The Filtration Debate

I was in a tasting with about 40 winemakers last week, discussing production issues. Someone brought up the question of how to manage our unfiltered wines. One winemaker said "With Velcorin!" and another said, "Filter it, and then if anyone asks if it is filtered, it is only because they think that unfiltered is better, so then tell them that it is unfiltered, and they will be satisfied."

If your main motivation for not filtering is because you perceive that the trade or critics will like it better, then recognize that you are starting to let marketing direct your winemaking. These guys are capricious, and not filtering is a less than definite way to encourage their approval.

If you choose not to filter based on philosophical predispositions, be aware that it will likely require more intervention in the wine earlier on to minimize spoilage. pH must be low, SO2 must be maintained at levels high enough to discourage spoilage. Scorpion testing and plating should occur prior to bottling to know what microbes, and what levels are present. Turbidity should be below acceptable levels, or else further fining should take place to lower suspended solids.

Kermit Lynch is an importer who does a good job on so many things, including support for small producers, importation in cooled containers, and generally selection of high quality wines. He absolutely insists on no filtration in his wines, in many cases having a special non-filtered bottling made just for his own importation. However, I have found too many instances, especially with southern French and Italian wines that have been too Bretty to drink, have pressure and seepage through the cork, or which have rafts of spoilage organisms in the glass upon pouring it. That is unacceptable to me, and I only purchase white wines from him now, unless I have a chance to try the wines first. (I have never had a problem in a Chinon or Burgundy, I guess that these wines, from cooler climates have sufficient acidity to prevent these problems.)

Perhaps filtration got a bad name in the past, when the technology was haphazard, and the wines were exposed to oxidation or other problems during the filtration. I tend to filter pretty much everything via a crossflow filter, and we are able to keep O₂ pickup below 0.4ppm, which is similar to a simple racking. I can leave wines on their lees up until bottling, which further protects them; I think that this filtration is a tool that helps me to be LESS manipulative with the wines than if I didn't filter. We have done trials with crossflow vs. pad vs. DE vs. Velcorin vs. non-filtered, and the crossflow is much gentler on the ester chemistry of the wines. In some big reds, and in Pinot Noir, there may be some effect of the colloidial structure being different after filtration, due to proteins that are pretty big getting disturbed, and possibly removed. I don't know how to quantify this, but we have found that the wines come back together very well within a month or two. Velcorin seems to be pretty impactful on the wines, although it holds up well in big Cabernet Sauvignons and Syrahs okay. We haven't used it much more than for just trials.

I do know that we had a problem with a Syrah which was filtered to 1.5 microns going Bretty in the bottle, despite clean microbiology report at bottling (plating method.) This was before I was responsible, but we had to live with the consequences of a really slow selling vintage, and worry about reputation of the winery. We have gone to plating AND scorpions (more reliable, less false negatives,) and we stir barrels / tanks before sampling, as Brett can flocculate to the bottom of a container. We also test for 4EP / 4EG, but there can be Brett present without 4EP / 4EG, (but if it IS present, it means that Brett has at some point been active in the wine.)

I like unfiltered wine philosophically, but pragmatism wins out when our winery is trying to develop a strong reputation for quality and reliability. Just too much at stake, and there is no convincing argument to make me accept the risk.

(Maybe it is like the admiration for these guys who climb rock faces without harness or lines; I admire the elegance and skill, but heck if I'll try it!)

Quality: A Manifesto for Wine

The following came out of a discussion within a class I am taking at UC Davis. The topic was to define wine quality. (The strict structure resembles the many levels of Hell in Dante's Inferno, now that I look back at it!)

I have a difficult time accepting quality definitions that are fuzzy. In all other consumer products, quality control is very defined; not nebulous. In my opinion, when most people talk about wine quality, they are really talking about wine style; critics are always more concerned with wine style than quality, and they sometimes even rate wines highly for style without looking at their basic quality failures.

This generated some push-back from the class, with some great points made. I don't think it would be fair to the other students to upload their comments here without permission, so I will leave to to anyone who comes across this here to challenge my thinking. Please do so if you disagree, I am not afraid to rethink and refine my definition of quality in light of good points from others. And what does quality mean to you?

Cheers! -N.R. Carlson


--------------------------------------

What does Wine Quality mean to me?

I have definite prejudices regarding what is and what is not a quality wine. This tends to strongly influence choices that I make in winemaking, and sets off my alarm bells when clients or other winemakers favor winemaking philosophy over good practice and critical thinking. Here is my hierarchy of criteria, starting from basic wine quality, and progressing towards increasing quality. In my opinion, one may NOT skip over any of these criteria to the next level of quality without satisfying each point in the previously defined level.

1.) The first responsibility of a wine is that it should be stable when it goes into the bottle, and remain stable for the projected lifespan of that given product. If a wine cannot meet this basic definition of quality, it is a failure. This does not mean that the wine has to be sterile, but it does mean that it should not have active spoilage microbes modifying the sensory / chemical properties of the wine post bottling. SO₂ level should be sufficient to minimize oxidative degradation of the wine over its projected lifespan, and care should have been taken with the choice and screening of bottling materials and procedures to ensure minimal disruption of the wine on the way to bottle.

2.) If (and only IF) a wine meets the first criteria, the next step up in quality is that the wine should be well made and without obvious flaws, faults, and off aromas. This means that the wine should not have perceptible volatile acidity/ethyl acetate, sulfide problems, contamination by Brettanomyces, chlorinated anisoles, non-wine chemicals, or other non-wine aromas or contamination.

3.) The next step up in quality would be that the wine reflects the variety and / or appellation which it is labeled to represent. This refers both to basic chemical attributes, such as remaining within acceptable pH / TA / alcohol ranges, as well as to aromatic signature and phenolic composition. To me, it is preferable to blend / supplement / manipulate the must or wine as needed to achieve this basic definition of quality than to choose not to do so out of some inflexible, philosophical belief in ‘hands off’ winemaking. ‘Hands off’ winemaking is to be reserved for perfect fruit conditions ONLY! (The old adage is ‘God makes vinegar, Man makes wine.’) This is the basic quality level for wine as a viable consumer beverage.

4.) My fourth level of quality is that the wine should be a delicious, harmonious example of the style which has been chosen consciously by the winemaker, or which has been developed over time working with the site in question. Up to this point in my quality hierarchy, the wine could have met all of the above goals, and still be an unpleasant beverage. This is the first point at which I require the wine to be pleasant to consume. Worldwide, the great majority of wineries likely strive to operate in this level of quality.

5.) Which brings me to the next step in quality; doing the work in the vineyard to produce fruit which requires the absolute minimum in winery manipulation to achieve the above objectives. This level allows for wines that are less contrived, and more able to convey a sense of place and seasonal variation. Anyone who talks about ‘Terroir’ without achieving this level of quality is absolutely full of it. Brett is not ‘Terroir.’ Neither can a wine with excessive sulfides be considered an example of ‘Terroir.’ Wines blended from multiple appellations spread across vast distances have nothing to do with ‘Terroir’ either.

6.) My sixth and final level of quality would include such things as longevity of the wine, ability to develop interesting and complimentary secondary characteristics, and typicity specific to the place the wine was grown. This is where things start to become more idealistic and less objective. Where previously defined levels can be applied to wine as a simple consumer product, this is where I start to slip into wine as something more lyrical and worthy of legend and tradition. This is the level at which the best estates operate in the best of vintages, where you will find Grand Cru Bourgogne and Alsace and the very best German wines at. This is level at which a very few New World wineries operate as well. This is the level of wine quality that inspires me, whether or not I ever actually am able to attain it in the wines that I work with.