Wood Chips and Wine Treatment; the Nature of Aqueous alcohol extracts

Abstract

The extraction of material from oak wood meal reached nearly the same level in 1 day as in 16 days. The extraction from chips was a little slower and from chips previously extracted with water slower yet. Although the amount of solids extracted by the various alcohol concentrations varied from 2.9 to 5.9 per cent of the dry weight of the untreated wood, the composition of the extracted substance was nearly constant in the wine range of alcohol concentrations (10-20 per cent) averaging 0.433 g tannin calculated as gallic acid, and 0.153 g of acid calculated as tartaric per g of solid extracted. The pH was about 3.9. The absorbance af 275 mµ was 0.26 and af 225 mµ was 0.72 of that at 203 mµ. Data on relative color at 440 mµ are given.

There are some qualitative differences in composition of the substances extracted from the wood under different conditions. Preliminary sensory tests showed that detecfalole flavor changes may be produced by addition of wood extract to wine without changing the usual analyses appreciably.