Noun
pyrazine (plural pyrazines)
(organic chemistry) A diazine in which the two nitrogen atoms are in the para- positions; many of its derivatives are pharmaceuticals.
At the time of veraison, when the grapes first start to fully ripen, there is the equivalent pyrazine level of 30 ng/l. Source: Internet
In cooler climates, it is difficult to get Cabernet Sauvignon grapes to ripen fully to the point where pyrazine is not detected. Source: Internet
To the human palate this compound is detectable in wines with pyrazine levels as low as 2 nanograms (ng) per liter. Source: Internet