Malt: getting the grist

The Reinheitsgebot would have you believe that the raw ingredients needed to brew beer are very simple. On paper, it’s just water, barley, and hops (and yeast, they begrudgingly conceded in 1993). Basic raw materials transformed through the magical process of brewing into our beloved tipple of choice. Or so it seems.

After ICIP’s trip to Stocks Farm in April, we learned that the humble hop is anything but simple. There were lupulin glands, alpha acids and myrcene levels to learn about, extensive scientific breeding programmes being developed and multi-million pound hop picking machines chugging away beyond the hop yards. We were amazed by our own ignorance about what we thought was a simple component of the brewing process, and it made us wonder where else our knowledge fell short.

Enter the Maltsters Association of Great Britain (MAGB), who kindly organised for us to tour Bairds Malt plant in Witham, Essex. This is the largest plant under the Bairds umbrella, producing nearly 50m tonnes of malt a year, mostly buying in barley from the “granary of England”, East Anglia. We meet with MAGB’s Executive Director Colin West, who is going to be our teacher and tour guide for the day. It soon becomes apparent that we have a lot to learn.

DSC_0002Giving us a bit of a background to the UK malt industry, Colin explains that we’re pretty unique for having the two big markets of beer and whisky: “whisky around the rest of the world is usually made from other things, whereas Scotch legally has to be made of malted barley, so it’s an important market.” Malting has historically been an active and productive industry in the UK, and the MAGB itself is around 180 years old. “When it was founded, every village and every town would have had a maltings or two, and the 1,800 members were only a fraction of the malting industry in the UK at the time,” says Colin. “There was a malt tax in place and the government were imposing more and more regulations, causing disruption to the production process, and the maltsters were pretty aggravated about this. It took them a while, but they managed to get rid of the malt tax by the early 1880s.”

While we are aware of the decline in British hop farming over the years, we are still surprised to hear that despite the recent beer boom, the malting industry has not grown in recent years. “The maltings sector in the UK is almost exactly the same size as when I joined the industry in 1976,” says Colin. “I remember in those days we grew 10m tonnes of barley in the UK, and 2m tonnes went for malting and the rest went for animal feed. Now we grow about 6m tonnes, 2m still goes for malting and a smaller amount goes to animal feed because they use wheat for that more now. There’s been rationalisation: smaller plants have closed, we’ve got fewer companies than we used to have, and we just haven’t expanded.”

But in the same way that Germany and the US have overtaken us in hop-growing, our continental cousins have been expanding rapidly in the grain business. “The two largest malting companies in the world are now French: over the last 40 years the French have grown between ten- and twenty-fold,” says Colin. “A lot of the grain trade marketing in France was run by farmer’s cooperatives, which were strong through CAP after the common market was formed in the 1950s. They realised that milling wheat into flour or malting barley were ways of adding value to the grain, so they took a long-term view and invested in malting capacity. They own companies all over the world now. I don’t think we could grow quite that big, but it’s a bit of an oddity that we’re exactly the same size after all this time.”

DSC_0003This seems strange when the brewing scene at least appears to be booming globally, but according to Colin total beer consumption is falling despite the proliferation of new breweries. And while cask ale is the winner – growing from 9% to 12% of the market – it’s the big name lagers that are noticing the drop off. He also points out “in some markets they use other materials. As an example, Budweiser in the states has 40% rice in it. Once you’ve got that rice in, and you’re a brand the consumer knows, you don’t change it back at that point. At that point, the customers know what they want.”

The maltings industry is having to adapt to accommodate the new breed of microbrewery, putting in packaging lines to produce 25kg sacks of product rather than sending off 29 ton lorries, and installing mills to provide grist for breweries who cannot mill their own malt. “What Bairds has done recently is set up an autonomous subsidiary, Brewers Select, which mills separately in order to service the craft market. It doesn’t change the way anyone services the big market, they just have to service the smaller guys too,” says Colin.

WIthout further ado, we’re thrown into the science bit. Colin starts us off with Beer 101: at the brewery, enzymes in the malt break down the starches into sugars, which the yeast uses to make booze. The barley’s job is to provide nutrients for fermentation. The reason we malt the barley is that in it’s raw state it doesn’t have the enzymes it needs.

We move on to a very complicated cross-section of a barley grain. This is a seed, and there is an embryo of a new barley plant inside as well as the endosperm, which is a food store which will feed the plant until it has leaves and can get energy from the sun.

