Sweet Wines - all you need to know
What makes a wine sweet? And we are talking about Sweet Dessert wines.
When fermenting grape juice is too sweet, yeasts can’t convert all the sugar into alcohol, leaving behind residual sugar, making the wine sweet. Here are the traditional methods for making sweet dessert wine.
Botrytis : Botrytis cinerea is a fungus. In wet conditions, it destroys grapes, but when the grapes are ripe and the temperature and humidity are just right, it becomes the so-called “noble rot” pulling moisture out of the grape, leaving behind a shriveled berry with ultra concentrated sugars, acids and flavors.
Drying on the Vine : Some grapes dry out on the vine, a process known as passerillage. Sometimes, growers help the process along by twisting grape clusters to cut off sap flow, or by slashing vine branches.
Late Harvest : The juice of late-harvested, ripe grapes are packed with sugar, and can be affected by passerillage or botrytis.
Drying on Racks : Ripe grapes are harvested and then partially dried in the sun or air, causing water loss. In Italy, grapes are dried in well-ventilated lodges and lofts, a process known as apassimento. In Spain, Pedro Ximénez grapes are dried in the sun on esparto-grass mats to make PX wines that taste just like dark raisins.
Freezing : Frozen-solid grapes are harvested and pressed immediately, making it easier to separate the frozen water from the rich, concentrated juice. Of course, modern freezers units can mimic the process.