But before any grain can be distilled there’s a cultivation cycle to be completed in the fields.
It’s traditional for distillers to use winter varieties of wheat and rye, meaning they are sown in the autumn and harvested the following autumn. Meanwhile, spring varieties of barley and corn are used, which are sown in the spring and harvested during the autumn of the same year. Whichever grain is cultivated, the ideal scenario is steady rainfall during the growth phase, and an absence of rain in the month preceding the harvest. Needless to say, the weather is a vital factor, and even within the same State weather patterns can vary greatly.
Corn divides into different types depending on the colour, with the standard choice for distillers being yellow corn.
“In Alabama they begin planting corn in late March, and in Iowa it’s April, as the further north you are the longer you have to wait for the weather to warm up, and the later you plant,” says Brown-Forman grain buyer, Tom Neiheisel.
Rainfall is vital during pollination, typically a couple of months after planting, to ensure that the ears of corn form successfully and the level of kernels is maximised, ready for the harvest in August-early September. Key sources of corn include Kentucky, Illinois, Indiana and Alabama.
Barley is planted in April-May, and depending on the weather shoots can appear within a few days or a few weeks, with the drier climate and drier sandier soils of Idaho and North Dakota an ideal terrain (additional sources of barley include Montana and Wyoming). Typically, the warmer the Spring the earlier the harvest, which can be as soon as August or as late as October.
Wheat can deal with various soil types, from moist to dry, sandy soil, though rye is renowned for coping even better with anything less than its ideal terrain of dry, sandy soil.
“If everything goes according to schedule, winter rye and winter wheat sown in August-September results in plants around a foot high by the time of the first frost, which stops any further growth during the winter.
“Any snow serves to irrigate the grain when it melts, and once the weather is warmer, usually in April, this instigates another growth cycle which continues until the harvest,” says Tom Neiheisel.
Wheat is harvested in July-August with key sources including North Dakota, Illinois, Indiana and Kentucky, while rye is typically harvested in August-September from states such as North Dakota and Minnesota.
“In the last 8 to10 years many farmers switched from rye to corn as rye prices had been so low, while the price of corn was rising, so there’s been much less rye produced of late.
“This resulted in rye prices going up, so farmers could now be looking to plant rye again.
“Everything goes in cycles,” says Craig Beam, Heaven Hill master distiller.
Once harvested the grain can be left in the field to dry, or the farmer can gather the grain in special driers (through which air is blown) to reach a moisture level below 15 per cent. This is vital in order to store the grain safely, initially on farms and subsequently at the distillery, with each harvest generally reaching distilleries the following year.
“We take samples of all grain deliveries for quality checks, as higher moisture levels facilitate the growth of bacterial and fungal infections, and if this happened we wouldn’t distill the grain. We also regularly inspect the grain bins, as even any condensation in the bins can potentially cause infections,” says Ryan Ashley, director of operations, Four Roses distillery.
Corn is indigenous to the USA, having been cultivated by Native Americans. Rye, wheat and barley were cultivated by European settlers, who also brought the knowledge of distilling with them, and began producing whiskey.
Distillers buy malted barley from commercial maltings, located for example in Montana and Idaho. Additionally, there’s a concentration of commercial maltings in Milwaukee, the centre of the brewing industry, which also requires malted barley.
Rye, wheat and corn (which aren’t malted) can be bought on the open market but are usually sourced by a distillery’s grain buyer, direct from farmers or grain merchants, on the basis of contracts which are regularly reviewed and renewed. One advantage of contracts is a supply of grain at the required quality and price.
The incredible growth of interest in American whiskies has a very recent history. It began with cocktails coming back into fashion in the USA during the 1980s, which also prompted greater interest in spirits. This in turn led to more specialised Bourbons being released, such as single barrel styles, providing consumers with more to think about, not only in the USA but internationally. Knowing about brands and production became cool, and visiting distilleries in Kentucky took off in the late 1990s.
“We have visitors from all over the world with in-depth knowledge of production, but they still want to learn more. We’re currently building a new $4 million visitor centre ready for later this year,” says Jimmy Russell, master distiller, Wild Turkey.
Bourbon’s popularity also led to greater interest in other American whiskies, with rye whiskey significantly more popular since the millennium.
Rye whiskey, malt whiskey and wheat whiskey must each contain a minimum of 51 per cent rye, malted barley or wheat respectively, while corn whiskey must contain a minimum of 80 per cent corn. Regulations don’t stipulate which grains should make up the balance.
Each grain contributes an individual flavour profile, though adding malted barley facilitates another vital function. This is because the process of malting the barley allows it to germinate, which activates enzymes, with the barley then dried to stop further growth (corn, rye and wheat aren’t malted).
During the production process the grains are milled, and when cooked in hot water the enzymes within the malted barley promote the conversion of starches contained in the grains into sugars. The resulting sugary liquid is fermented by adding yeast, turning the sugars into alcohol, and creating an alcoholic liquid of 8-10% abv. Once distilled the resulting spirit is aged in oak casks, with a minimum two year aging period for various whiskies.
