ppm (phenol parts per million) is usually a reference to a "pre-distillation measurement" though, not the resultant distillate or the final aged product. Different run cut points (head/tails) heavily impact the amount of peat flavors that make it into the final distillate, as well as age (barrel time), cask activity, and.. probably barrel char too?
So while there is of course a rough correlation with ppm to final "peatiness", some scotches with slightly higher initial ppm may not end up tasting quite as "peaty" as some with slightly lower initial ppm may.
It does seem like PPM is being used "as marketing" in a few places these days though, which is probably to your point, and possibly a sign of things to come. :/
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A more common thing I see/hear is people bragging about scotch age and price. Older is not always better! Too old, and you can certainly lose some delightful peat characteristics present in younger ages, or get too much cask influence.
So while there is of course a rough correlation with ppm to final "peatiness", some scotches with slightly higher initial ppm may not end up tasting quite as "peaty" as some with slightly lower initial ppm may.
It does seem like PPM is being used "as marketing" in a few places these days though, which is probably to your point, and possibly a sign of things to come. :/
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A more common thing I see/hear is people bragging about scotch age and price. Older is not always better! Too old, and you can certainly lose some delightful peat characteristics present in younger ages, or get too much cask influence.