Beer School : Lookin’ for some hot stuff
WORDS: Louise Crane
Thursday 08 March 2018
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Amber, chocolate, crystal. Not the makings of a decadent truffle an ambassador might spoil you with, but the descriptive names given to some of the truly fundamental ingredients of beer: malt. The huge variety in beers available owe a debt to the huge range of malts available, a debt that’s repaid with every sip of delicious beer. What exactly is a chocolate malt though? You’d be forgiven for thinking it’s something to do with cocoa, but in this case both you and Ferrero Rocher’s ambassador would be disappointed. The name refers to the colour, obtained by kilning and roasting malted barleys to an exact specification. Each type of malt has a personal heat treatment that readies the barley for fermentation, and it’s these specific techniques that give us a vast array of malts, from Pale Ale to Black Patent. We interviewed master malster George Irving at Muntons Malt in Suffolk, one of the five major maltsters in the UK, to explore the work that goes into making them.
To start at the beginning (since it’s a very good place to start), raw barley is germinated, which means it is encouraged to sprout by a process of wetting, drying, and warmth. The seed has its own energy stores bundled up in starches, and these are released as usable sugars during germination to power the developing seed. Is When rootlets, or ‘chits’ appear, it’s time to halt the process by drying, before all the vital fermentable sugars are used up by the growing plant. As George explains, “ The germinating barley (known as green malt) is first turned to ensure there is no matting. Next it’s moved by conveyors and elevators directly from the germination vessels over to the kilns for the next stage of malting, called kilning. Darker colour malts such as Munich and Melanoidin malts are also given a careful extra stewing before moving over to the kilns.” During kilning, heated air passes through the bed of malt to drive off moisture, at temperatures of between 65*C and 100*C.
What happens next depends on the time of malt desired at the time. We all know that the longer we heat something, the browner it gets. This is thank to the Maillard reaction, and it explains your golden brown toast, crispy fishfingers and singed sausage skins. This particular reaction, our resident chemist Adam McCudden explains: “The Maillard reaction is what happens between amino acids (the building blocks of proteins) and certain sugars. The free aldehyde or free ketone group of these ‘reducing’ sugars reacts with the amino acids, which results in new compounds that are, basically, pretty tasty. It’s the type of amino acid that determines the flavour, and all these are found within the barley itself. There are many possible compounds that can be produced (and so many different flavours), some of which are brown nitrogenous polymers and melanoidins, also brown. The reaction requires heat, so the heat of kilning is vital for the tastes and aromas of beer.”
George Irving explains how these different colours and flavours are obtained: “For standard malts, colour is mainly determined by the time and temperature of kilning. We kiln batches ranging from 30 – 300 metric-tonne-seconds (MTS). Lager malt would typically be kilned to around 85C (air on temperature) - with the exception of lager malt which is high in dimethyl sulfides (DMS) where the final air on kilning temperature will be 65C. Ale malts may reach temperatures up to 100C.” It as after kilning that green malt loses its newborn status and becomes, simply, malt.
The next stage on barley’s ride through the malting factory is roasting. The batches here are much smaller, usually between one and five MTS, since they have to fit into a roasting drum. And they are hot. “The air on temperatures can reach a maximum of 230C,” says George. “The actual temperature depends on the desired final colour of the malt. Another factor that has a major impact on the colour is the green malt’s moisture content. This can range from 45% to dried malt or barley that will attain a Chocolate or Black Malt , the darkest of malts produced.”
Anyone who has studied the ingredients label of beer will know that barley is not the only grain used in brewing. So it just barley that goes through the kilning process? “Barley is favoured as it contains a husk which helps to protect it during malting, plus the all important enzymes. But the other grains such as wheat, oats, rye, millet and quinoa (particularly common in traditional African beers) are malted too, so will be kilned in much the same way. The kilning of these differs only slightly in terms of time and temperature and how the grain is handled . There would be more variation in the earlier steeping and germination,” explains George.
It appears there are so many variables to attend to, malting must be like spinning plates. There’s moisture, temperature, maturity of the raw material, and measurements in all sorts of units, some created specifically for the beer industry. The malting process never stops, it’s a continuous flow from one process to the next, as germination leads to kilning and roasting, which then goes into the mill to crack open the grains to further reveal their fermentable sugars, and onto the mash tuns to finally make some alcohol. “No day is the same. It’s generally accepted that it takes seven harvests for a maltster to come experienced in all the vagaries that the crop can cause. He or she will regularly be on call regardless of the time of day. It is essential to be hands on in the daily approach,” says George.
Not only that, but the maltster has to wear many hats. “We will be involved in budgeting, HR, planning and monitoring the process, dealing with brewers and distillers... plus numerous malting suppliers and regulatory organisations.” Not to mention talking to the press! Sounds like very hard work, but many maltsters in the industry are “lifers”, employed for over 40 years in the industry. George himself has been in post for xx years and has the accreditation of ‘master’ from xxx.
As a global supplier, Munton’s malt goes to the largest to the smallest brewers, selling just one sack or hundreds of tonnes. Distilleries, of course, require malted barley too. As an extract, it is very popular with home brewers. But it’s not just alcohol that is malt’s final destiny. Transformed into flakes and flour, malted barley is important in industrial baking, particularly bread, and the delicious, squidgy substance that is malt loaf. For a little perspective on how much malt needs to be produced, Muntons Malt sells over 210,000 tonnes of malt annually, and there are four other companies doing the same. That’s 2758 male African elephants.
So there it is. The magic of heat transforms sprouting seeds into a rainbow of malts (if rainbows were sort-of beige), their crystallised sugars ready for action and a hot, hot bath. We have the skill of maltsters like George Irving to thank for the choice of malts available to brewers, and the range of ales, beers, lagers, porters, and stouts that we imbibe.Now I’m off to have a bottle of Vollenhoven Extra Stout and chase it down with a certain, spherical, hazelnut chocolate.
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