An overview & glossary of whisky flavours

Depending on the type and distillery, a whisky can have over hundreds of aromas. Not all of these are dominant, there are also many nuances that our senses can hardly or not at all consciously perceive. The aromas are either sourced from the ingredients, created during manufacturing or te result of the complex chemistry of maturation that whisky undergoes before bottled. Then unlike wine, which will continue to mature in the bottle whisky will remain constant in the closed bottle until opened, or accidentally exposed to the elements.

When are the aromas in whisky created?

Whisky is an incredibly rich cocktail of flavours and aromas. A small amount of these flavour comes from the grain itself (malted barley, rye wheat etc). The variety, germination, mash bill etc. all have a role to play. Then kilning of the malted barley can be done is done either with neutral hot air or with peat smoke. This creates what is sometimes called the primary flavour groups which can appear fresh, sweet or malty. If the malt is still peated, smoky, salty or even medicinal notes are imparted at this stage.

Then comes the mashing & fermentation. Then the length of the fermentation, the washback types and temperatures, the yeasts strains used. Many whiskies contain one or more fruit notes. The impression of apple, pear, banana, peach, orange and much more develops to a large extent during fermentation. During these stages, the yeasts convert various molecules into flavour compounds and alcohol. Above all, the fruit esters form here in large numbers and then determine the aroma of the whisky. In addition to the fruit, notes of fresh bread or yoghurt also form as secondary aromas.

Then comes distillation where these flavours are concentrated or cut. The temperatures and speed of distillation (slow or rapid distillation), how the stills are heated (direct firing or indirect heat), the shape of the stills and how many distillations are carried out (double or triple) all impart a unique style and combination of flavours. Oily, sulphurous, somewhat metallic are common descriptions found in tasting notes. These belong to the group of tertiary aromas, which can be created during fermentation, but only become really pronounced and perceptible through distillation.

Other than the master blender, the casks and the climatic conditions have the greatest influence. The whisky absorbs aromas from the barrel during its multi-year maturation, which also involves complex chemical processes. New or used barrels, char level (casks are charred on the inside, creating a layer of charcoal, which on the one hand serves as a built-in activated carbon filter and the wood is also changed by physical-chemical processes, so that it tastes like the raw whisky gives. The size of the barrel also plays a role, the origin of the oak for the barrels and so on. Cask storage imparts new aromas from the wood and the previous contents of the barrel or the surrounding air (sea aromas). Likewise aromas created in the previous steps may be strengthened, becoming more pronounced or these may be reduced, or these may combine or interact with other compounds giving rise to new flavour compounds. When describing these quaternary flavours of whisky, terms like vanilla, clove, coconut, red wine, sherry, roasted nuts, raisins, pepper and so on are common.

Then finally comes the bottling and blending process (single malts are blends, and even single cask whisky may contain more than one run of distillate). As no cask is exactly alike differences in flavour, and colour are normalised to make a consistent signature style. The upshot is that you can find over 400 aromas and flavours in whisky. Some are dominant, others are more subtle taking effort to discover, some you would never expect to have a place in whisky. The below are a small handful of those flavours and flavour groupings.

Flavours and tasting notes Commonly found in whisky

From vanilla to sea salt, from barley to charcoal - hundreds, if not thousands, of exciting aromas can be discovered when tasting whiskies. The below represent a small selection of the most recognisable flavours at a glance.

Pear drops

Flavours that remind you of candy have two points of origins; fermentation and cask maturation. You will experience this especially with young Speyside single malts.

Earth

If a whisky has earthy notes, you can often recognize this in the new make, the raw brandy. This is usually accompanied by a dry mouthfeel that you can still recognize even after years of barrel aging. In addition to smoky whiskies like Lagavulin, you’ll also find this in some Speyside and Highland malts.

Medicinal

Do you know that smell when entering a hospital? That smell of disinfectant? If this occurs with whiskies, it is from the peated barley. Especially with Laphroaig whiskies you smell this clearly.

Coconut

You can recognize coconut aromas in whiskies whose bouquet consists of delicate notes. Coconut notes are reserved and want to be found. In the whiskies, they get through the oak barrel, so they are quaternary aromas. Above all, the molecule Quercus - or whisky lactone is responsible for this aroma.

