Daniel Veit, inderpal singh and Morgan LaCroix weighing in on the magical aspects of Valtellina Superiore DOCG last week. Riding a unicorn through the mountains with a healthy flagon of Chiavennasca sounds pretty awesome to me, just saying.
This week: Fortification. When and how is this performed for Port, Madeira and Sherry?
For Port, spirits are added during fermentation, arresting fermentation and preserving sugar in the final product.
In Sherry, the spirits are added post fermentation, and the level helps to determine what style of Sherry is produced.
Above 17% abv, flor can not reproduce, leaving the wine open to oxidisation, producing Oloroso Sherry. Below, and the wine can be protected by the layer of flor, preventing oxidisation, but instead aging biologically, producing Fino and Manzanilla Sherry.
In Palo Cortado Sherry, the wines are generally started under flor, but then fortified above 17% abv, killing the flor, and finishing the aging process in an oxidative environment.
I don't know the technical details for Madeira, so I'd rather hear someone else comment on that.
Madeira fortification, as with Port, is the byproduct of making the wine stable to transport. The wines were being carried on vessels bound for long distances (Africa/Asia/North America), and did not last these voyages. Initially small amounts of alcohol from sugar cane were added to stablize, eventually brandy (grape spirit) was/is used. When the fortification is added depends on the verietal being used and style being made, earlier in the process, sweeter the resulting wine, later the drier. Then they bake the heck out of it (replicating those hot transcontinental voyages), maderizing and oxidizing the wine, Crazy process with delicious results!
Port is fortified with 77% abv aguadente and Madeira on the other hand uses 94% abv aguadente.
Does anyone know if there is a reason for this difference other than different local traditions?