Traditionally, malted grain sorghum (variety caffrorum) comprises at least half of the grain bill in home and village-brewed versions, the other half being millet or maize. Keep in mind that this sorghum is not the same as the "sweet sorghum" (variety saccharatum) used to produce the molasses-like syrup commonly found in North America. Please consult my articles in the 1995 Special issue of "Zymurgy" for more details on sorghum, its varieties, and the various methods used to malt it.
The essential steps required to produce opaque beer are sour mashing, boiling, sugar mashing, alcoholic fermentation, and straining. For the purpose of this exercise, we'll keep the sour mashing and sugar mashing steps simple. Souring in particular is very difficult to control at home (ask any lambic brewer), and opaque beer, when freshly consumed, should have just a hint of sourness anyway.
Here's my very basic recipe for traditional opaque beer (makes about 8 liters or 2 gallons):
1/2 kilo (1.1 lbs) sorghum malt
1/2 kilo (1.1 lbs) unmalted millet
Packet Red Star baking yeast
Crush the millet and boil in water for about 15 minutes to gelatinize starches. Drain and add to crushed sorghum malt in the mashing vessel of your choice (I use my 3 gal brewpot). Add 4 liters water at 160 degrees F (Sorry, don't have my centigrade converter handy) to reach mashing temp of approximately 150-155 degrees F. Mash for 1 hour.
Transfer liquid portion of mash to fermentation vessel by pouring entire contents of mash vessel through fine-mesh wire basket. Sparge grains with sufficient hot (~170 degree F) water to obtain 8 liters of wort. Let wort cool naturally overnight or until reaching room temperature.
Once at room temperature, check the original gravity of wort. Full starch conversion should result in an OG of 1.030-1.032. Depending on the age and condition of the sorghum malt (which has fairly low disatatic power anyway), you may need to add a small amount of corn sugar to bring the gravity up to this level.
Add the yeast (preferably rehydrated in a little warm water) and one cup of additional crushed sorghum malt (to help induce lactic fermentation). Stir vigorously to combine ingredients and oxygenate the wort.
Ferment for 2 days at room temperature (65-75 degrees F is optimum), then strain beer through wire basket once again into storage vessels (I use two 1-gallon glass jugs). Refrigerate and serve the same day.
The beer, when fresh, is opaque, slightly pink-colored, yeasty, and very refreshing. If kept for several days, the lactic sourness grows but never makes the beer undrinkable. Of course, I love traditional Belgian lambics as well, so YMMV.
This is the same beer Jim Busch mentioned in his posting awhile back, and Wendy and I both felt it was far tastier than anything we sampled in Africa (from both industrial and village breweries).
I'm currently looking for a source for grain sorghum in the U.S. as I'd like to try some malting experiments. The sorghum malt we used was hand-carried back from Africa.
Have fun with this, and feel free to experiment with ingredients and techniques. Maize or wheat grits can be substituted for the millet, and several brewers (including Charlie Papazian, who has published his recipe in "au Juice" magazine) have suggested that malted barley can be successfully substituted for malted sorghum. I've never tried this but might give it a shot down the road.
It'll be interesting to see how the other batches in the "sorghum challenge" turn out.