Everything about PPM and smoke in whiskey. We explain what phenols are, why a higher PPM value does not necessarily guarantee a smokier whiskey and why peat (German for: Peat) is essential in the production of smoky whiskeys.
What does PPM mean? - (Phenol) Parts Per Million
PPM stands for Parts Per Million and is a term widely used in the whiskey industry. PPM is the measure used to determine the phenolic content of malted barley . The measurement is made after kilning (the process of drying the barley with hot air) and before it is used in the subsequent whiskey production process.What are phenols? - The chemical compounds that provide a smoky aroma
In whiskey, phenols provide the smoky aromas and flavors that make the peat lover's heart beat faster.
Since this is not intended to be a chemistry article, we limit ourselves to the minimum required for the whiskey enthusiast. Phenols are a class of organic chemical compounds that contain a hydroxyl group (-OH) attached to a carbon atom in a benzene ring . To ask?
And if you want to shine at the regulars' table the next time, remember that it is mainly 4-ethylphenol, 4-ethylguaiacol and guaiacol that are responsible for the smoke notes that we recognize.
End of the chemistry course.
How does the smoke get into the whisky? - Keyword Peat
We have already discussed that phenols are responsible for the smoky character, but how are phenols formed and how exactly do these phenols get into the whiskey?
Phenols are formed when peat is burned. Because peat is an ideal fuel, it has been used to dry barley during whiskey making for centuries.
It is best to imagine a barn with two floors. On the upper floor, the still wet, malted barley is spread out on the floor (malting floor, German for: Mälzboden). On the floor below, a fire is lit in a still called a 'kiln' and fueled by the addition of peat.
The burning of the peat produces the smoky phenols, which rise with the hot air to the second floor, where they dry the barley. During this drying process, which is known professionally as "kiln drying", the small phenol particles are deposited in and on the barley and, after drying is complete, are ground together with the barley and processed further. And so the phenols find their way into the whiskey and the longer the malt is exposed to the peat fire, the higher the phenolic content becomes.
Digression peat:
Peat is the top organic layer of a soil, composed of partially decomposed organic matter, mostly derived from plant matter, accumulated under conditions such as waterlogging, lack of oxygen, high acidity and nutrient deficiency. In Scotland, especially on Islay, the soil is very peaty and can therefore be easily cut with a spade and removed from the earth in long pieces.
The picture shows a typical peat landscape and at the same time the pieces of peat cut out of the earth, which are later used for burning in the oven.
The higher the PPM number, the smokier the whiskey. Is that correct? - Not necessarily
Especially in the Scottish whiskey region of Islay , people like to boast about the highest possible PPM numbers on the bottle labels and thus suggest an extremely smoky whiskey to the customer. Above all, Octomore and Ardbeg have developed into real cult brands in the field of smoky whiskies. There is nothing wrong with that, because in fact the whiskeys from the island of Islay are considered to be the smokiest that the Scottish and global whiskey market has to offer.
However, the PPM value, i.e. the number of phenol particles per million parts, does not really indicate how smoky the whiskey is that ends up in the bottle. Why is that? Very easily. It is at the point in time when the phenol content is measured during the whiskey making process.
When is the phenol content in whiskey measured? - At the very beginning of whiskey production
The PPM measurement is not determined during or just before bottling of the whiskey, as might well be expected , but many years earlier, at the very beginning of the manufacturing process, after the malted barley has dried. That means the PPM value is measured before the whiskey is filled into casks and even before the actual distillation process.
This in turn means that a whole range of influences can influence the smoke content between the PPM measurement and the final whiskey in the bottle. How many and which phenols end up in the finished whiskey depends on the following factors, among others:
- How well and completely are the phenols extracted from the malt grist?
- What proportion of the phenols evaporate during the distillation?
- To what extent are the substances degraded over the course of several years of storage?
- What is the percentage absorbed by the oak wood in the barrels?
From a technical point of view, the PPM value could of course also be determined without any problems after distillation or even during bottling. Why is this not done in practice? The marketing of the whiskey industry works according to the principle "more is more" and since the PPM value decreases with each step of the whiskey production, they prefer to convince the customer of the smokiness of the whiskey with the largest possible number. Clever but maybe a little misleading, right?
In order to simplify your search for the right whiskey and to make sure that you keep track of the smoke, we have divided our whiskeys into the following three smoke categories in the online shop .
2. LIGHT TO MEDIUM SMOKY WHISKEY
Peated | Smoky - The correct whiskey vocabulary
For those who are still unsure about the choice of words to describe smoky whiskeys, here are a few examples, both in English and in German.
“The whiskey is heavily peated and has strong smoke flavors”
”The whiskey is extremely smoky”
“I can clearly smell the peat in this whiskey”
“The smoky notes in this whiskey are unmistakable”
”Wow, the smokiness in this whiskey is unbelievable”
“Smells like BBQ. Must be a peated whisky”
In the end, all of these phrases describe the same thing and whether you call a whiskey smoky (“smoky” in English) or peaty (“peated” in English) really makes no difference to the tasting. As long as it is understandable for the other person and for yourself, don't worry about which words you use.
Ok, there is one more highlight to describe heavily smoky whiskeys: “Disgusting! It smells like a wet ashtray and tastes the same.” -> By the way, this sentence comes from myself when I had my first Ardbeg in the glass.
Smoky whiskeys are certainly not for everyone and you definitely shouldn't force yourself to like smoky whiskeys. But don't be afraid to pour a smoky whiskey into the glass every few months, because usually the nose and palate have to get used to this kind of smell and taste. Caution: once you get a taste for it, it's hard to let go!!
What are the smokiest whiskeys and what are their PPM levels?
As you might expect, Islay's distilleries dominate the list of the best known smoky/peated whiskeys. Not every distillery takes the trouble to determine the phenol content of their whiskeys and even on Islay the PPM specification is far from found on the bottles of all distilleries.
Here is a selection of distilleries with an indication of the average PPM values. Certain special edition distilleries may also have significantly higher phenol levels. With a click on the brand you will be forwarded directly to the corresponding distillery in our shop.
| brand | PPM |
|---|---|
| Ardbeg | 50ppm |
| Bowmore | 25ppm |
| Caol Ila | 30ppm |
| Kilchoman | 20ppm to 50ppm |
| Lagavulin | 30ppm |
| Laphroaig | 40ppm |
| Octomore | up to 309ppm |
| Port-Charlotte | 40ppm |
Conclusion
By specifying the PPM value on the bottle label, the whiskey industry has managed to convince customers of the smokiness of the whiskey in a simple way. It should also be clear after reading this article that PPM values should at best be used as a guideline for the peatiness / smokiness of a whiskey. For friends of smoky whiskey, however, only the following is important in the end. Is the smell convincing on the nose, is the whiskey fun on the palate and do you like the finish? If so, it doesn't matter whether the label says 2, 20 or 200ppm. In this sense: Sláinte!
Finally, a small selection of heavily smoky whiskeys from our shop
1. ARDBEG TEN - THE ISLAY CLASSIC
2. OCTOMORE 12.2 - THE REAL PPM MONSTER
3. KILCHOMAN SANAIG - THE INTERESTING ALTERNATIVE
