Malting for Distilling

Malted Barley’s Other Path

Written by Mark on May 4, 2017

As home brewers, when we think of malt, we think of beer. Most of the world’s barley that is malted will indeed end up as beer, but there are several other industries that rely on malt. People are generally surprised to hear that malted barley flour makes its way into baked goods and cereals, malted milk balls and maltshakes. And while it shouldn’t surprise us, barley malt is also the main ingredient in another drink that has experienced a major surge in popularity: single malt Scotch whisky.

In fact, Scotch whisky has gotten so popular that the distilling industry in the UK has heftily outstripped the brewing industry’s use of barley malt.

Pie chart of UK malt production

Image from UK Malt

I usually stick to beer, but I’ve had whisky on the mind recently for a couple reasons. One, I’m taking a trip to Scotland later this month, which has me excited by the prospects of sampling some amazing scotch in its place of origin. Secondly, Picobrew, the leader in automated home brewing appliances, just announced the release of their new gadget, the PicoStill.

Of course, home distilling remains illegal on a federal level, despite the best lobbying efforts of the Hobby Distilling Association. Picobrew assures everyone that unless you have gone through the rigorous distillery licensing process, the PicoStill is meant to be used to extract hop oils, not spirits. Surely, no home brewers will be tempted by the perfectly good still sitting in their basement…

Anyways, this article is not about home distilling: instead I’m exploring the differences in the use of malt in brewing and distilling, with a focus on single malt Scotch whisky. Here’s to the versatility of malt!

Distillers are A Lot like Brewers

Just as commercial brewers are split between all-malt and adjunct brewing, distillers also identify themselves by their relative use of barley malt in their spirits. Pot distillers are the purebreds: they make single malt whiskies, which uses malted barley as its only fermentable ingredient. Grain distillers, on the other hand, use only a small portion of barley malt to provide the enzymes to convert their other ingredients, which contributes up to 80-90% of the starches.

The ingredients that make up the bulk of their recipe define what the whisky is called. Bourbon, for example, must be mostly made of corn. Irish whiskey (they insert the e in whiskey, and Americans have copied this) is 40-60% unmalted barley that is finely ground, and the remainder is malt, plus wheat or oats.

But Scotch is like Champagne

To be called single malt Scotch whisky, there are specific requirements to meet. As champagne has to be made in the Champagne region of France, scotch has to be distilled in Scotland. It must also be made from 100% malted barley, at a single distillery, and it must be aged at least three years, though they’re generally aged much longer.

Single malt scotches pick up the local character during the long barrel aging process, for example, taking up a salty flavor at the oceanside distilleries. However, 90% of the scotch market is made up of blended Scotch whiskies, a different category altogether, which are combinations of multiple distilleries’ spirits to create a more balanced flavor.

The popularity of the blends in the late 20th century also bolstered the single malt market by bringing international acclaim to Scotch whisky. Distillers have been able to create a luxury brand that is both highbrow and rustic, and consumers will pay top dollar for it.

Classy whisky

Who could say no to that?

Making Whisky is A Lot like Making Beer…At First

Scotch whisky is made of malt, yeast, and water, the same base ingredients as beer, with the exception of hops. And the distillation process starts in the same way as brewing, with the exception of the hop boil.

First, the barley malt is mashed in a multi-stage process to extract the absolute maximum of sugar from the grains. After each mash, the sweet wort is drained and replaced with hotter water for the next mash to extract all the more sugars.

Instead of bringing the wort to a boil and destroying any remaining enzymes, it is cooled after the mash and pitched with yeast. This is usually a blend of brewer’s yeast for aromatic flavors and distiller’s yeast for a rapid and robust fermentation. During this period, enzymes are still at work breaking down sugars to produce even more alcohol. After 48 to 96 hours of primary fermentation, the wort (or wash, in distiller’s terms) has reached 6-10% alcohol content. If the distiller stopped there, they’d have a very bland, colorless, unhopped beer.

Fortunately, they don’t stop – they dive right into the distillation process. This is where things get crazy. The wash still (see picture below) takes the fermented wort and heats it up to the point where the ethanol will evaporate, which happens at 173 F. The alcohol vapors travel up the long skinny neck of the still and then down through the condenser to become liquid again. After 4 hours, all the alcohol should have evaporated, along with some other stuff, and collected in the low wines receiver.

Copper Pot Stills

Copper Pot Stills

That was just the first round of distilling. The alcohol content of the low wines is only 25%, so the distillation process must happen again in the spirit still. The heating is done more carefully this time, slowly over 8 hours. The first bit of alcohol to evaporate is too harsh and the last bit too weak, so it is only the “middle cut” that makes it through the spirit safe and into the spirit receiver, at an alcohol content of 67.5%

That’s distilling in a nutshell (more thorough guide with helpful diagram here). I suppose I should also mention that after distillation day, the spirits go into an oak cask to mature for like 12 years. But that’s an unimportant detail…Just kidding, almost everything that gives the whisky its unique distillery character happens in the barrel. Color and flavor develop very, very slowly over those years as the distiller waits patiently for the day it can be bottled and sold for a lot of dough.

