Brewing with millets: ragi, jowar and bajra in beer

Meet the three millets

The three millets most homebrewers can buy easily in India are:

• Ragi (finger millet): small, reddish brown grains with an earthy, slightly nutty flavour. In the hills of Sikkim, Darjeeling and Nepal, fermented finger millet is the base of the traditional drink tongba, sipped hot through a bamboo straw.
• Jowar (sorghum): larger, pale grains with a mild, slightly sweet taste. Sorghum is the traditional brewing grain across much of Africa and is used there in both traditional and commercial beers.
• Bajra (pearl millet): grey green grains with a stronger, grassy flavour. It is rich in oil, so its flour goes rancid quickly once milled.

All three can bring colour, flavour and a story to a beer. None of them behaves quite like barley.

Why millets need cooking first

Starch in grain sits in tight granules. Before enzymes can break it into sugar, the granules have to swell and burst in hot water, a process called gelatinisation. Barley malt starch gelatinises within a normal mash range. Sorghum and the millets need higher temperatures, often well into the 70s °C and higher, which is above where the main mash enzymes survive for long.

So raw millet in an ordinary mash mostly passes through unconverted. You get cloudy wort, poor extract and a starchy beer. This is the same problem brewers solve with rice and maize, which our guide to rice and maize adjuncts covers in detail.

The answer is a cereal cook: a separate pot where you boil the millet before adding it to the main mash.

How to do a cereal cook at home

1. Mill or crack the millet coarsely. Millet flour from the shop works, but buy it fresh, especially bajra.
2. Mix it with about 10% of your barley malt and four to five times its weight in water.
3. Hold at about 70 °C for 15 minutes. The malt enzymes thin the mixture so it does not set like porridge.
4. Bring to a boil and boil gently for 20 to 30 minutes, stirring often. It sticks and scorches easily.
5. Add the hot cereal mash to your main mash. It will raise the main mash temperature, so start the main mash a little cooler and use it to hit your target.

Flaked or puffed millet, sometimes sold as a breakfast food, is already gelatinised. You can add it straight to the main mash, which is much easier.

Enzymes: barley does the work

Barley malt carries plenty of enzymes, called diastatic power, to convert extra starch. A grist of up to about 30% raw millet with the rest a good pale malt converts well. Above that, conversion becomes less reliable. Our guide to enzymes in the mash explains how the two main enzymes divide the work.

Malted millets exist and you can malt them at home: steep the grain, let it sprout for a few days and dry it gently. Malted sorghum and millet generally have less of the enzyme beta-amylase than barley, so on their own they produce less fermentable wort. That is one reason all-millet beers are difficult.

Lautering and flavour

Millets have small grains with little husk, so a grist heavy in millet can turn into a sticky mash that runs off slowly. Adding rice hulls at 3 to 5% of the grist gives the bed structure. Sparge slowly and do not stir the bed once it has settled.

Flavour depends on the millet and how much you use. At 10 to 20%, jowar lightens body and adds a faint sweetness, a little like rice. Ragi gives an earthy, slightly bready note and a touch of reddish colour. Bajra is the strongest and can taste grassy or stale if the flour is old. Smell it before you brew: rancid bajra smells like old cooking oil. That note goes straight into the beer.

A first millet beer

For 20 litres, try a pale ale with about 80% pale malt and 20% ragi, cereal cooked as above, plus a handful of rice hulls. Hop it gently and ferment with a clean ale yeast at 18 to 20 °C so the grain flavour shows.

A note on gluten: millets and sorghum contain no gluten, but a beer that also uses barley does. Making a fully gluten-free millet beer means using only gluten-free grains and dealing with their low enzyme levels, which is an advanced project.

Cooking adjuncts, managing enzymes and getting a sticky mash to run off are core brewing skills. Learn them on millets and you can brew with almost any grain an Indian market sells.