Beano Brew!

I like quirky facts and the paths that link such facts, and I’m a big fan of the television show “Connections.” It always amazes me how the host is able to link so many disjointed facts into a continuous story. I sometimes play weird mind games with myself to determine if I have the knack for making interesting links between seemingly unrelated factoids. In this article, I present the connection between the garden-variety fart and a bottle of light beer — in this case, homebrewed light beer.

The Origin of a Fart

Farts, more appropriately called flatulence, result from consuming flatulents. One of the more amusing lectures in my undergraduate Food Chemistry class at Virginia Tech was on the topic of flatulent-containing foods. The best-known sources of flatulents are foods like beans, broccoli, cabbage, brussels sprouts and cereal grains that are rich in undigestable carbohydrates. These undigestable carbohydrates make their way into the intestine, where bacteria break them down into fermentable sugars. These sugars then ferment and produce carbon dioxide, just like a carboy full of fermenting beer. The result of this intestinal fermentation is the dreaded fart.

For those people who experience physical discomfort and social embarrassment resulting from flatulence, modern science has come up with several remedies. Some people lack the enzyme lactase and experience excessive gas from consuming dairy products. These folks can now purchase milk treated with lactase and can even buy lactase tablets, like Lactaid®, that allow the consumption of other dairy products without having to worry about any side effects.

Another enzyme pill, Beano®, contains the enzyme alpha-glucosidase, also known as amyloglucosidase (AMG), which is consumed before eating foods that contain undigestable carbohydrates, like beans. AMG is an enzyme that breaks the alpha 1 to 6 bonds found in certain undigestable carbohydrates, like raffinose (found in beans, for example). AMG also breaks alpha 1 to 4 bonds. When AMG is consumed along with certain foods it breaks the alpha 1-6 bond before these carbohydrates can make their way into the intestine. Pretty nifty stuff!

The History of American Light Beer

The domestic beer market was flat in the 1960s and 1970s. Domestic brewers wanted to expand their market by appealing to women, who at the time represented a very small portion of the beer-drinking demographic. Miller Brewing Company introduced Miller Lite in 1975 in hopes of appealing to women. Unlike other beers at the time, Miller Lite contained less than 100 calories per serving.

So how did Miller do it? They were able to reduce the caloric content of their Lite by reducing the amount of carbohydrates in the finished beer. Carbohydrates are present in beer because of branches found in the starch amylopectin — these branches are found at a chemical link between two glucose units in the amylopectin, called an alpha 1 to 6 bond. Most of the chemical links between glucose units in amylopectin are called alpha 1 to 4 bonds and all of the bonds in amylose, the other form of starch found in barley and malted barley, are alpha 1 to 4 bonds.

Malted barley contains the enzymes alpha- and beta-amylase and both of these enzymes break alpha 1 to 4 bonds of amylopectin, but not alpha 1 to 6 bonds. The key to Miller Lite is the enzyme amyloglucosidase, allowing almost all of the starch to be converted to fermentable sugars and for the resulting beer to have a much lower content of these calorie-containing compounds. Miller Lite opened the beer market wide open, and every domestic brewer had their own light beer in the following years.

Not every brewer uses AMG to produce light beer, which legally must contain 1/3 fewer calories than its regular counterpart. Calories in a 12-ounce beer serving can be reduced by adding water, starting off with a lower original gravity wort, adding highly fermentable adjunct syrups or boosting the content of fermentable sugars by using a long mash rest at temperatures around 140° F.

The Link Between Farts and Light Beer

A few years ago I was standing in line at the local grocery store and saw a bottle of Beano® hanging from the impulse-buy rack at the cash register. Recalling the lecture on farts from my Food Chemistry class, I became interested in how this stuff worked. As I read the ingredient label a light bulb flashed in my head! Beano® isn’t just for flatuence — it’s also the key to brewing light beer at home! Slip a couple Beano® tablets in the fermenter and the unfermentable carbohydrates will be converted to fermentable sugars and, voilà, light beer. The tablets could also be added during mashing, but it is easier and more effective to add them to the fermenter. The same sort of thing happens in sake production, during which Aspergillus oryzae (mold used to convert starch to sugar) secretes amylase enzymes, including AMG, as the yeast ferments the sugars produced by starch degradation. AMG in Beano® is derived from Aspergillus niger, a fungus used to produce a wide array of enzymes and acids, such as citric acid.

So for any homebrewer out there who is on a low-carbohydrate diet or has friends or family requesting a light beer, Beano® is the ingredient you have been searching for!

Beano® Braü

(five gallons, all-grain)
OG = 1.042 FG = 1.004 IBUs = 12


5 pounds pale malted barley
1.25 pounds flaked rice
2.6 AAU Mount Hood hops (2/3 ounce of 4% alpha acid)
2 AAU Mount Hood hops (1/2 ounce of 4% alpha acid)
3 Beano® tablets (150 enzyme units per tablet)
1 quart starter of American lager yeast (White Labs WLP840 or Wyeast 2035)
2/3 cup of invert sugar for priming

Step by step

Mash in malted barley and flaked rice with 2.25 gallons of 152° F water. Resulting mash temperature should be 140° F. Rest at 140° F for 30 minutes and increase temperature to 150° F. Rest at 150° F for 30 minutes and increase mash temperature to 158° F. Rest at 158° F for 45 minutes and then increase temperature to 168° F for mash-off. Transfer mash to lauter tun and allow mash to rest 15 minutes before beginning vorlauf. Recirculate wort until clear and transfer to brew kettle. Begin sparging with 168° F when grain bed has approximately one inch of wort above it. Collect a total of 6 gallons of wort.

Bring wort to a boil and add 2.6 AAU of Mount Hood hops. Boil for 55 minutes and add 2 AAU of Mount Hood hops. Boil 5 more minutes and stop boil. Chill wort to 52° F (if possible), aerate well, add yeast starter and Beano® tablets.

Ferment at 52° F until fermentation ends, about 10 to 14 days. Verify final gravity has been achieved with a hydrometer and rack beer to a secondary fermenter. Place secondary in a 38° F refrigerator and hold for one week and then cool refrigerator to 32° F (if possible). Let beer sit at 32° F for an additional 2 weeks before bottling. Transfer beer to bottling bucket, add 2/3 cup of priming sugar (dissolved in boiling water and cooled before adding), bottle and condition at room temperature for 2 weeks. Alternatively, transfer to a keg, carbonate and enjoy.

Extract Option:

Substitute 4.5 pounds of pale malt extract for the malted barley and 1.25 pounds rice syrup for the flaked rice. Proceed as above from boil.

Issue: March 2001