In one sentence: Oak can be a fermentation vessel, a maturation vessel or both. Its influence depends on species, origin, toast, age, size and time in contact with the wine.
UsesFermentation, maturation
VariablesAge, size, toast
Main effectFlavour, texture, oxygen
What does oak do?
It can introduce flavour and aroma, allow slow oxygen exposure and influence texture and integration.
French oak or American oak?
They can differ in grain, extraction and flavour profile, but cooperage choices are more nuanced than country alone.
Does all oak taste obvious?
No. Older barrels, larger formats and shorter maturation can give structural or oxidative effects without strong overt oak flavour.
Why can oak overwhelm Pinot Noir?
Pinot Noir can be delicate. Wine Australia notes its affinity with new oak while warning that the fruit profile can be overwhelmed, encouraging careful percentages and larger formats.