In short, and avoiding a lot of jargon – the energy in the endosperm is mostly starch contained in rigid cell chambers. When the seed germinates the embryo sends out a signal asking to be fed, and enzymes are produced which break down the cell walls to release the starch and begin to convert the starch into sugar. This has to be kept in check because the maltster wants to deliver these starches and enzymes to the brewer, so the process cannot be allowed to go too far. This is why although you may see rootlets on barley when it is being malted, you never see any shoots. Indeed, in ye olde times the maltsters would sometimes judge whether the malt was ready by breaking open the grain and seeing how far the shoot had grown inside before making an appearance.

DSC_0017Basic knowledge acquired, we don hi-vis vests and hard hats and intrepidly set off to follow the grain’s journey around the site. We begin at the barley intake, where they do quality control on the incoming lorry-loads of barley. Gatekeeper Maggie explains: “I use an automated scoop to take a representative sample. I can check some things visually – I want to make sure it’s the right  variety and I want to make sure I’ve got malting barley and not another type of grain. I also look for a fungus called ergot, which is hallucinogenic, so we don’t want to see any of that in the barley!” She gleefully shows us a little pot of the offending substance, conspiratorially adding: “this is our personal supply!”

“If you see one piece of ergot you’ve got to reject the whole truck,” says Colin. “The maltsters have rejected about one load in 150.” This isn’t the only instant rejection, as Maggie explains: “There are insects that would damage the grain by eating away at the embryo inside, like weevils. which are tiny. If I find any one of those – alive, dead or a body part – it’s an instant reject. All would suggest there had been an infestation somewhere along the line.”

After this initial inspection, things get more technical, and Maggie has a proper mini lab in her office. “I look for moisture and nitrogen levels using the infrared machine. There’s also a machine which gives us a breakdown of how many whole corns, broken corns and extraneous material like husks there are. If it falls outside the parameters we take a bit of a claim against the cost, but if it’s way off, we start rejecting the lorries.” And there’s more… “That is a grain stain machine – we cut a corn in half to reveal the embryo and the machine stains it bright red. As it degrades or starts to grow, it becomes paler to the point of being white. If it’s white, it’s dead, so if you haven’t got a red embryo, we can’t do the malting process. We look for a 98% parameter on that and we reject on anything less.” It’s beginning to sound like some sort of barley X-Factor. “It is frustrating, and ultimately it’s the final customer, the beer drinker, that’s paying the extra transport cost for the rejected load,” says Maggie. “So if we can work with the merchants and farmers to make sure everything’s accepted, that suits us. It keeps the maltsters’ costs down which helps when the breweries are negotiating to get the malt price down. But we could be losing half of what comes in, we just happen to be extremely good at it!”

DSC_0009As we move towards the huge conical steepers, Colin points out Bairds’ water recycling plant. Bairds is only the second maltings site in the country to recycle its water. There have been problems with attempts to do this in the past with remnants of materials in the water used for steeping which meant that it could not be reused, but treatments have been developed to solve this issue. “The expectation is that processing waste water will become more expensive in the future,” says Colin, “so this will make a huge difference. All maltings use fresh, drinking quality water for the steeping. At Bairds they also use a barley washer to pre-steep and to get dust off the grain.”

It can take almost two hours to transfer a batch of grain into the giant steeping conicals. Bairds has six of these, each holding 35 tonnes of barley. The reason the capacity is split is to help spread the hydrostatic pressure on the grains more evenly to encourage it all to accept moisture and germinate. “Each batch is four thousand million grains of barley and the aim is to make sure each grain sees the same conditions as the next,” says Colin. “It’s impossible… but you try your best!”

DSC_0033When the barley goes into the steeper, it is usually at about 12% moisture. It is then covered in water, drained and covered again, and in between these wet periods it also has ‘air rests’ where it is allowed to breathe, absorb some of the moisture and begin its biochemical processes. Air is also bubbled through the water for a few minutes every half hour while the grain is steeping to keep it aerated. “When the maltster takes the batch out to steep, he’s looking to raise the moisture content to about 45%, that persuades the embryo that it’s been rained on and that it’s time to grow into a baby plant,” says Colin. This process takes two days. “By the end of those two days, the respiration rate has gone up quite a bit and each grain is generating heat from its own metabolism,” says Colin. “In bulk that’s quite a lot of heat, so it’s important the maltster can move that into an environment where he can accurately control the temperature.”

This marks the beginning of the second stage – germination. “In the germination vessel, the whole point is to keep in at a constant temperature,” says Colin. “If it was left in a steaming heap, it would go well above 60°C. So we both blow air through to keep the temperature down but we also keep up humidity so that it doesn’t dry out. The aim is to make the air 100% humid.”

