Winemaking
How Port is made
Fast extraction, then spirit added mid-fermentation to stop the yeast and keep the sugar.
Overview
Because fermentation is cut short, there is far less time than usual to extract colour and tannin. Port producers therefore extract aggressively and quickly — historically by foot-treading in stone lagares, which is still done for top wines.
Neutral grape spirit is added part-way through fermentation, raising alcohol to around 19–20% and killing the yeast. The unfermented sugar stays.
What happens next splits the styles entirely: bottle-aged Ports (Vintage, LBV) stay dark and fruity; cask-aged Ports (Tawny) turn amber and nutty through slow oxidation.
Sources
Sources consulted
- Instituto dos Vinhos do Douro e do Porto (IVDP) — IVDP, Portugal
More in winemaking
Winemaking
Fermentation
Yeast converting sugar into alcohol and carbon dioxide — the step that makes wine wine.
Winemaking
How red wine is made
Fermenting grape juice in contact with the skins, which is where colour and tannin come from.
Winemaking
How white wine is made
Pressing the juice off the skins before fermentation, then fermenting the clear juice.