How much filtration is best for your wine?

Our traditional 'Kieselguhr' filter

One of the great conundrums of wine making is deciding precisely how much filtration your wine requires before bottling. Too little can leave the wine cloudy and possibly unstable, too much and you have a highly polished wine with little or no flavour. Purists may even argue that wines should be bottled without any filtration at all - commercially however, this would be a dangerous decision to make, or at the very least, something of a calculated risk.

In our Bodega we have two types of filter - a Kieselguhr (diatomaceous earth) filter, which uses a fine powder of siliceous earth to absorb particles in the wine. In more traditional cellars this is probably the most widely used system - it is not overly agressive and still leaves the wine clean enough to bottle with a reasonable degree of safety.

Our more modern, 'membrane' filter

The second type that we have is a 'membrane' filter, which as the name implies, uses a physical barrier through which the wine passes, rather like a very fine strainer. The level of filtration is determined by the density of the filter (or filters) used, and this is measured in microns. The finer the filter, the cleaner the wine - but also, possibly, the more bland the wine....

So, deciding the level of filtration is a fine balance - producing a wine that retains character and some body; but a wine that will remain bright and stable in the bottle.

Making a fine wine is not as easy as you might think!