Tobacco

Does your whisky smell like someone put out a cigar in it? Then you probably have a whisky in your glass that has been in casks for several years. The scent of dried tobacco leaves often develops after several years in the barrel.

Floral notes

If whiskies from Speyside or the Highlands have a flowery bouquet, you can often discover lilacs in them. Single malts get this aroma from the molecule syringaldehyde after years of barrel aging.

Wholemeal Cookie

It is rare for the grain to have an aromatic impact in a whisky. This is ensured by fermentation and barrel aging. These provide flavours that overlay the grain flavour. If you have a Lowland or Speyside whisky with delicate notes, the grain may taste like a whole wheat biscuit. You can already see this in the New Make; So it is one of the few primary aromas.

Banana peels

You will often discover banana aroma in whiskies. Especially since these notes get into the whisky through both fermentation and cask aging. Brown banana peels, on the other hand, are rare. If you want to smell this aroma, then try Tamnavulin whiskies.

Farm yard

A note reminiscent of farm comes mostly from the grain. If this is stored damp, it can modernize and even rot. If this gets into whisky production, this has no health consequences, but leads to distinctive aromas. Some whisky experts also describe this as “cattle breath”.

Orange Blossom Water

With this fragrance, I am glad that it is only discreetly present in whiskies. This gives the bouquet a sophisticated perfume note. A little too much of it and the whisky comes across as monotonous and flat. If you want to smell this aroma, try older whiskies from Speyside Distillery Tormore.

Liquorice

If a whisky is supposed to have liquorice aromas, this deters some connoisseurs. Liquorice isn’t exactly the most popular candy. Too distinctive, too peculiar the taste. In malt whiskies, however, the aroma of liquorice is more reminiscent of liquorice. A milder variant that comes from the wooden barrel or fermentation.

Rubber/tyres

If you have the feeling that a car tire is swimming in your whisky, this is due to the sulphur. This is created during fermentation. Some distilleries try to avoid this aroma through fermentation, distillation and cask aging. Others make it part of their distillery character. For example Braevel, Lagavulin, Macallan or Cragganmore.

Vegetables

If you read tasting notes on malt whiskies, you will discover many fruity aromas. You will find fewer vegetables in it. But this also occurs in numerous whiskies. For example, some Glenlivet whiskies have a subtle eggplant note.

Turmeric

Spice aromas usually come from the wooden barrel, so they are quaternary aromas. They often add sophistication and complexity to a malt. For example turmeric.

Meat

If your whisky shows an aroma that reminds you of meat, then this is once again sulphur greeting you. In addition to rubber, these compounds often also provide a subtle meaty taste in whisky. These notes are often prominent in distilleries using worm tub condensers.

Tar

Tar flavours are primary flavours. They come from the peated malt and provide distillery character. Tar can add complexity to a whisky’s smoky note, but it can also overpower the bouquet. Whisky in which you can discover tar aromas is Ardbeg.

Rhubarb

Rhubarb is one of those flavours worth looking for. They ensure sophistication and individuality in a whisky. Mostly, rhubarb notes are secondary aromas and are therefore created during fermentation. At Tamdhu, this aroma already appears in the New Make.

Felt

If the bouquet of your whisky reminds you of felt, you have a unique piece in the glass. You rarely find felt notes, especially since they often get lost between other notes. The smell of felt or damp felt is somewhat reminiscent of damp grain.

Ginger

Ginger is a flavour that can make or break a whisky. Give it a light sweetness with a hint of lemongrass or tip the malt towards biting perfume. In addition to a small percentage that arises during fermentation, ginger aromas mainly come from the wooden barrel.

Honey

Honey or beeswax is a feature of many Speyside distilleries. Tamdhu and Glenfiddich in particular fly the flag when it comes to honey notes in whisky. These aromas come from storage in virgin oak and ex-bourbon casks.

Lemon peels

Lemons or their peels have an intense fruity-sour aroma. When this occurs in a whisky, it was formed during fermentation.

Chestnut

If you try one or the other Glenfarclas Malt, you have the feeling that it smells like chestnuts. An aroma that is fairly rare and individual.

