Arbutus Unedo L. Spirit: Does The Water Addition Before Fermentation Matters?

The strawberry tree (Arbutus unedo L.) is a shrub that plays an important role in the territorial sustainability due to the production of a spirit known as "aguardente de medronho" made by distilling its fermented fruits.This work intends to study the influence of adding water to arbutus fruits before the alcoholic fermentation, on the chemical composition of the obtained distillates.A set of fruits from the same orchard was used to fill fermentation containers in presence and absence of water addition. After the fermentation the distillation was performed in a copper small-sized alembic (boiler-15 L capacity). In the distillates, pH, volatile acidity, titratable acidity and volatile composition were determined. At the same time, the heart fractions, obtained in an industrial copper column alembic (boiler, column-200 L capacity), proceeding from the same fermented containers were evaluated.The statistical analysis of the results shows a significant effect of the water addition on the composition of the distillates. The distillates resulting from fruits that fermented with water, present higher pH, lower acidity, lower acetaldehyde amounts and higher amounts in some fusel alcohols than the distillates resulting from fruits that fermented without water. This effect is not so pronounced in the distillates obtained in industrial conditions. In this case, the addition of water significantly influenced the amounts of titratable acidity, acetaldehyde and ethyl acetate in the first harvesting and the pH and isobutanol amounts in the second harvesting.