In this nerdy post, you will learn what “malt” it is all about – and why it plays such an important role in the production of whiskey. And as a bonus, I will also dig into why “malting” plays a big role in the flavor and taste profiles differences between American and Scotch whiskey.
For the longest time, I had no clue what “malt” was, what the process of “malting” barley was all about – and why it was relevant. In the process of finding out, another miracle of nature unveiled itself, as many times before, when you dig into the details about whiskey. The word “malt” is derived from “maltose”, which is basically two glucose molecules that are linked together. But more on that topic below.
So, let’s get started ….
When the grains arrive at the distillery, they are crushed into what is called “meal”, which is a coarse flour. The grains are crushed to get to the starch inside them. Starch is a “polymeric carbohydrate” and before your eyes glaze over and you close the browser thinking “this is getting a little nerdy for me”, give me one second: “Polymeric” just means that the molecule in question (starch) contains multiple smaller molecules that are repeated. In starch, those smaller molecules are glucose (i.e. sugar).
Sugar is exactly what you need to get the fermentation going because this is what the yeast needs to produce alcohol. And that’s why we love those yeast cells so much – because they produce alcohol like there was no tomorrow. They basically piss alcohol and fart CO2 (excuse my French).
There is just one problem: Those repeated glucose molecules inside the starch are held together with a real tough glue called a “glycosidic bond”. Don’t worry about that name – just think of it as glue. Unfortunately, the yeast cells are unable to process the glucose with the glue active.
And this is where malt and malting come into the picture.
Malting simply means that you take some grains, put them into some water, wait until they start sprouting (a.k.a. germinating) – and then dry them again. In other words: Malted barley is just normal barley where a little sprout has come out, as you can see in the picture below:
So why on earth do you want to go through this process? It turns out that grains produce an enzyme called “amylase” when they sprout. Amylase has this amazing property that it destroys the aforementioned glue – effectively converting starch into glucose. And amylase is very effective; By adding just a few percentages of malted grains into the cooking process, it breaks downs the starch in mere hours:
Cool, right?? And once the glucose has been set free, you add the yeast – they do their thing – and we all hold hands and sing kumbaya.
So why barley – and not other grains?
Not many people know this, but you can malt almost all types of grains – including corn. Almost everybody uses barley, though, for three good reasons:
The historic aspect. Depending on who you ask, whiskey production started in either Scotland or Ireland (or maybe another place – who knows), and they have been using barley for the longest time. As you can imagine, the American settlers back in the day (that started distilling) came from those countries. (DISCLAIMER: The are extremely few written records from that time, so exactly who did what with whom – as well as where and when – is unclear).
Production reasons. Barley is easy to handle, easy to dry and produces a great yield of the enzyme amylase.
The flavor profile. Malted barley produces a flavor profile that many people find very agreeable and mating other grains produces a distillate that sort of lack this flavor profile.