What are the pros and cons of filtered versus unfiltered wine? Well, let’s find out from an expert, German winemaker Kim Kirchhoff.
Wine is not only a drink, but also a kind of play. It is a subject, a hobby people like to discuss or exchange their knowledge, thoughts and news on or about. And just as with any fashionable hobby, it’s subject to trends and techniques.
One big thing happening in the wine industry right now is the trend of unfiltered wine. See it as you like – natural, authentic, back-to-the-roots kind of thing: healthy. The idea of unfiltered wine is quite perfect for the overall “natural” fad of the moment.
Filtered vs Unfiltered Wine: What’s the Difference?
Let’s understand what’s going on technically between filtered and unfiltered wine first so that you can understand the differences between the two. As a winemaker, I’ve found that there’s a lot more to this subject than first meets the eye.
Why wine is Filtered
First, a lowdown on filtered wine. When wine finishes with fermentation, it is full of floating yeast and sediment. It’s what we call “blind” (you might refer to it as “cloudy”). This unclear wine is normally purified or filtered. That is to say, the yeast particles and microbes are separated from the wine before bottling. We do this with filtration. Wine typically goes through two filtrations: once for sifting out the yeast to clarify the wine, and the second is for removing any bacteria before bottling.
Which wines are nearly always filtered?
Unfiltered wine skips the filtration step, but this doesn’t mean that the wine stays cloudy. Instead of filtering out the yeast, the wine simply rests for a time (no shaking or moving the tanks!). This naturally settles the yeast particles through gravity. After this point, the wine gets racked from the lees. Racking is where we siphon off the clear wine from the cloudy wine at the bottom of the tank or barrel. It results in clarity about the same as filtered wine.
Do those small particles left in unfiltered wines improve the taste?
For the most part, unfiltered wines have the same clarity as filtered wines, so the remaining particles contribute minimally to the body of the wine (scientifically speaking, that is).
Which wines are more commonly available unfiltered?
Unfiltered Wines are Risky Business
Not to say that unfiltered wines are bad; many are great. However, what happens during the second filtration is very important.
Keep in mind that from a biochemical point of view, wine is nothing more than a beverage in limbo between juice and vinegar. Meaning finished wine is not a stable medium as it’s in a constant state of change. Also, it’s in danger of going bad. Any bacteria remaining in the wine increases the risk of spoilage.
Therefore we can either remove bacteria by filtration to eliminate microbial activity (the conventional way, or allow for the presence of bacteria, suppressing their activity in other ways (the unfiltered way).
This suppression can be done in the second fermentation (called malolactic fermentation) so that nothing will happen in the bottle anymore. The wine loses its primary fruit flavours and freshness, but transforms into a nutty, creamy kind of wine.
The other option would be to stabilize an unfiltered wine with a higher dosage of SO² (sulphites).
Filtered vs Unfiltered Wine: Co-Existence is the Answer
It could be that unfiltered wines are more “open” and “natural.” But as we’ve learned above, it depends.
Both techniques should be accepted for peaceful coexistence. Everyone should try out both styles in a tasting to create a personal preference and opinion. We suggest that you do it in a blind tasting setting!
(Source: Wine Folly)