STATISTICS seldom do justice to Africa. Take beer consumption. The average African sips a mere 8 litres of commercially produced beer a year. Compared with the 70 litres or so quaffed by the average American, it sounds like Africans are bunch of party-poopers. But this is not so.

Africans chug admirable quantities of homebrew, made from sorghum, millet or more or less anything fermentable (see picture). A survey by SABMiller, a London-listed brewer, found that Africa's homebrew market is four times bigger than the formal market, measured by volume.

Brewers are betting that Africa's fast-growing middle class will want to trade up. Homebrew can be excellent, but it is highly variable, sometimes lumpy and lacks a certain cachet. SABMiller, which operates in 37 African countries, is trying to woo homebrew-lovers with sorghum and cassava beers that are consistently good. They are slightly sweeter and fuller-bodied than a mainstream lager, and cost a third less (though still far more than untaxed homebrew). SABMiller's Eagle, the world's first clear sorghum lager, launched in 2002 and brewed in Uganda, is already one of east Africa's best-selling beers. Demand for SAB's Impala, the world's first commercially produced cassava beer, brewed in Mozambique, is already outstripping supply after its launch four months ago.

SAB (formerly South African Breweries) was founded in 1895 to quench the thirst of gold prospectors around Johannesburg. Though now a global firm, it is pouring investment into Africa. Before its acquisition of Foster's of Australia in December, Africa (excepting South Africa) accounted for only 12% of SABMiller's sales, including soft drinks and bottling. Yet Africa attracts nearly a third of the group's total investments—$1.75 billion in the past four years, most of it on beer. The group's lager revenue on the continent, excluding South Africa, is growing by double digits.

With its French joint-venture partner, Castel, SABMiller has 60% of Africa's commercial beer market in volume terms, including a near-monopoly in South Africa. But other global brewers are keen to expand in Africa too, as they seek growth markets to compensate for flat or falling beer sales in the rich world. Heineken, already the biggest brewer in Nigeria, recently paid a princely $163m for two Ethiopian breweries put up for sale by the government. With Diageo, the leader in Kenya, these four brewers account for around 80% of the African market.

So far profit margins do not match those on offer in the rich world. But things should improve as incomes rise. Sales, which doubled by volume in the past ten years to over 100,000 hectolitres, could swell by 50% in the next ten years, reckons Morgan Stanley, a bank. The main bottleneck appears to be capacity. Most of SABMiller's 17 African breweries are operating at or near full throttle.

SABMiller's experience in Africa helps. It woos tipplers not only with traditional African beers but also non-alcoholic malt drinks, another fast-growing business. This plugs the brand and nudges people to trade up, from homebrew to mass-produced beer and finally to premium brands.

Some fret that brewers' sexy ads promote alcohol abuse. Graham Mackay, SABMiller's boss, brushes such criticism aside. His firm is a “force for good”, he says: it creates legions of jobs, provides a steady income for farmers and is the biggest taxpayer in some countries. It also sells cold drinks in a hot continent whose billion citizens are just starting to have a bit of spare cash. That's not a bad strategy.