What the F*** is whole cluster fermentation?
Whole clusters or GTFO! Whole cluster fermentation is something winos the world over are falling in love with, something they are drooling over. So what the fuck is whole cluster fermentation anyways? Well, to put it simply, whole cluster fermentation is when you process whole, intact clusters of grapes together, stems and all! All the berries are tossed in, along with the stems, and pressed together. So why is it such a big deal, and what does it mean to us wine lovers?
It adds character!
So what makes whole cluster fermentation so awesome? You have to understand what it is that adding the stems to the process of fermentation does to the wine itself. Fermenting whole clusters of grapes, stems and all, adds a lot of character to the wine that otherwise would not be there. The biggest impact on the wine's characteristics is to its tannic structure, as the stems are a rich source of tannins, so making wine using whole clusters is a great way of adding a little more oomph to the wine, and give it that nice velvet like mouthfeel.
Winemakers have also found that beyond tannins, whole cluster fermentation adds structure and flavors to the wine as well. You might get more savory, and spicy flavors and aromas that come from the stems like flavors of cinnamon, cedar, and black tea. This is a great way to add some balance to grapes that tend to overproduce in terms of juice. Think big berries with thin skins making super fruity, jammy wines, but now with some added spice and structure.
It brings out a grape's true self, amps it up
Fermenting the grapes as a whole cluster can also have the benefit of ramping up the characteristics of the wine to eleven. This is especially true for wines that are not typically made using this method. It emboldens a Syrah, for example, bringing those meaty, savory flavors to the forefront and thus making it a richer, more decadent wine.
The same can be said for lighter bodied grapes like Pinot Noir and Gamay, where the use of whole cluster fermentation has brought the true character of these grapes out for the world. In Beaujolais, where the process of using whole clusters is almost uniform across the region, it adds that touch of class to a vibrant, sexy, and fruity grape. Like adding a scarf to your look, it adds an extra touch of style that accentuates who you are. Pinot Noir is another light-bodied red wine that can be helped by the whole cluster, as the added tannins allow it to hold its color better with aging, meaning that the elegant Burgundy you bought will stay elegant for years, or decades even.
They better know what they are doing
Though the use of the whole cluster to make wine has existed since the ancient Romans first started making wine, today this process sits right at the crux of art and science in winemaking. That is to say, the winemaker should have the vision to use this tool, to know how to paint with this brush, and know exactly how it affects the fermentation process from a physical and chemical perspective. As we learned from Seven Fifty, the stems can create pockets of space in the tanks allowing oxygen to seep in and oxidize the juice at least in part. The berries are crushed under their own weight, so the yeast cannot penetrate the skin. But inside the berries' own enzymes will cause it to change and cause metabolic reactions, including the creation of alcohol (also known as carbonic maceration).
How a winemaker works with whole clusters is not so black and white, but rather like using black and white in an oil painting to create lighter or darker shades of a color. It is all about going forth on from the vision to creating an end product with the desired balance. For example, you may see winemakers use whole clusters in conjunction with destemmed grapes to create that balance, like adding an extra pinch of paprika to a recipe. We see winemakers combining destemmed grapes with whole clusters as a way of creating their desired product. Doing so shows the winemakers vision and passion combined with their deep understanding of the place, its effects on the grapes to create a wine that you will love. Sometimes its impressionist, sometimes avant-garde, but its always going to be delicious.