Fruitcake

Whisky drinkers usually speak of fruitcake when they smell fruit aromas, but cannot clearly identify them. This potpourri has fruit has multiple origins: fermentation and storage.

Espresso

When we speak of quaternary aromas, we mean aromas that develop during barrel aging. If coffee or espresso aromas emerge, the whisky is already a few years old. You will find espresso flavours mainly in Speyside whiskies that have been aged for more than 15 years.

Bitter chocolate

Dark chocolate falls into a category similar to that of espresso. This aroma is created during barrel aging. For this, the whisky should have been in the barrel for many years. Example: Benrinnes

Candied apple

If you smell apples in your whisky, it is difficult to identify its origin. It can be formed by the yeast cells during fermentation, or it is formed during barrel aging. If the apple aroma comes from the barrel, molecules of the lactone group are responsible for this.

Rose water

Similar to orange blossom water, rose water is an exciting aroma in whisky when it appears in nuances. Then the bouquet acquires complexity and individuality. Molecules such as Damascenone are often responsible for this aroma.

Vegetables

In some tasting notes you will find the term “vegetables”. This describes the smell of cooked vegetables. A hodgepodge in which individual grades are not recognizable. These aromas usually arise during fermentation and form a distinctive part of the new make. Search for whiskies from Craigellachie.

Yogurt

Yoghurt flavours are so exciting because they add a rare flavour to whisky: they make it slightly sour. Not excessively. Just enough to get your taste buds going. There is also a freshness that makes whisky an experience. You can find such a yoghurt aroma in some Balvenie Malts.

Pineapple

Pineapple is a classic among secondary aromas. The flavours that the whisky gets from fermentation. You will find pineapple notes in Speyside and Highland whiskies in particular.

Acetone/nail polish remover

Solvent smell that has us screaming “uh, smells like nail polish remover”. This can be produced during fermentation and distillation but these are typically removed by copper contact and so is more commonly from cask maturation.

Identifying flavour groups

For beginners it can be a real challenge to give the whisky taste a name. But of course this is completely normal! Because first the tongue has to get used to the different aromas and taste differences. Nevertheless, you can help yourself with the naming by knowing the most important aroma differences beforehand. You can distinguish 8 different taste differences.

Smoky and peaty aromas

The smoky and peaty flavours are arguably the flavours most likely to be identified in a malt whisky. And they are the ones that contain the “Island Whiskies”. Responsible for this are the aroma groups of the phenols and cresols, which are mainly produced when the peat is burned during the kilning of the malt. If we find this in Speyside whiskies then it may also come from the degradation process of the wood during cask aging. Phenol groups can also form there.

Fruity flavours

What is commonly referred to as fruity in malt whisky is nothing other than the ester aroma group. These arise mainly during the fermentation of the mash, i.e. during the conversion process of sugar into alcohol and CO2. Ester compounds are relatively volatile compounds, which, however, only come into their own in whiskies that are very lightly or not at all peated. A tulip-shaped glass is recommended for such malts, so that the aromas cannot escape so quickly. Most of the associations that whisky lovers use to describe them more specifically are: Fresh fruits such as orange, lemon, kiwi, apple or dried fruits such as plums, figs or fruits.

Floral flavours

The fruity and floral (flowery) aromas belong in one category. The floral aromas are also often confused with the fruity aromas because their taste impression is similar. Since the floral aromas are also very volatile, they are quickly overpowered by the heavy, oily aromas like peat and grain.

Vanilla

The vanilla aroma is created solely by fermentation. The vanilla pod (an orchid fruit) also produces the vanilla flavour through fermentation. In malt whisky, the vanilla flavour is created either during fermentation or during cask aging. Mainly, however, the barrel maturity is responsible for the vanilla aroma. During the aging process, the flavouring substance vanillin is released from the barrel wood and goes into the malt. Vanillin is a very pleasant fragrance that one likes to have in whisky. However, it is too expensive to add it artificially.

Caramel

The sweet caramel aroma comes from the lignin, a wood component that is dissolved during the barrel aging. The degradation of lignin is a decomposition process, namely the transformation of the wood into usable sugar (wood saccharification). However, you only get to the cellulose (cellulose is the most common polysaccharide –> polysaccharides are multiple sugars) when the lignin from the wood is broken down, for example by chemical, hydrothermal and enzymatic processes.

