| Winemaking |
| Fermentation Process: |
| Over 3 days, half the sugar content of the grapes is converted into alcohol, at which point the fermentation is arrested. The fermentation is stopped by the addition of 144 proof neutral, clear, grape spirit. 450ml of fermenting must requires 100ml of neutral grape spirit. The grape spirit kills the yeast and Porto is formed. |
| Piston Fermenters replaced Pump-over vats in 2001: |
| It took 11 years of empirical analysis and experimentation, analyzing the vintage foot - treading techniques to create a fermenter that could replicate the human process. The specific shape was designed to create the best rotational movement and contact with oxygen for optimum extraction. The circular design also prevents 'dead-zones' forming in the fermenter. The piston fermenters obtain higher concentrations of phenolics and anthocyans that are indicators of an excellent extraction. Piston fermenters gently break open the grapes and thenextract all the fruit flavors, color and tannins; leaving behind the unwanted green tannins. This method is only used for premium non-vintage Portos. |
 |
 |
|
PUMP - OVER FERMENTER [ Old Method ]
|
|
PISTON FERMENTER or Port-Toe [ New Method ]
|
|
|
|
