What exactly....

[Original Mac]

...does oak bring to the party? When I started my first Beaverdale wine I chucked in the oak which stayed there until fermentation was finished. This was pre winesathome education you understand. The wine was perfectly drinkable but I did not care for the oak profile which I found overpowered the grape (Cab Sab if I recall correctly). It only lasted a couple of months so no long term study happened, I decided I did not like oak in my wine and never used it since. Until I used half an oak packet in an elderberry, same result, not impressed and I ended up blending to reduce the oakiness. Except for two bottles which were put away (forgotten about actually) for almost two years. Visit from my brother in law prompted a bottle opening and if I believed in a superior deity I would have called upon him/her/it. Talk about the food of the gods, it was superb with hardly a trace of the oak. It was as smooth as silk and even I could detect subtle flavours (even vanilla!) Certainly the best wine I have ever made. So now I am confused. Does the oak (like tannin) need time to mellow? What exactly does it bring?

[NorthernWiner]

Does the oak (like tannin) need time to mellow? What exactly does it bring?

Yes, oak will mellow and integrate over time. As for what it brings to the party, it all depends on how you use it. Just chucking a handful of chips into your wine will give you some oak flavor and tannin (yes, oak contains tannin), but little else. On the other hand, aging wine in a barrel offers a few benefits. In addition to imparting oak flavor, it mellows out the wine by allowing it to come in contact with a very tiny amount of air through a process called micro-oxygenation (often abbreviated as "microx"). And as the wine evaporates, it also concentrates the flavor. Over a 12-month period, you can lose as much as 25 liters through evaporation in a full-size barrel.

Note that different types of oak have different flavors. French oak adds caramel and coffee character, while American oak contributes a good does of vanilla and toasted coconut.