Nutty flavours

come about either during barrel aging or during fermentation. These flavours are aldehyde compounds and flavonoids. Flavonoids are water-soluble plant pigments and belong to the polyphenols. Natural polyphenols (hydroxyl groups) are found in plants as bioactive substances such as colorants, flavours and tannins.

Grain flavours (cereals)

The cereal aromas are probably grassy aldehyde compounds (these aroma substances arise in so-called catalysis processes of the linoleic and linolenic acids of various plants) from the remains of the after-run, which is carried over into the next distillation cycle. A number of aldehydes are found in the metabolism of individual cells. Perceived associations would be wet flour, candy corn, pale ale, malt, or roast.

Grassy, leafy aromas Aldehydes

Aldehydes (dehydrated primary or oxidized alcohol). It is believed that these aldehydes are formed during cask aging. In many biochemical processes in the cell, e.g. B. glycolysis, organic compounds are snatched hydrogen atoms by certain coenzymes (NAD, NADP, FAD). Many of these aldehydes have a pleasant fruity or floral odor.

Sulphurous aromas

Sulphur flavours are present at virtually every stage of whisky making. They are relatively volatile compounds.

Sulphur compounds from germination

The proportion of sulphur compounds can already be measured during germination. In general, DMS (dimethyl sulphide) is formed during the kilning process, which produces vegetable and cabbage-like aromas. Flavours of sweetcorn and cooked vegetables are then identified in the malt.

Sulphur compounds from brewing and fermentation

Both during the cooking (brewing) of the grain-water mash and during the main fermentation or fermentation, reactions occur that form sulphurous aromas. This is the biosynthesis of sulphur-containing amino acids and the reduction of sulphate salts in the wort (word). A series of biosynthesis of various amino acids takes place during beer production. But the most unpopular are of course the sulphur-containing compounds, as they have the unpleasant aromatic side effects. Extremely undesirable is the hydrogen sulphide H2S, which is a rather foul-smelling, highly toxic gas. Although the H_2S is partly derived with the CO2 (carbonic acid) produced during the fermentation, some of the sulphur compounds always remain in the wash (wort). This arises in the reduction of sulphates to sulphides. However, it must also be said that the very bad smells during fermentation can arise as a result of incorrect fermentation by foreign yeasts.

Sulphur compounds from distillation

The copper from which the stills are made has a very favourable influence on the distillate in order to remove sulphur compounds. It is also interesting that the ratio of copper surface to still volume plays a very important role in removing sulphur compounds. This is usually not big enough. Sulphur compounds produced by the yeast are mostly of a volatile nature and are reduced and removed in the wash still. The wash still is the much larger still. The copper in the still is a catalyst by which the sulphur compounds react to form insolubles which are then removed by the alcohol vapor. The pyrolysis reactions that take place during the distillation of the mash also yield a significant proportion of DMDS and DMTS, which increases with the distillation time and the temperature. You should know that there are sulphur compounds such as methyl thioacetate that come directly from the mash and therefore cannot be influenced, such as DMDS, which can be controlled by the distillation. Oak wood and air are essential for removing sulphur compounds from the distillate.

Sulphur compounds from barrel aging

The resulting DMDS during distillation falls over time with long barrel storage. For whiskies that have been stored for a long time, the DMDS percentage drops considerably. The charring of the barrels before filling also has a positive effect on the distillate, as it acts like an activated carbon filter and filters out sulphur compounds.

Acid

Acids are mainly formed during very long barrel storage. These are often flavours that are identified as sour fruit or fruitcake.

Musty, bad flavours

Whiskies with aromas reminiscent of mold cellars and mothballs are usually discarded immediately, as this indicates that the malt has developed incorrectly during cask aging. The reasons for this are probably, for example, bad barrels (mouldy barrels), bad storage, etc.

Young wood flavours

Very aromatic aromas of freshly cut wood and resin suggest new barrels.

Old wood flavours

The astringent tannins that form in older woods and are transferred to the malt during storage are typical of a cask occupancy in older casks. These flavours are also known in older red wines that have matured in barrels for a long time.