DSC_0057Traditionally the malt would be spread in a thin layer on the floor and raked over by hand. Today the grain is still turned, two or three times a day, but it’s now done mechanically by a boom that sweeps around the circular vessel. “The goal is to make it flat,” Colin points out. “The resistance at 1m is different from that at 1.1m so you’ll get more air coming up and it’ll affect the grain differently. Obviously, as all the grain moves around, it’ll average out over the 4 days it’s in here.

From around of 3 days onwards, the rootlets realise there’s no extra nutrients out there, so they start thinking about withering.”

During the four days of germination the enzymes are produced, the cell walls begin to break down, and the malster has to stop the process at the right time. “There’s not much the maltster can do during this process to see how it’s going, so he’s relying on experience,” says Colin. “They are constantly testing the end product in the lab, so they can tweak the next batch to correct anything that didn’t go as well last time.”

DSC_0060Using a long cup on a pole, Colin fishes out some grains from both the two- and four-day-old batches of germinating barley. “If you pinch off the end of the corn to get rid of the embryo, then squeeze out the contents and rub it between your fingers, you can feel the texture,” he says, passing us a four-day-old grain. The contents comes out like toothpaste. “That’s perfect. That means the protein and cell wall are gone and what is left is pure starch.” We repeat the process on the younger grains, and the contents are much firmer. “It’s coming on, it’s just not quite as smooth. The maltster will do maybe six to ten corns from different places to get an idea,” Colin explains.

The final stage is kilning, which stops the germinating process. “We started with 210 tonnes of barley, we added 80-90 tonnes of water, and then in the kiln we’ll drive off the added water but also bring down the moisture content from 12% to 5%, so we’re evaporating around 100 tonnes of water!” says Colin as we enter the sweltering kiln. “It has to be a gentle drying process because the enzymes are temperature sensitive, even more so when there’s a lot of water around.”

DSC_0073Below the drying grain is a chamber about 6ft high which helps balance the pressure: “what you don’t want is the grain nearest the fan to get more airflow, so if the fan blows into a big area it equalises the pressure across the bed so the air comes up evenly,” says Colin. “So you start between 50-65°C, and because moisture is evaporating the grain is cooler than that, around 25°C. After about 12 hours of blowing the air through, the temperature in the grain starts to increase, but because the moisture has reduced to about 15%, the enzymes are more stable, so it’s safe to bring up the temperature.” Coloured malts can be made in the same kiln by upping the heat, and the maltster ends up with a grain with a moisture content of about 4-5%.

At this stage the little rootlets (or ‘culm’) on the grains drop off, and they are collected to be sold for animal feed. Astonishingly, they contain more protein than the original raw barley, and this is all extra income for the maltsters – very important given the huge outlay in energy costs. “Traditionally, everything was manual,” says Colin. “Shoveling, barrows, raking, water it with cans, feel it by hand… but now you could run this whole site with just a few people. It used to be labour was the second highest cost after barley, but now energy is far higher. It’s mostly heat, but it’s also electricity on driving the fans.”

DSC_0086The final stage of the malt’s journey is the roasting plant. “At Witham they have a roasting plant so they can roast in much smaller batches than in the kiln. That takes 210 tonnes of barley whereas the roaster takes just two.” Each type of malt gets a different treatment in the machines, which are based on the same technology used for roasting coffee. “You take white malt and then take the temperature up to about 180°C for brown malt and 220-230°C for chocolate and black malts. This makes it very dark and bitter,” explains Colin. “Colour is the critical control, and the guys here have got decades of experience. They take samples; and at the end of a darker roast they’ll be doing that every few minutes because the end point is critical. They’ll grind some into a flour and compare them against standardised samples which have been tested in the lab.”

The oddball is crystal malt, which is treated a bit differently. “You take green malt, direct from germination, and raise the temperature up to 65°C, which is the equivalent of the brewer mashing it. Each grain is its own mini mash vessel – it’s got a moisture, enzymes and starch in there, so when the enzymes break the starch down so you end up with a liquid package. It’s like liquid caramel inside. The temperature is increased up to about 130°C and the moisture is driven off, and that’s what gives you the lovely toffee character of the crystal malt.”

Our heads spinning from our quickfire introduction to the world of malting (and the ever pervading scent which is making us crave Horlicks and Maltesers), we remove our hard hats and decamp to The White Hart in Witham to enjoy malt in its most delicious form – a pint.

Just as after our hop farm visit, we’re amazed at how much history, technology and science has gone into this basic building block of our favourite drink. We’re glad we took the time to expand our knowledge – the next time we visit a brewery and they casually make reference to their mash tun, we’ll understand exactly what’s going on in there, why, and what all the work that had already gone into those little grains.

Now, someone, please… get me those Maltesers.




2 thoughts on “Malt: getting the grist

  1. Pingback: News, Nuggets & Longreads 27/09/2014

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