LEARNING ABOUT PEAT AND PHENOLS
Peat, also known as turf,
is an accumulation of partially decayed vegetation or organic matter. It is
unique to natural areas called peatlands, bogs, mires, moors, or muskegs.
Peatlands, particularly bogs, are the primary source of peat, although less-common
wetlands including fens, pocosins, and peat swamp forests also deposit peat.
Organic matter accumulates over thousands of years to create peat deposits.
Under pressure, water is forced out of peat, which is soft and easily
compressed, and once dry can be used as fuel. In many countries, including
Ireland and Scotland, peat has traditionally been used for cooking and domestic
heating, and peat is stacked to dry in rural areas. It is harvested on an
industrial scale. But it is the use of peat in the Scottish whisky industry
that helps to produce a drink that has a unique flavour within the world of
spirits and why different distilleries have different characteristics in their
whiskies.
The peat is cut by hand
using specialised tools and the resulting 'sod' is then left to dry in the open
air for approximately two-three weeks. After this time, the peat is collected
and then taken to the distillery. Most of the time the peat used is local to
the distillery or cut from property owned by the distillery. Peat is so tightly
compacted and dense that it burns for a long time and with consistent heat and
acrid smoke. This is also why it is still used as a domestic fuel in some areas
of Scotland, especially the islands.
Some Scotch whisky
distilleries, such as those on Islay, use peat fires to dry malted barley. The
drying process takes about 30 hours. This gives the whiskies a distinctive
smoky flavour, called "peatiness". Peat smoke produces contains
chemicals called phenols which are
absorbed by the malted barley during the drying process in a kiln. The level of
phenols are controlled by the length of time that the barley is exposed to the
smoke, the amount of smoke produced and the type of peat used. The smoke that
has been absorbed is then carried through the entire whisky making process and
right into your glass.
Scotch Ales can also use
peat roasted malt, imparting a similar smoked flavour.
Peat can be a very
divisive flavour component in the world of whisky. It is most commonly found in
the single malt scotch category, although it is also present in whisky from
Japan, India, Ireland, and even the Pacific Northwest. As malted barley is
heated to dry it out and stop the germination process, peat is burned to infuse
the grain with smoke and flavour it. As stated, the peatiness of the whisky
depends on how long it has been exposed to the smoke, and measured in PPM
(phenol parts per million). A measurement of one ppm means that there is one
milligram of phenol per kilogram of malt. The higher the PPM, the smokier the
whisky. Generally speaking, concentrations of less than five ppm are virtually
undetectable for most drinkers.
There is a wide range of
smoky whisky to enjoy, from light and crisp to medicinal and heavy to one of
the highest PPMs distilled in recent history. If you think you don’t like smoky
whisky, perhaps you just haven’t tried the right one yet. A peaty dram is best
enjoyed in the winter, as the cold temperatures, limited sunlight and dreary
skies lend themselves to these flavours, especially when warming up by an
equally smoky fire.
These days, Malting Houses
deliver specifically ordered malting to a distillery, meeting the barley and
malting specifications of the distiller. At a malting’s laboratory, samples of
malt are analysed for phenols, moisture, nitrogen content, and predicted spirit
yield. Having malted barley peated to a higher ppm can contribute to a
peatier-tasting whisky, but the ppm of the raw material is not a measurement of
peat or smoke flavour in the bottle. Using the malt’s phenol ppm to predict
final flavour is neither practical nor wise. The ppm of the malt remains independent
of the processes involved in making whisky; the milling, mashing, fermentation,
distillation cuts and maturation, each of which can affect the degree of smoke
and peat flavours that reach the bottle. Leaving peat monsters like Ardbeg
Supernova (100 ppm), and Bruichladdich’s Octomore 6.3 (258 ppm) / 8.3 (309 ppm)
aside, recent labels on whiskies from Ailsa Bay and AnCnoc show the ppm
measured in the final liquid.
Here are some examples of
PPM values of some well known distilleries, as stated by WhiskyFor Everyone and
others:
Bunnahabhain (1–2)
Bruichladdich
(3–4)
Springbank
(7–8)
Benromach (8)
Hakushu 12
YO, Japan (8)
Ardmore
(10–15)
Tomatin Cù
Bòcan(15)
Highland Park
(20)
Bowmore
(20–25)
Talisker
(25–30)
Caol Ila
(30–35)
Paul John
Peated Cask Strength, India (30-35)
Jura Prophecy
(35)
Ledaig (35)
Lagavulin
(35–40)
Port
Charlotte (40)
Laphroaig
(40–43)
Ardbeg
(55-65)
Longrow (55)
Benromach
Peat Smoke (67)
Hi I'm a new into whisky and I'm quite intrigued by the so called ppm measurement and by that I was wondering how was octomore 8.3 reached to 301 ppm and how would they do that?
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