Crystal malt colour and the sweetness it leaves

Crystal malt is mashed inside the husk

Ordinary malt is dried gently so its starch and enzymes survive for the mash. Crystal malt takes a different road. The maltster takes wet green malt and stews it in a closed drum at mash temperatures, roughly 64 to 72 °C. The malt's own enzymes turn the starch inside each kernel into sugar while the husk is still on.

The drum then heats the grain further to dry and roast it. The sugars caramelise and set into a glassy core, which is where the name comes from. Bite a kernel of pale crystal and it crunches like a boiled sweet. That conversion has already happened, so crystal malt brings no useful enzymes and needs no mashing. It can be steeped and still give up its colour and sugar. Our guide to crystal and caramel malts covers the wider family.

Colour decides the flavour

The same process stopped at different points gives very different malts. Rough bands, in EBC:

• About 20 to 40 EBC: light caramel, honey and a soft sweetness. Used for body and a little colour in pale lagers and golden ales.
• About 60 to 150 EBC: toffee, caramel and a rounder malt sweetness. The classic amber and pale ale range.
• About 150 to 300 EBC: raisin, dried plum, burnt sugar and a drier, slightly bitter edge. Used in brown ales, porters and strong dark beers.

A common mistake is to treat a dark crystal as a stronger version of a pale one. It is a different flavour. A pale ale built on 120 EBC crystal and one built on 40 EBC crystal at the same colour taste like different beers.

Where the sweetness comes from

Crystal malt adds sugars and dextrins the yeast cannot fully ferment, plus caramel flavours the tongue reads as sweet. Both push perceived sweetness up. The first raises final gravity a little. The second makes the beer taste sweeter than its gravity says.

How much crystal shifts final gravity is often overstated. Mash temperature, yeast strain and fermentation health usually move attenuation more than a few percent of crystal does. If a beer finishes sweet and heavy, check the mash thermometer and the pitch before blaming the crystal.

Bitterness is the counterweight. A beer with 15% crystal needs more hop bitterness to balance than the same beer with 5%. The bitterness to gravity ratio (BU:GU) that worked in your pale base beer will taste flabby once you add a lot of caramel.

How much to use

Most beers sit between 3% and 15% crystal in the grist. As a working guide:

• Pale lager or golden ale: 0 to 5%, light crystal only.
• Pale ale or bitter: 5 to 10%, often a single medium crystal.
• Amber, red or brown ale: 10 to 15%, sometimes a blend of two colours.

Above roughly 15 to 20% most beers turn cloying, with a sticky finish that tires the palate. For a 20 litre amber ale, try 4.2 kg pale malt (84%), 0.5 kg 60 EBC crystal (10%) and 0.3 kg 150 EBC crystal (6%). That gives 5 kg in all, a rich toffee middle and a firm red tint. Our guide to brewing an amber ale with crystal malt takes it further.

Crystal ages fast in a warm market

Beers heavy in crystal malt show their age readily. In warm storage the fresh caramel turns towards sherry, dried fruit and wet cardboard. In India, where kegs and cans can sit at 30 °C or more on the way to the bar, a crystal-heavy amber ale has a short good life.

Keep crystal percentages modest in beers that will travel. Low oxygen pickup in packaging and cold storage matter more for these beers than for a lean pale lager. Store the malt itself sealed and cool too. Crystal malt pulls in moisture fast in monsoon humidity, goes soft and loses its crisp caramel character.

Taste the malt before you design with it

Spec sheets give you colour and extract. They do not tell you how two malts of the same colour differ in taste. They do. Before using a new crystal, make a hot steep: about 50 g of crushed malt in 400 ml of water at 65 °C for 15 minutes, then strain. Taste it next to your current malt. You will notice differences in sweetness, roast and dried fruit within seconds.

Matching crystal colour, sweetness and bitterness on purpose, rather than by copying a recipe, is the heart of grist design. It gets easier when you understand the chemistry behind each malt.

Your first step: make hot steeps of every crystal malt in your store and taste them side by side with your brewing team.