Linalool is a so-called tertiary alcohol of myrcene—a classification based on the molecule’s carbon arrangement. It is a potent odorant in hops and beer. As an alcohol, it is considered part of the oxygenated fraction of hop oils and consequently is more soluble in wort and beer than its counterpart myrcene. Linalool has a distinctive floral aroma reminiscent of rose as well as lavender and/or bergamot. It also has citrusy and woody notes. Linalool is found at low levels of perhaps 10 to 100 ppm in hop oils, but it has an extremely low odor threshold for humans—down to 2 ppb in most lagers, for instance. This means it can be a very noticeable component in a beer’s aroma. It is commonly present in regularly hopped beers at a range of 1 to 30 ppb, but it may reach as much as 100 ppb or more in dry-hopped beers. Agronomically, linalool concentration in hop oil can vary significantly within the same variety, even in the same hop yard, but from different years—sometimes by as much as a factor of 2. Some researchers believe that linalool serves as a marker for hop aroma in beer, especially when German lagers are flavored with German aroma hops, simply because higher levels of linalool in beer tend to correlate with hoppier aromas in lagers. Nevertheless, linalool is only one of many hop aroma components derived from the many different essential oils in hops.
