Here are a few things about the ferment stage of red winemaking
Ferment on skins
After the red grapes have been destemmed and crushed, they are pumped into a tank ready for fermentation to start. While in the tank these grapes are called ‘must’. I like to allow the red grapes to undergo a cold soak for 2 days before inoculation with my preferred yeast strain. Cold soaking helps to remove colour and flavour precursors from the skins before fermentation begins.
During the fermentation stage, the yeast metabolise these flavour precursors and changes them to a range of fresh fruit flavours that you enjoy in your wine. Through experience I know that 2 days is optimum. I also have to think about getting the fermentation completed quickly so I can refill the tank with the next lot of grapes.
Tannins are extracted from the skins towards the end of fermentation. If I press the skins just before the end of fermentation, less tannin is extracted. The wine picks up more tannins when aged in barrels. This way the wine does not become too tannic.
Different yeast strains influence different flavour profiles and help the winemaker control the flavour.
During fermentation, carbon dioxide gas is produced. This carbon dioxide gas causes the skins to float. These floating skins are called the cap. We need to keep the cap moist otherwise it will cause bacteria to grow which will spoil the wine. We can keep the cap moist by hand plunging or pumping the wine from the bottom over the top (called a pump over). A hand plunger (pictured) is used to manually push the cap into the wine. It is hard work but in our opinion producers a better quality wine. Pump overs are good for evening out the temperature f the must in the tank. Typically the cap is 5-10*C hotter than the wine below.
- are typically fermented at warmer temperatures than white wines
- are usually fermented until all the sugar is consumed, creating a dry wine
- age for anywhere from 4 months to 4 years before being bottled
Before we press the skins, we drain the wine out of the tank. To remove the skins from the tank we have to shovel or bucket them out into our basket press. Its manual work but it is a labour of love.