Managing the fermenation

The principles for fermentation management are similar to those for white wine making, but with the additional complexity relating to the maceration dynamics:

  • Following the course of the fermentation by monitoring and logging reductions in density and changes in temperature
  • The control of temperature within the desired limits
  • Controlling the level of aeration of the must
  • Regulation and implementation of pump-overs and/or cap – punching in accordance with desired wine style and extraction levels
  • Determination and evaluation of the skin contact time; through daily tastings to follow the progress and extent of phenolics extraction.

When the level of phenolic extraction is deemed to be sufficient, the free-run wine is drained from the tank and the solid part of the vintage is pressed to release the press wine. Great care must be taken to avoid carbon dioxide poisoning if the solid faction has to be removed from the tank manually. The press wine may require a greater level of fining than the free-run wine, and so the two are usually kept separate until blending. It is important to note that there is often residual sugar, particularly in the press wine, and that this needs to be allowed to ferment out.

Pomace manipulation and pressing should be gentle in order to reduce the extraction of bitter flavours into the press wine. The final pressings may be particularly harsh and bitter.