Which chemicals are responsible? For the distinctly green leafy aroma, cis-3-hexenol is the prime culprit, but I have additionally seen 2-isobutylthiazole listed as the signature chemical behind that smell.

Which wines have it? Tomato leaf is a Sauvignon Blanc sort of descriptor. It’s pungent and quite green, and it is often used to

describe Sauvignons from the cool Awatare Valley in Marlborough. It’s a very appealing smell, although I’m not certain I’d want too much of it in my wine.

As with many of these descriptors, after a while it becomes a bit of a cipher word. As we taste, we decide what sort of wine we are tasting, and soon after trot out the usual terms that we associate with that wine. To smell and taste what’s actually there requires quite a bit of concentration and planned effort.