White wine fermentation often takes place in stainless steel tanks with lower heat levels that are closely monitored and the oxygen levels strictly guarded (to prevent rapid oxidation). Chardonnay is one exception, some winemakers prefer to hold the Chardonnay juice in sealed oak barrels for fermentation to influence flavor development.
If during the fermentation process the grapes were not quite ripe enough, sugar may be added to the must to increase alcohol levels in the final product, this addition is referred to as "enrichment". Likewise, acid can also be added to the must if the acidity is low, this is understandably referred to as "acidification." Also with white wine fermentation an additional step referred to as "stirring the lees" is added. This step involves mixing up the residual yeast that is left post fermentation to yield more flavors.
