Grapes in the northern hemisphere have now been harvested and are well on their way to becoming wine for the vintage of 2018. Reports from Europe indicate good to very good quality from most regions with average yields due to early frost and some loss due to mildew as the harvest approached. Yields were down substantially in California due to ongoing drought but quality is expected to be very good.

Winemakers will have already made their most important decisions regarding the all-important use of oak in finishing most of their wines. With wines from the world’s best known premium wineries there’s no question that aging in oak barrels is essential and expected regardless of cost as it is simply added to the price of each bottle. But for 90+% of wine consumed for daily pleasure the cost of between $1,300 and $1800 per 200 liter oak barrel (about Bt50,000) is a major factor.

Barrels made from wood are part of the history of storing and shipping not only liquids but also dry goods. Walnut, redwood, chestnut and pine in addition to oak are the primary tree species used in barrel production. Following the transition from clay amphorae Greeks stored wine in barrels made from native pine which imparted a heavy dose of resin that acted as a preservative and imparted an unmistakable flavor component. Retsina, as the wine is known, remains popular among selected fans.

In California giant redwood trees growing in close proximity to California’s initial wine region became the wood of choice for fermentation tanks and aging barrels. Quite neutral in terms of flavor compounds the wood was nearly impervious to any form of rot making it appealing for barrels as well as lumber for building construction. Several wineries including Napa Valley’s famed Beaulieu have kept large redwood fermentation vats mostly for historic value.

It’s only in the century or so that barrels made from oak became the preferred container for wine. Oak also showed great resistance to rot with the added benefit of tannins and pigments that moderated harsh components in just-fermented wine. American oak from several Midwestern states is more porous than most European oak and tends to impart a subtle vanilla flavor to wine whereas barrels from French regions including Limousin and Nevers possess greater tannins that add to a wine’s longevity. Considering that an oak tree takes 75 to 100 years to reach the maturity it’s easier to understand the high prices for each barrel and see why careful planning is required in their use.

Modern science allows analysis of specific compounds in each type of oak and its likely effect on acids and sugars in a wine. Winemakers then determine their oak preference and the length of time a particular wine should remain in-barrel. As noted above it’s not a problem for producers of world renowned collector quality wines but is a major consideration for the vast majority of wines enjoyed with daily meals.

Fortunately for more modestly positioned wine lovers creative winemakers can achieve at least some oak benefits for far less money by using oak chips or oak staves during fermentation and aging rather than oak barrels. These oak components are added to large steel fermentation and aging tanks to acquire at least some of the compounds the most expensive wines gain from time in much smaller and much more expensive oak barrels. A fun comparison of the effects of oak on wine is to buy a chardonnay labeled “unwooded” or un-oaked and a bottle of regular chardonnay or a white Burgundy. It becomes very clear that oak contributes subtle flavors to the wine and an even finish even if it lacks the complexity of its hi-so and very high priced brethren. Chokdee!

WRITTEN BY: R. James Mullen