How do winemaking processes influence the levels of oak aroma compounds actually present in wine?
The choice of barrels, the proportion of new oak, and the length of wine oak contact are the most obvious factors influencing wine wood aroma. Microbial activity also has an influence. When fermentation is carried out in barrel, aldehydes such as vanillin, furfural, and 5-methylfurfural may be transformed by yeast into non-aromatic alcohols. Absorption of aroma compounds by yeast cells and macromolecules is also possible.
