It was on a cold winter’s evening, when me and some mates sat down by a nice roaring fire and I first tasted a peaty whisky that one of the guys brought along. It was a 10-year old Talisker Single Malt. I was instantly hooked by the smokey taste of the Talisker, something I’ve never tasted in a whisky. My friend told me that this whisky is a peaty whisky. Peaty?
In this new blog post, I will explain how the distilleries give their whiskies this extraordinary flavor.
The island of Islay
The island of Islay (pronounced as ‘Eye-lah’), situated on the Scottish west coast, is renowned for its heavy, smokey whiskies. This island is covered by many marshlands and peat bogs. Iodine, tar, seaweed and sea salt gives Islay’s peat its distinctive smell due to decomposed marine vegetation. When being burnt to kiln barley during the malting process, the Islay peat smoke gives the barley a different flavor when compared with peat cut from the Scottish mainland.
Peat and malting barley
The grain used for single malt whiskies is exclusively barley, Hordeum vulgare. New barley varieties are continuously introduced, with the main focus on increasing the amount of alcohol they yield. Turning the raw, hard barley-seed into whisky requires it to be malted to access the starch within the grain and convert it into sugar. Malting the barley takes 4 to 12 weeks, depending on the humidity, the temperature and the airflow during the process. The grains are first steeped in water for 2 or 3 days, then spread out in a warm, damp environment to germinate. Most of the Islay-distelleries, who malt their own barley, still use the traditional malting floor to sprout the barley. Once the seeds begin to sprout, germination is being halted by drying the barley, or ‘green malt‘ using a kiln to reduce the water content from 44% to 5%. And that is where peat comes in!
The peat, which left to dry for about 2 weeks after being cut from the bog, is burnt in a kiln underneath the malting floor to arrest the germination. The smoke seeps through thousands of tiny holes in the malting floor and imparts its distinctive peaty flavor to the grain. With a risk of stating the obvious: the longer the malt is exposed to the peat smoke, the peatier the whisky will be. After 16-18 ours the ‘break‘ is reached. At this stage, the barley no longer absorbs the reek as a result of the decreasing moitsture content in the grain itself. After malting the barley, the following stages in creating whisky takes place: mashing, fermenting, distilling and maturing.
The ‘peatiness’, or ‘peat reek’, of malted barley is measured in Phenolic Parts per Million (PPM). Traditionally distilleries on the Scottish west coast use more peat reek than those in Speyside and on the east coast. In short, the higher the PPM levels, the peatier the whisky will be to taste.
Very heavily peated: 50 ppm – 170 PPM (Ardbeg at 55 PPM, Bruichladdich Octomore at 169 PPM)
Heavily peated: 30 ppm – 50 PPM (Laphroaig at 40-43 PPM)
Moderately high: 20 ppm – 30 ppm (Talisker at 25-30 ppm)
Medium peated: 15 ppm – 20 ppm (Highland Park at 20 ppm)
Moderately low: 5 ppm – 15 ppm (Ardmore at 10-15 ppm)
Lightly peated: 1 – 5 ppm (Bunnahabhain at 3-4 ppm)
Unpeated: none, but even unpeated malt can have 0.6 to 0.8 ppm (Bunnahabhain at 1-2 ppm)
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