lactones are a group of phenols derived from oak that create many aromas, flavors, and textures in barrel-aged spirits. These include complex milky or coconut notes, vanilla, balsam, wood, pastries, earthiness, apricot, peach, leather, spices, green walnuts, and fresh herbs.
As much as phenolic influences can be altered during barrel aging by the condition of the wood and its heating, burning, and such, differing woods (including species of oak) offer differing phenolic and other compounds. American oak is described as containing two or three times more coconut than European oaks (as well as more cocoa and caramel), but some of this (especially the cocoa and caramel) is due to differences in barrel production methods.
See also phenol.
“Whiskey Lactone.” American Chemical Society. https://www.acs.org/content/acs/en/molecule-of-the-week/archive/w/whiskey-lactone.html (accessed March 27, 2021).
By: Doug Frost