Pressing Grapes

Generally, when someone mentions pressing grapes for wine most people will picture a barefoot group of people in a large wooden vat filled to the brim with fresh grapes gleefully stomping away. However, since the invention of the basket press in the Middle Ages, foot trodden wines have been on a significant decline for a variety of reasons, mainly production benefits such as yield and speed, but also for hygiene concerns as well.

But why do we press grapes? The easy answer is to release the juices in the grapes so that we can make delicious wine out of it. The not so easy answer is that pressing grapes is another tool in the winemakers toolbox. Depending on how much pressure we apply to the grapes, with our feet, basket, or bladder, we can obtain different styles of juice or wine. These are called press cuts. The first of these, while not technically a “press” cut, is the free run juice or wine. The free run fraction is the juice or wine that is already released and available before pressing. Generally, it is the most elegant and softest expression of the wine but can lack interest and grip. After being transferred to the press, the grapes or must are pressed through various stages with increasing pressure. For example, here at Harwood we generally press from .3 bar to .8 bar and finally 1.2 bars. At each stage we taste the resulting juice or wine for harsh phenolics and/or greenness. Here we make the decision to separate the press cuts from the free run or to combine them. Generally, we will keep the free run and press cut fractions separate and then blend them to taste before bottling.

Here at Harwood we use a 1500L Europress  membrane press. A membrane press works by inflating a large Kevlar™ membrane with air which gently presses the grapes or must against a perforated stainless steel wall allowing the resulting liquid to be released into the press pan below. Membrane presses give us a great deal of control over the pressure we want to press at and are very gentle allowing us to avoid damaging the bitter seeds found in the grapes. In all, pressing is a very exciting time at a winery as it signals both the start and the end of the harvest season and being able to taste the fresh juice or wine for the first time that year is always a great reminder of why we love what we do.

Loading the press with a ton of grapes…