Grain Cooking

Thursday May 16, 2024

If you want to make whiskey, any whiskey, you have to first make beer. Brandy is made from wine, rum from cane sugar but whiskey always has to be made from beer. Now, depending on what sort of whiskey you want to make and how you want that whiskey to taste, it will depend almost entirely on the grains you use.

Single malt whiskey, as the name implies, has malted barley at its core. The same is true for Irish whiskey. Yet American whiskeys, such as bourbon and Tennessee whiskey, have corn (maize) as their main ingredient. Canadian whiskey uses a variety of grains and again as the name implies ‘blended Scotch’ uses a mixture.

Now you can’t make a beer or whiskey ‘mash’ from just the grain alone. To ferment beer, you also need yeast and a source of sugar for the yeast to feed on. However, once you have that food source, the yeast can consume the sugar which produces alcohol and CO2, and hey presto, you get beer.

But how do we get sugar from cereal grains you may ask yourself? Well, the simple answer is to ‘cook’ them. But this is far from the whole story. Different grains require different processes to extract the sugars we need for fermentation. Malted barley is by far the easiest and corn is arguably the most difficult. Right about now, you may be wondering, what exactly the term ‘malted’ actually means! You’ve probably seen the term in the title of Malteaser sweets and if you’ve ever tasted them, then you know what malt barley tastes like. Simply put, malting is the process by which grain is artificially germinated to produce an enzyme called ‘alpha amylase’. Once the grain sprouts, it’s then heated to halt the germination and preserve the enzymes that have been produced. Under natural circumstances, these enzymes would be used in the growth of the new seedling, but its also rather handy for converting starch into simple sugars for fermentation.

Now, I’m not sure who it was, how they came about this process or what they thought they were doing at the time, but whoever discovered this process, was an absolute genius. If you heat up water to 67ºc and steep the malted barley, you convert the starchy barley ‘soup’ into a sweet beer or wert that can be fermented into a beer.

Making beer from corn on the other hand, is a lot more work. it could be said that corn based whiskey, is the most difficult spirit you can try to make. It is possible to ‘malt’ corn but it isn’t available commercially in quantity, as the process is reportedly much harder than that of malting barley. Where there is a number of Scottish distilleries that do malt their own barley, I’m not aware of any distilleries anywhere that takes the time or trouble to malt corn.

So, if the majority of grain used in making bourbon is corn, how in the world do they do it?….
It’s a multi step process. Once the corn has been sufficiently cooked or boiled to extract the enzymes we talked about earlier, that are produced in the malting process, are then used to convert the corn starch into simple sugars. Once the starchy soup has been cooled to below
30ºc, so as not to denature the alpha amylase enzyme, the ‘malt’ is simply stirred into the mix. What happens then, is truly a miracle of nature. The gloopy, thick, starchy corn ‘soup’, instantly releases and thin’s as the enzymes convert the starch to sugar. This process can only happen because of the malt’s ability to convert several times its own weight in corn (or other grains such as rye). This ability is called the ‘diastatic power of the grain’. Simply put, its the measure of the ability (in degrees Lintner per pound of grain), to convert its own starches into simple sugar.

So, all in all, whiskey making is a lot of hard, dusty, hot and messy work. I think you really have to love it, to do it and to do it well. It’s a good job that I really love my work at Penrock Distillery. Every day, every batch and every cask is a challenge, but it’s a challenge I really love and I can’t wait to see what each challenge ultimately produces.

Other articles about our Whiskey, Rum and Spirits

Our jounal about Whiskey, Rum and our process and how we do it the old fashioned Tennessee way

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