Physical-mechanical method (also filtration, filtering and filtering) for the separation or purification of substances such as liquids or gases by means of technical filtering devices. Different filtration processes are a common process in the winemaking, Already in the antiquity there were at the Egyptians. Sumerians and Romans a technique in which wine was filtered by means of cloths or similar material. In the Middle Ages were added with acting as a filter piece of muslin fabric flavoring Spices filtered out of the wine. This piece of fabric was called "Manica Hippocratis" (sleeves of Hippocrates).
In today's viticulture the filtration mainly concerns grape and young wine, but also for the purpose of air disinfection and water, The purpose of this method is to remove unwanted substances and thus to stabilize or sterilize the grape must or wine. As a rule, this is done in several steps. First, the quite large ones created during pressing lees (Pulp) removed from the must (see under degumming and clarify ). Only so the so-called filter maturity of the wine is achieved as a prerequisite for the respective Filtrationsart. This means that the wine must not be too cloudy. A subsequent step is the removal of microorganisms as yeasts and bacteria,
However, not only those particles are retained by filters which (as one might assume) are larger than the filter pore size. Because that's just one of the effects. Other mechanisms include particle inertia, diffusion effects (thermal movement of particles), electrostatics with adsorptive Effect or barrier effect. Therefore, in principle, particles are deposited, which are far smaller than the pore size of the filter. In any case, filter pore sizes of ≤ 1 μm (millionth of a meter) are required (human hair approx. 40 μm).
Filtration can be done several times at different stages of winemaking, especially after Press (Most), after the fermentation as well as immediately before or at bottling, As a rule, several of the methods listed below also take place in combination. However, filtration always means a more or less strong mechanical load of the wine, it can also (too high) losses of flavorings or carbonic acid result, therefore, this method is to be carefully applied. In case of improper or too sharp application, this may be the...