Red wine processing-whole berry tank fermentation

One trend gaining popularity in high end red wine production is the use of whole berry fermentation. Completely eliminate the crusher wheels on the destemmer. The act of destemming and pumping the berries will crush them to a small extent anyway.

One decision here was made at the inception of the winery, to eliminate the use of a must pump altogether. This was primarily a cost savings consideration. A must pump can be the single most expensive piece of equipment in the winery. With 3 inch tri-clamp ports a must pump can run $15,000. This for a piece of equipment you may only use several hours per year. Here, a stainless steel transfer vessel was built for a small fraction of the price. It holds about 1,000 pounds of destemmed fruit and is easily lifted by a standard size (for a winery) forklift.

At the bottom of the transfer vessel is a 6 inch hose connected via a tri-clamp fitting. Simply lower the hose into the top manway and whole berries will fall into the tank. It takes some working of the fruit in the vessel to empty it, but it's not particularly laborious, it's simply a matter of raking the fruit towards the port at the bottom of the vessel. Overall it's less laborious than setting up, disassembling, and cleaning a must pump.

The other thing you'll notice is the exclusive use of stainless steel tanks for red wine fermentation. This was also a winery design issue from the beginning. The alternative, which is popular on the East Coast, is to ferment in fruit picking bins. The most popular version of these bins holds about 0.75 tons of must. Wineries during October are typically filled wall to wall with them. If one were to purposely design a perfect fruit fly trap, these vessels of fermenting must would be it. Tank fermentations are a controlled, fruit fly-free environment that allows for things that can't happen with bin fermentations. The most important factor is heat. Heat is important for extraction in red fermentations and bins simply have too much surface area for their volume to retain heat. In a 60° F cellar, bin fermentations often top out at 77° F, too low for many winemakers. The other sacrifice with bin fermentations is the absence of the oxygenation achieved with allowing the fermenting juice to flow into a pumpover cart. Red wines love air early in their lives, especially during fermentation. It helps to fix red wine color and malolactic bacteria need some amount of oxygen to do their thing. Pumpovers are a hassle, but so are punching down bins. The tank seen here is about as small as any winery would have for red wine fermentations - 3,000 L. It can hold 2.5 tons of must. This amount of fruit would otherwise be spread over three bins. Tanks also allow for extended maceration. After the fermentation is over the tank can simply be sealed while the cap is allowed to fall over the course of several weeks. Try doing that with bins and you run the risk of spoilage issues.