Is light beer made by watering it down?

SDStaff Gaudere replies:

Oh, come on, I thought everybody knew how light beer was made. All you need is a bucket of regular beer, a thirsty horse, and an empty bucket.

Kidding aside, you’re both right. “Watering down” and reducing carbohydrates in the mash are used to cut calories, alone or in combination. Some companies do indeed simply dilute their beer, which reduces the calories but also the taste and alcohol content. Others add the enzyme alpha amylase, which converts most of the dextrins (which are carbohydrates responsible for much of the beer”s aroma and flavor) to alcohol, allowing you to use a lower-carb mash and make a beer with less carbohydrates but the same amount of alcohol. Or you can add glucose in the place of some of the barley malt (glucose is more easily fully converted to alcohol than the malt), which also bumps up the alcohol content while letting you use less carbs.

Most light beers, however, are made from a process made possible in 1964 with the commercial introduction of amyloglucosidase. This enzyme makes all the dextrins fermentable, unlike alpha amylase, which only affects some. All the starch in a beer can then be converted to alcohol, producing a slightly more alcoholic beer (about 1% higher than standard beer). In addition, because there are no dextrins left, the alcohol is absorbed more rapidly into the bloodstream. Tasteless beer that gets you drunk pronto? Sounds like a frat boy’s dream. However, not wanting their customers to get blindsided by an unexpectedly potent drink, and perhaps realizing they can produce the beer less expensively with the same intoxicating effect of regular beer, brewers generally add water to adjust the alcohol content to slightly below that of a regular beer. There you have it — a weak-flavored, low calorie (from the loss of dextrins and subsequent dilution) beer with the same “kick” as regular beer.

Those of us who actually like beer and are willing to imbibe a few extra calories to avoid beer that tastes like watered-down dregs might want to know who we have to curse for this insipid imitation of the real thing. The first true light beer was Gablinger’s Diet Beer, produced by the Rheingold brewery in 1967. Dr. Joseph L. Owades came up with the light beer making process used. “When I got into the beer business, I used to ask people why they did not drink beer. The answer I got was twofold: One, ‘I don’t like the way beer tastes.’ Two, ‘I’m afraid it will make me fat.’ It was a common belief then that drinking beer made you fat. People weren’t jogging and everybody believed beer drinkers got a big, fat beer belly. Period. I couldn’t do anything about the taste of beer, but I could do something about the calories,” he says in retrospect.

Owades also gave the formula to a friend at Chicago’s Meister Brau brewery, which produced Meister Brau Lite later that same year. Both Gablinger’s and MB Lite flopped, however. Miller bought Meister Brau, tweaked the light beer formula, and produced the first commercially successful light beer in 1975, Miller Lite. Currently light beers account for about 38% of the total beer market share, with a 25% greater portion of female drinkers than regular beer. Even micro-brewers are getting into light beer production, afraid to miss such a lucrative market.

Hmm. Perhaps I should give light beers another try. Where’s that horse?

SDStaff Gaudere, Straight Dope Science Advisory Board

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