Image of whisky aging barrels

Malting for Distillers

So after the whole distillation process, the flavor just comes from a wooden barrel? Well, not exactly. The shape of the stills can have an impact on the finished character of the whisky, as a longer neck separates out more flavor compounds, leading to a purer, smoother whisky.

Some distillers also point to flavor differences based on the malt they use, but this doesn’t get nearly as much attention as it does in brewing. Unlike a beer that may have 6 different types of malt going into the grain bill, single malt scotch is made with only one type of malt, as the name suggests.

The main concern for distillers is that they get malt they can squeeze a ton of sugar out of, which translates into the most alcohol possible. This means no specialty roasted malts – they want the lightest of base malts.

With that goal in mind – MORE ALCOHOL! – maltsters have a different malting process when producing for scotch distillers. They shoot for the highest extract by letting the barley germinate for longer to ensure maximum modification of the starch. Then they follow a kilning schedule similar to that of a Pilsener malt: low heat for minimal color development or enzyme breakdown.

For that reason, distiller’s malts are just supercharged with the enzymes to convert every last bit of starch into booze. This is especially important for grain distillers, who, as mentioned, use an unmalted grain to provide the bulk of the starch and then a tiny amount of malt to provide the enzymes to convert it all. Similar to adjunct brewers, grain distillers need through-the-roof diastatic power in their malt, and they get it from six-row barleys that are high in protein.

Peating: The Smoked Alternative

Despite the relative blandness of distiller’s malts, there is one key feature that makes them stand out: their peatiness. Instead of distinguishing malt types by how much they’ve been kilned/roasted, distillers set malts apart by how long they’ve been exposed to peat smoke.

This tradition owes its origins completely to the landscape of Scotland, where there are very few trees. The Scottish people instead turned to peat as their primary fuel source, which they harvested from their infamous peat bogs. The regional differences in peat composition create a rather distinct peat flavor in the whiskies from the Highlands vs the Isle of Islay.

Image of peat

Peat bricks cut and laid out to dry

Traditionally, malts were kilned entirely over a peat fire, which lent that harsh smoky flavor that we’ve come to know and love (or hate) in our scotch. Nowadays, there are much cheaper fuel sources to use to heat the kiln air, so the peat is burned in a separate furnace and the smoke is directed into the kiln airstream and through the grain.

Peating is not an easy thing to master, as the peat burns rather unevenly, so peating is still considered something of an artform. It is much easier to heavily peat your malt, so maltsters often mix this with unpeated malt to get something in the middle.

If you’re interested in peating your own malts, it can be done relatively simply. The reek of the peat is taken up most effectively when the grain has some surface moisture, so the peat smoke should be added nearer to the beginning of kilning if you’re malting, or after soaking some pre-malted barley if you’re not. Just don’t go and distill that malt or you’ll be in trouble with the law!

Breaking with Tradition

The origins of whisky distilling date back to the 15th century in Scotland, and while the industry has changed significantly, they still strongly hold value in tradition. This is most evident in their marketing, while often absent in their processes.

There was a time where every Scottish distillery had a floor malting operation to supply their stills. As the malting industry moved away from this human-powered standard, the distillery’s floor maltings shut down one by one, and they trucked in malt from one of the big malthouses that had consolidated and survived. Seven distillery floor maltings remain, and one of these, Benriach, was recently recommissioned after being mothballed decades ago.

Image of peat

Like the abandonment of the malting floor, the iconic pagoda kiln roof is no longer used, though most Scottish distilleries still feature them in their marketing

The floor maltings claim that there is a distinct character to their malt that can’t be replicated on an industrial pneumatic scale, but there are many whisky experts who beg to disagree. Most of the industry actually claims that floor maltings are inferior, as they lack the precise climate control of the big malthouses. It’s hard to pick a winner in this debate as they’re both arguing the side that supports their own interests.

The New Scotch, but American

Over on this side of the Pond, there are a number of craft distilleries who are throwing everyone for a loop and making the kind of single malt whiskies that are so deeply associated with Scotland. Classic Americans: taking someone else’s tradition, putting their own spin on it, and calling it new.

In this case, they really are adding an interesting new layer to the single malt tradition. As mentioned before, the barrel aging process contributes a flavor that reflects the barrel’s surroundings, so these American distilleries are making single malt whiskies with the unique character of the Rocky Mountains or the plains of Texas.

A few of these distilleries also operate malthouses, as so few of the Scottish distilleries do anymore. Corsair Distillery, out of Nashville, TN, malts their own grain and smokes it with peat, beechwood, and cherry wood to make their award-winning Triple Smoke. So while they pay an homage to the single malt Scotch tradition, they’re also doing things that no Scots are attempting with whisky.

It’s an exciting time for craft distilling, just as craft brewing is still riding a long wave of enthusiasm. And I’m happy to see that Americans have started to put their mark on single malt whisky and reimagine what it could be.