Understanding alternative wood and its reaction to wine

Wood alternatives have been a topic of debate as well as of interest for some time now, writes Leilani Sell. Alternatives for wine maturation has become a popular choice for wineries/winemakers purely due to its cost effectiveness.

With the cost of a new wine barrel, you would need to place barrel-wooded wine into a price point of over R150 a bottle, but with wine at a price point of R60 and less, the use of alternative wood for wine maturation makes more financial sense. Fortunately consumer demands over the last few years have seen a trend for more lightly wooded wines, wines that are easily accessible on the palate at a younger age, and of course, wines that fit the budget in these economic times.

Why is the use of wood so important from a marketing aspect? Wooded wine is seen as better product; you are able to age the wine, you are selling a premium product and can get a better price for the wine. From a winemakers point, wood influences flavour, mouthfeel, astringency, longevity, the structure of the wine, stabilizes the colour of wine, and the chemical processes that happen in wine with the addition of wood are very important to a winemaker.

Once the choice has been made to use alternative wood products, it is important to understand how to use them, and to understand why you use wood for wine maturation, because it is a very different game to using barrels. The biggest advantage of a barrel is of course the consistent, natural micro oxygenation that occurs over a long period of time in the barrel, and it is difficult to recreate this in a tank; this is tricky, but vital to the success of using wood alternatives successfully.

There are various times of application for wood alternatives; on crush, during fermentation and on or after MLF (malolactic fermentation), and lastly in older barrels.

Rather than looking at when we use alternatives, let’s first look at why we use wood for wine maturation.

Wood effects the colour, flavour, tannin profile, astringency and texture of wine. Let’s have a look at phenolic compounds in wine. These are the chemical compounds that effect colour, taste and mouthfeel in wine, of which Flavonoid, Flavonols, anthocyanins, phenolic acids and flavonois are the most important.

The study of phenolics is one of the most complex sciences in the world, and is still on-going. Fine wines are a result of total phenolic management, from the vineyard to the bottle, but a lot of manipulation can be done with wood to improve and help the polyphenols in young wine.

Polyphenols occur naturally in grapes and are distributed in different quantities throughout the berry, and will differ between various grape varieties. For example, the anthoyanins (responsible for the red and purple colours in the grapes) in pinot noir has 100mg/l to a cabernet sauvignon that has 1 500mg/l!

Anthocyanins are influenced by different reactions during winemaking, which in turn effect their stability. Anthocyanns will diminish with age, the addition of sulphur (sulphur bleaching), oxidation and pH levels will effect this. The addition of wood to wine helps with polymerization to stabilize the anthocyanins. Colour stabilization is directly related to wine quality, so the application of enological techniques to improve this factor is of major interest. Any reaction that prevents anthocyanin bleaching, preventing its oxidation or helping its polymerization will maintain the desirable colour of the wine.

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