Last week we touched on soil considerations for new vineyards, thank you everyone Spencer Connell and Shelley Sharpe for your responses!
This week: Sweets
Name and describe various winemaking methods for achieving wines with residual sugar.
I start with one I'm currently studying: Mutage.
Mutage is a process to create vin doux naturel (sweet fortified wine) from all three colors of wine in which pure grape spirits are added during the fermentation process in a proportion of 5 to 10% to stop fermentation. This allows the wines to retain some natural grape sugar.
Riversaltes, in Roussillon, is the birthplace of vin doux naturel and the home of Arnaud de Villeneuve, a physician who introduced the process of mutage for medicinal purposes in the 13th century.
Residual sugar can also be achieved if the grapes have a high level of natural sugar. During fermentation, the yeasts may die from "alcohol poisoning" prior to converting all of the sugar (and thus leaving some behind) due to the high level of alcohol (around 16%) from the sugar that was converted.
Grapes can have high levels of natural sugar by/through:
1. being picked when sugar content is high (left on the vine longer to achieve extra ripeness);
2. laying them out on mats to dry out, which concentrates the sugars (think Amarone for example of part 1 and 2);
3. letting the grapes freeze on the vine such that water can be separated from sugar juice (icewine); and
4. Botrytis (noble rot) that consumes some of the water in the grape's pulp thereby concentrating the sugar.