more than 30 percent of the United States food supply ends up as waste—about 133 billion pounds of it. That goes to landfills instead of hungry families while the resources that produced it could have been used for something else.

Of course, food waste is an issue virtually everywhere. In Belgium, for example, they produce and consume a lot of bread (and their bakeries are as good or better than the ones found in France, for whatever that’s worth). It’s the most common breakfast food there and accompanies most other meals, too. By one estimate, the Belgians eat about 500,000 metric tons of bread per year.

However, they like it fresh. Inevitably, many tons of loaves from supermarkets and bakeries end up tossed out.

Calling attention to the issue of food waste was the original impetus behind Babylone, the “bread bitter” released by Brussels Beer Project in 2015. At that time, about 20 percent of all the food waste in Brussels was bread. The beer’s launch made something of a news splash, attracting international recognition for the small brewery and the cause. In Britain, the celebrity chef Jamie Oliver—who frequently speaks out against food waste—even featured Babylone on his TV show.


A strong, bitter, amber-colored ale—checking in at 7 percent ABV and a robust 55 IBUs—Babylone has been part of the brewery’s core range ever since.

Sam Fleet, the Brussels brewery’s British-born head brewer, says that they produce about 1,000 hectoliters—or about 850 barrels—of it per year. Each time they brew it, about 20 percent of its grist weight consists of unsold bread, primarily from the supermarket chain Delhaize. A local nonprofit in Brussels takes the unsold bread and dehydrates it over low heat, reducing its weight by about 50 percent. Then it goes to the brewery as crumbs and straight into the mash tun.

Here’s the thing: It’s not just a feel-good gimmick.

“Actually, this bread brings quite a lot of character,” Fleet says. “I’m really interested to see what other people do with bread. I mean, I hope this really inspires a few people to brew some kind of bread ales of some description because the bread we use brings a lot of character—it brings a lot of salt, it brings a lot of mouthfeel. And that’s really balanced with some of the quite robust [recipe] that we’ve got going on there. It works really well in the mix.

Fleet says they have tried brewing Babylone without the bread. “It’s still a nice beer, but it’s not the same,” he says. “I’m always impressed with how much the bread does bring.”


Obviously, Babylone wasn’t the first beer to have some bread in it. If we want to go way back, historians say the ancient Sumerians were brewing beer from twice-baked barley loaves. Kvass, meanwhile, is a traditional low-alcohol beer typically made from rye bread in Russia, the Baltics, and other Eastern European countries.

Since the launch of Babylone, a few other brewers have followed the idea and taken it further. London-based Toast Ale—slogan: “A Beer with More Taste, a World with No Waste”—brews a lager and a few different pale ales with bread. Welsh brewer Tiny Rebel also brews a pale ale called Bread Board with leftover loaves. For whatever reason, the idea has yet to really catch on in North America.

Fleet says that while Babylone isn’t the brewery’s top-seller, they’re proud of how the idea has inspired other breweries. “And I hope it will also continue to inspire homebrewers,” he says. “I mean, there’s a ton you can do with bread, right? Bread is as diverse as grain.”

In fact, given the ways that bread can use various grains, it may be more diverse. Imagine the possibilities, any of which can add savory depth to your brew: dark rye–loaf dunkel? Sourdough-multigrain saison? Milk–bread rice lager? Pumpernickel porter?

Or, how about this: Bake bread with your spent brewing grains, then brew beer with it, then bake bread with those spent grains, then brew more beer with it. Is this the circle of life? If you want to take this bread-beer gestalt a bit further, consider doing what Scratch Brewing in southern Illinois does: They use their sourdough-bread culture to ferment most of their beers. (For more on that, see “Brewing with Sourdough Culture at Scratch,”


The bread that Brussels Beer Project adds to Babylone is closer to crusty white baguette. “The bread we use is kind of in the cleaner spectrum, but you still have a lot of salt; you have a lot of oil. And you need to factor those into your recipe design.”

What do you need to know about adding bread or breadcrumbs into the mash? The first thing is that it can become a gloopy mess and lead to stuck mashes. “We’ve learned from experience that any more than 20 percent of the weight starts to get really tricky,” Fleet says. “But we compensate. I mean, bread is full of everything that will give you a step mash, right? It’s full of beta glucans. I mean, it’s sticky stuff—if you leave a slice of toast sitting in a bowl of milk, it’s going to get grim pretty quickly, and really sticky.”

So, they use lots of rice hulls to help keep lauter times reasonable. Another option, he says, is to add a beta-glucanase rest to your mash steps—i.e., about 20 minutes at about 110°F (43°C)—just as you might if you were mashing with unmalted grains. Another of Fleet’s suggestions—especially if you want to go beyond the 20 percent threshold and add more bread—is to consider the use of exogenous enzymes to reduce viscosity and make lautering easier. “I think there’s no problem doing that,” Fleet says. “If you want to really bump up your bread additions, don’t be scared to use those enzymes.”

What does the bread do for the beer? In Fleet’s view, the salt adds a bit of umami, while the bread adds body—a thickness to the mouthfeel. “When we tried Babylone without the bread, it felt empty. It felt like we kind of stripped some element of it away even though it smelled the same. So, I think a lot of it is about the body.”

What also makes a difference is how you treat the bread before mashing with it. It need not be dehydrated, like the crumbs used by Brussels Beer Project. Want to throw in a heavy, moist loaf? Go for it. Want to toast it first and see how that affects the flavor? Do it.

Another thing to consider is how much extract to calculate—i.e., how much sugar will the bread provide to the starting gravity? Fleet says that at Brussels Beer Project they figure it at about 60 percent extract by weight—that compares to about 80 percent for pilsner malt, for example. “So, the method that we’ve got—dehydrating or slightly toasting and breadcrumbing—is actually quite efficient. But that doesn’t mean you won’t get flavor from just chucking some loaves in.”

Beyond those considerations, there is great potential for different types of bread to add significant flavor.

“What’s quite interesting is, I think, that’s all going to change depending on the bread,” Fleet says. “I can already see homebrewers using, I don’t know, fruitcake—or bread with seeds, nuts, raisins, you name it. All that stuff’s going to make it through into the final beer. … You know, I can really imagine some sourdough—some nice kind of sourdough bread. Sourdough rye could bring a really nice character to a brew.

“Just treat it as you would treat any grain when you design your grain bill,” he says. “I think bread is quite a legitimate ingredient there.”