Confessions of a Breakfast Cereal Brewer

If you asked me “Why brew with Grape-nuts?” I might answer:

“Why not?”

More important, when rearranged the letters in “Grape-nuts,” spell “sparge-tun.”

But I would probably think a bit longer and tell you the truth: I was perusing Michael Jackson books recently and read his description of the Russian brew kvass, made from bread. He mentioned kvass during a discussion of the theory that ancient brewers baked their grains into pre-beer bread, creating a primitive kind of starch conversion in the days when the secrets of malting and mashing were still just that, secrets.

I was suddenly struck with the memory of a little story I read some 15 or 20 years ago on the side of Post Grape-nuts breakfast cereal box.

For worthless information my mind is a steel trap. So it is no surprise that I can remember something like a publicity piece printed on a cereal box I read as a pre-teen.

The cereal box story was about future food mogul C.W. Post experimenting with new breakfast foods in his 19th century home kitchen. Post made dough from ground barley and wheat. He baked it and what came out of the oven were rock-hard, inedible bread brickbats. Undeterred, Post hammered them into chunks and ground them in his hand-crank coffee mill.

From the grinder came little nuggets of nuttiness, satisfyingly sweet and crunchy when topped with milk. Grape-nuts were born.

So, why brew with Grape-nuts? I figured if they are still made anything like the old recipe, maybe there is a way to force them to become beer.

A seed of obsession was planted.

Not satisfied to just think about doing it, I started a journey down new roads of homebrew knowledge to make it work. By the time the trip was over, I would have made the transformation from extract to all-grain brewing. I started by calling the toll-free information line of Kraft-General Foods, Post’s parent conglomerate, to see if Grape-nuts were still baked.

After I pressed the appropriate sequence of automated operator buttons, an unnaturally pleasant young man named Chris answered. I told him I had questions about Grape-nuts. I started by telling him about the story I read on the box.


“You read that on a Grape-nuts box?” Chris asked. Probably printed before Chris had started on solid foods. “Yeah. Well it was a long, long time ago. Just wondering if they were still baked.”

Chris was back on familiar ground: That material was in his scripted index cards.

“Yes, just like the original recipe. The baking creates grape sugar. That and their nutty taste and texture gave them the name Grape-nuts,” he said, brightly.

Chris volunteered the bit about the grape sugar. I did not even ask about starch conversion.

I asked “Do you know their proportion of wheat and barley?”

“That would be proprietary,” Chris said. I guess they have to protect themselves against cereal spies. I thanked Chris and said good-bye.

The next step in my weird odyssey was to learn what kind of sugar is called “grape.” My garden-variety dictionary provided the answer. “Grape sugar: dextrose, the sugar of grapes, a term popular in the 19th century.” Right about the time C.W. Post was pulverizing Grape-nuts by hand in his home coffee mill.

Since my conversation with Chris, I read Charlie Papazian’s account of making ancient Sumerian beer with bappir, hard barley bread.

I knew I had to try it. Even if I hadn’t a clue how to go about it.

First I infused six pounds of Grape-nuts in water and heated it until the pan scorched. I dumped it into a fermenter with a packet of dry yeast. (I didn’t even strain it.)

It went immediately lactic, pinning the household olfactory disgust-o-meter. I flushed the whole sour mess down the commode.

Obviously, I was missing something. I hit the books, rereading Papazian and Dave Miller’s chapters on starch conversion, enzyme action, and the mash — chapters I had only skimmed before. This time I took notes.

As I studied the literature, it became evident that the Grape-nuts were going to need some help if they were ever to become fermentable. At that point I really started to pay attention to the diastatic power of malted barley and the whole enzyme-action thing. That is, the special enzymes that give malted barley its ability to convert built-in starch supplies to sugar.

And I learned that six-row barley is best for converting adjunct grains, since it has diastatic power to spare. In other words it can convert its own starch supply, plus more starch from other sources in the mash. Six-row also has more husk, making a more effective filter bed at sparge time.

I learned that starchy adjuncts must be heated. The heat gelatinizes the starch, making it susceptible to the converting power of malted barley. I made the assumption that the industrial ovens at Post probably gelatinized Grape-nuts.

So I got some six-row and cooked up a mini-mini mash in a small saucepan on the stove top. I mashed half six-row and half Grape-nuts. It converted partially, very stubbornly. So I made the six-row to Grape-nuts ratio two to one in the final batch.

I knew Grape-nuts contained wheat. I did not really want to make a weiss or weizen, so I scanned recipes and style sheets for a barley-based brew that used wheat as an adjunct. I found several recipes for altbier and kölsch, Germany’s top-fermenting ale styles, that fit the bill. I went with the kölsch.

I used Irish moss and a bit of black malt to help clear the brew, crystal malt for color, Tettnanger hops for boiling and flavor, and Wyeast’s European ale yeast. Chances are, you won’t see this next to the muffin recipes on the Grape-nuts box any time soon.

Rice Krispies, Yes. Froot Loops, No.
All breakfast cereals are rich in starch, making them natural candidates for brewing. They should be used as adjuncts; that is, non-malt sources of starch. However, before using your favorite breakfast cereal in beer, consider a couple of key points.

First, when starch is heated in a moist environment, it gelatinizes. Gelatinization changes the starch’s form from a crystalline to a less organized state, allowing amylases (enzymes important in changing starch to sugar) easier access to the molecular structure of starch.

Some starches, such as barley and wheat starch, gelatinize at temperatures typically found in a brewer’s mash. Other starches, such as rice and corn starch, must be gelatinized before mashing because of their high gelatinization temperatures. Most commercial breweries gelatinize these starches by boiling them before mashing. Three common, effective alternatives to boiling are steam rolling, flaking, and torrification (commonly known as “puffing”).

Rolled cereals (oats), flaked cereals (Corn Flakes), and torrified cereals (Rice Krispies and Sugar Smacks), are common breakfast foods. They can each be added directly to the mash as an adjunct without special treatment. Of course malted barley is still needed to provide enzymes for mashing and the husks for lautering.

The second key point involves the other ingredients found in cereal besides a starch source. Some cereals contain simple sugars as sweeteners, fats and salt for flavor and mouthfeel, and vitamins for nutritional purposes. Some cereals have unusual ingredients, such as blue stars, pink diamonds, and green clovers that are made of something strange and provide no known nutritional benefit.

In general stay away from cereals that contain a lot of fat or unidentified tidbits. Fats, commonly found in granola cereals, are detrimental to beer foam and can lend rancid flavors if the cereal is old. Salt will increase beer sweetness and palate fullness in moderate concentrations (less than 150 ppm) and may lend salty flavors at higher concentrations. And blue, pink, or purple tidbits simply don’t belong in beer.

Based on their published ingredients lists, Puffed Kashi, Cheerios, Corn Flakes, Rice Krispies, Sugar Smacks, Special K and, of course, Grape-nuts would all make interesting adjuncts in any home brewery.

Issue: August 1996