Maceration is the process of soaking grape juice in the skins and seeds (and sometimes stems) for an extended period of time. This is done just following the crushing stage with the newly split skins and before any fermentation begins. The purpose of maceration is to leach tannins, flavours, and the colours out of the grapes and feed into the free flowing juices. Winemakers choose how long to macerate their grapes depending on which characteristics they wish to draw out, additionally they must decide at which temperature they will macerate at. Warmer environments will increase the speed of maceration but can also prompt fermentation to start sooner than necessary. Balance is key and the majority of winemakers have it down to a fine art of time and temperature.
The choice to perform a cold-soak maceration is to ensure fermentation doesn’t begin during the process. This is often performed in regions of Burgundy where Pinot Noir is dominant as the varietal has a lower phenolic content than most. Winemakers opt for a space around 5–15 °C, not a space in which oxidation happens naturally, allowing the maceration to occur up to 2 weeks before switching over to fermentation.
Maceration is most common within the red wine vinification process as they benefit most from the colour and tannin extraction, occurring for a week up to a month. This is where the deep red colour of all your favourite bottles arise from, the juice is not simply red from the moment it is crushed from the grape.
For the white wine process, it is less favourable to macerate as tannins are not enjoyed in a glass of white. The process often occurs in a matter of hours rather than weeks for white wine. If a winemaker does choose to macerate white wine grapes for longer the product is the elusive Orange Wine. The maceration darkens the light colouring and adds a tannic crunch that lays somewhere between a red and white wine. This is not dissimilar to the Rose process, as when red wine grapes are macerated for a short period of time (few hours/days), the ‘pink’ juices are run off and set up to ferment into Rose. The remaining juice is left to soak longer and form deep red wines.
The process of maceration only ends when the skins, stems, and seeds are removed from the juices. This means the process can continue all the way through the fermentation process if the winemaker wishes. Control measures within the fermentation process work in favour of red winemakers that don’t necessarily need (or want) strong tannins in their wines but still wish to leach out the colours for the stunning hues.
A term used for when the fermented juices are still left in contact with the skins, stems, and seeds long after the fermentation process is complete. Drawing out the last elements of flavour and tannins, this may seem like it would only cause more astringent tannins than anyone can handle. Yet, the extended period allows the tannin molecules to grow in size and therefore be less bitter with less surface area through the wine. Overall, it forms a richer yet supple red wine with extended ageing abilities.
Many would have heard this term used when referring to the fruit-forward wines of Beaujolais but not known the difference of it to the average maceration. It is the act of adding whole bunches of grapes (uncrushed) to the fermentation vessel, a common practice within Gamay wines. When left whole inside a heated carbon-dioxide tank for fermentation the enzymes within the grapes act as the catalyst and start to ferment the sugar within each grape. Once reaching around 2% alcohol content the grapes will split open on their own, then the following fermentation is driven by the yeasts added and pressing occurring to complete the process.