Wine Spirit for Port
There is still some confusion on people’s heads about Port winemaking. The basic details are not difficult, but when we talk about the spirit we use to fortify the must, sometimes explanations complicate what is easy simple. So very often I receive emails from people asking what wine spirit we use and how strong it is. I hope I can help you better understand this particular point about Port.
What makes Port Port when compared with the regular wine is the spirit we add during the fermentation. The first half of the fermentation, this is, the convertion of the sugar of the grape into alcohol, is similar to wine. What really changes is when half of the sugar is transformed into alcohol. At this point, for each four liters of must we add around one liter of 77% abv spirit, made from distilled wine. When this is happening, we still have around 7% of potential alcohol unfermented. And unfermented it will stay as the yeast that is eating the sugar of the must and transforming it into alcohol dies. Once the spirit is combined, the alcohol level rises to around 19% and at this point yeast can’t survive. Quick note to remind you that when we talk about sugar, we are referring to the natural sugar of the grape, known as fructose. Contritely to other wine regions with cooler temperatures and consequently lower sugar levels, in the Douro no sugar is added to the must as our grapes have plenty of sweetness and ripeness. Later, during aging in pipes or tanks, some alcohol adjustments may be necessary, but most of the time these corrections won’t be higher than 1 percentage point.
Currently, some research is being conducted to check whether using stronger wine spirit to fortify the must (+90% instead of 77%) would have similar effects on Port quality. To reach spirit with 77% abv the starting level is near by 100% and then water is added to dilute the spirit. So, is this water really necessary to dilute the spirit?
Let me know your questions and comments.
Happy New Year!