Brimstone Corn Whisky
Nose: Embers, toastyness, dried herbs, light sprinkling of freshly ground pepper, mellow corn, with underlying oak and toffee emerging.
Palate: Lightly creamy texture. Chocolate, mellow spice and corn take off together, laced with toastyness and subtle underlying dryness, freshly ground pepper and zesty lemon.
Finish: Toastyness, dryness, oak, toffee and fresh pepper.
Comments: It’s all about counter-point, with different flavours balancing and enhancing each other. Adding water makes the palate fruitier and creamier.
Nose: Once you get past the smoky BBQ, there is lots of corn sweetness. Brown sugar, honey, rum soaked raisins. Some herbal notes lurk, sage and thyme.
Palate: All spicy, smoky BBQ goodness. There’s smoked pepper heat and brown sugar sweetness.
Finish: Warm and spicy with some peppery tones.
Comments: A serious whiskey that balances corn sweetness with smoke.
True Blue Corn Whisky
Nose: Fudge, apricots, tiramisu. Corn emerges with a hint of spice, followed by lightly pungent oak and dark chocolate.
Palate: Lightly luscious texture. Fudge, apricots, lemons and dry, underlying oak, hint of toastyness, growing intensity includes fresh pepper, mellow spice, corn and dried fruit.
Finish: Dryness leads with toastyness, subtle chocolate and oak hints, followed by a hint of creamyness and dried fruit.
Comments: A fascinating journey for the palate, from mellow to intense. Adding water increases fruit and spice aromas, the palate becomes creamier.
Nose: Beautiful roasted nut flavours, white chocolate compote, and maple syrup, oak boxes too.
Palate: Sweet and lush with caramel and fudge. Hot buttered corn bread, some fruit too, poached pears and apples.
Finish: Drying with a creamed corn and spiced notes.
Comments: The influence of the corn comes through with all that cream and lush dense mouthfeel.
Original Wheat Whiskey
Heaven Hill Distilleries
Nose: Elegant richness. Honey, gingerbread and orange marmalade, then hints of oak and citrus zest.
Palate: Elegant texture. Vanilla, gingerbread and orange marmalade delivered on a wave of richness, with underlying dryness, then orange notes become juicier, accompanied by zesty lemon, dark chocolate and honey.
Finish: Light dryness leads, then lemons, chocolate and light creamyness emerge.
Comments: Evolves with great poise, like an aria from an opera. Adding water makes the nose and palate fruitier, with the finish marked by a zesty, citrus burst followed by vanilla.
Nose: Hot buttered croissants, then fresh yeasty dough, after proving, Manhattan cherries and allspice. A lemon zest hit and some subtle spiciness.
Palate: Fresh shaved oak, pencil boxes. Hard toffee pennies, orange chocolate and marmalade on toast.
Finish: Gently dries with a zesty note.
Comments: Elegantly balanced with perfect integration.
New York Corn Whiskey (unaged)
Nose: Focussed dried herbs, pepper and light earthyness, followed by spice and corn, with hints of raisins.
Palate: Mellow texture. Sweetness builds gradually, then light spice and pepper emerge at the core, sweetness continues to lead accompanied by hints of corn, lemon zest and raisin, with underlying dryness.
Finish: Freshness and dryness open up, with a garnish of sweetness, spice and lemon.
Comments: A generous, welcoming character that reveals its range in stages. Adding water makes the palate richer, and groups all the details together as a team rather than appearing individually.
Nose: Very herbal at first, then a floral edge, linseed, un-waxed lemon peel and freshly-baked bread on the nose.
Palate: Oily and mellow. Big hits of cereal and spices, some fruit notes, pineapple, apples and pears.
Finish: Crisp and clean.
Comments: Clear corn influence comes through, interesting to have this before it’s aged, shows its character perfectly.
18 Years Old Rye Whiskey
Buffalo Trace Distillery
Nose: Apricots, raisins, oranges, with hints of apples, pears and lemon, then mellow oak.
Palate: Delicate, lightly creamy texture. Indulgent chocolate and apricot. Expands with ripe apples and pears and a hint of underlying dry oak, then creme caramel, raisins and mellow spice emerge.
Finish: Subtle fruityness with growing dryness, then dryness mellows opening the door for oranges and honey.
Comments: Continual evolution provides a series of rewards. Adding water integrates the flavours into a gift-wrapped package rather than a sequence of individual notes.
Nose: Hugely floral with great aromatic notes. Pepper and dusty spices take hold, with hints of citrus zest.
Palate: Fruity and very juicy. A mix of cinnamon, nutmeg, red fruit and custard. Hints of toffee apple and grapefruit peel.
Finish: Long and spiced.
Comments: A stunning, if not epic, whiskey with all the rye influences you could need.