Black malt and roasted barley in stouts

Two roasted grains, two characters

Roasted barley is unmalted barley roasted to a very dark colour. Because it was never malted, it has a different flavour from a roasted malt: dry, coffee-like and a little sharp. It is the signature grain of Irish dry stout. Weyermann's roasted barley, for example, is listed at 1,000 to 1,300 EBC.

Black malt, sometimes called black patent malt, is malted barley roasted almost to charcoal colour, often around 1,300 to 1,500 EBC. The name comes from history. In 1817, Daniel Wheeler patented a drum roaster for malt in London, which allowed brewers to make very dark malt without burning it. That gave porter and stout brewers a powerful colouring malt.

How they taste

Roasted barley tastes of strong black coffee, dark toast and a firm, dry bitterness. It often gives a stout a reddish edge when held up to the light and a white or tan head.

Black malt tastes sharper and more acrid, with burnt toast and a slightly ashy note. A little goes a long way. In large amounts it can make a beer taste harsh. Brewers often pair a small amount with chocolate malt or roasted barley rather than leaning on it alone.

To learn the difference, steep a spoonful of each in a cup of hot water, strain and taste. You will find the roasted barley coffee-like and the black malt sharper.

How much to use

• Roasted barley: classic Irish dry stouts often use around 7 to 10% of the grist. Weyermann's sheet recommends up to 5% for normal recipes, with more possible in special ones such as stouts.
• Black malt: usually 1 to 5%. Above that it can turn harsh and ashy.
• Both together: some stouts use a little of each, for example 6% roasted barley with 2% black malt.

Neither grain has any enzymes. Both need a base malt that converts the whole mash.

A 20 litre Irish dry stout recipe

This recipe targets about 1.042 original gravity at a typical homebrew efficiency of around 70%.

• Pale ale malt: 2.8 kg (70%)
• Flaked barley: 0.8 kg (20%)
• Roasted barley: 0.4 kg (10%)
• Total: 4.0 kg (100%)

Flaked barley is already gelatinised, so it goes straight into the mash. It adds body and a creamy head. Mash at 65 to 66 °C for 60 minutes. Bitter to about 35 to 40 IBU with an English hop such as East Kent Goldings. Ferment with a clean Irish or English ale yeast at 18 to 20 °C. The finished beer should be black, dry and roasty, at around 4 to 4.5% ABV.

Indian water suits stout

Dark grains are acidic. They pull mash pH down. With soft water, a high share of roast can push the mash below the ideal 5.2 to 5.6. With hard, alkaline water, the roast acidity balances the alkalinity nicely.

Much borewell water in India is hard and high in bicarbonate. That is awkward for pale lagers but well suited to stouts and porters, which is part of why dark beers developed in hard-water brewing cities. Measure the mash pH on your first brew. Our guide to roasted malts covers how different roast levels change it.

Smoothing out the roast

If your stout tastes too harsh, there are a few fixes before you change the recipe:

• Add the roasted grain at the end of the mash rather than the start.
• Swap some black malt for a dehusked roast malt, which gives colour with much less bite.
• Check your water. Very soft water plus heavy roast can taste sharp and acidic.

Time helps too. A stout that tastes sharp at two weeks often rounds out after another two or three weeks of cold conditioning, as the roast edges soften and the carbonation settles. Taste before you rewrite the recipe.

Fresh roasted grain also matters. Keep it sealed and away from humidity. Our guide to the barley malting process explains how roasting changes the grain.

Where to go next

Once you understand roasted barley and black malt, you can design stouts on purpose: dry and coffee-like, smooth and chocolatey or big and imperial. That skill, balancing roast against base and caramel malts, is the heart of grist design.

Your first step: brew the dry stout above and taste it against a commercial dry stout to see how close the roast character comes.

Common questions

What is the difference between black malt and roasted barley?

Roasted barley is unmalted and tastes coffee-like and dry. Black malt is malted and tastes sharper, with a burnt and ashy edge.

How much roasted barley goes in a dry stout?

Classic Irish dry stouts often use around 7 to 10% of the grist.

Does roasted barley need to be mashed?

It has no enzymes, so it relies on base malt in the mash. Its colour and flavour come out readily in hot water.

Is hard water good for stouts?

Yes. Dark grains are acidic and balance alkaline water, keeping the mash pH in the right range.