Growing & Winemaking


Winemaker Interview: Dan Karlsen

September 2011
by Laurie Daniel
dan karlsen
Dan Karlsen, winemaker at Talbott Vineyards, says that Pinot Noir’s tendency towards refermentation led him to adopt filtration, which also prevents Brettanomyces.
When Robb Talbott decided to make some changes at Talbott Vineyards in Monterey County, Calif., he turned to Dan Karlsen, a winemaker with three decades of experience, most recently at Chalone Vineyard. Karlsen set about upgrading Talbott’s vineyards—Sleepy Hollow, in the Santa Lucia Highlands, and Diamond T, above Carmel Valley—buying new, gentler equipment for the winery and tweaking the style of Talbott’s Chardonnay and Pinot Noir to make them riper and more fruit-forward. He began as consulting winemaker in 2008 and was named winemaker and general manager in 2009.

Karlsen, who spent his teenage years in Sonoma County and worked briefly for the U.S. Forest Service in Oregon, eventually landed in 1981 at Dry Creek Vineyard, followed by Dehlinger Winery and Domaine Carneros. He spent 10 years at Chalone. He also has his own brand, Chock Rock Vineyard, which specializes in Chardonnay and Pinot Noir.

Wines & Vines: You filter all the wines at Talbott. Why do you think filtration is particularly important for Pinot Noir?

Dan Karlsen: I believe in sterile-filtering Pinot Noir, because it’s notorious for refermentation in the bottle, which seriously alters the flavors of the wine. I want all of my wines to taste the way I ultimately intended them to taste. There is a lot of talk about the impact of filtering, but in my three-plus decades of winemaking experience, I’ve come to the conclusion that filtration has a very minimal negative effect on wine flavor, if any, and I think that the unfiltered school of winemaking was largely created by winery marketing departments.

Filtration is particularly important for Pinot Noir because Pinot has glycosides, which are bound glucose molecules unique to Pinot Noir. The pigments in Pinot are very different than those in Cabernet Sauvignon and Syrah because of the way they bind glucose—and as a result, Pinot is much more likely to referment in spring, in the bottle, or to develop Brettanomyces. While I understand that there is a segment of the population that appreciates a certain amount of Brettanomyces, I don’t at all—and I won’t make a wine I personally don’t like.

Ultimately, when you filter, you get clear wines, and you avoid refermentation and the chance of Brettanomyces.

W&V: Why do you prefer crossflow filtration to other filtration methods?

Karlsen: Up until the mid-1980s, almost all wine was filtered through asbestos, and once asbestos could no longer be used, pads were essentially developed to mimic what the asbestos achieved. Pads and diatomaceous earth (DE) are still widely used and are relatively inexpensive, but I think diatomaceous earth is seen as somewhat antiquated these days. And while it is relatively cheap, diatomaceous earth is dangerous to handle. Pads can be effective, but not all systems are created equal. We like the Cuno system (now 3M Purification Inc.) and do use it on very small lots of wine, where crossflow doesn’t make as much sense. There are also other pad options, like plate-and-frame systems, but I’m not a fan of how much wine you lose to drippage with plate and frame. DE and pads are “nominal” filtration systems, which means they filter for clarity and they remove approximately 99% of organisms. This said, I think they also have the potential to impart more unwanted flavors to wine unless properly handled. For instance, we thoroughly wash all of our new pads to ensure that they don’t impart a paper flavor.

I like crossflow because it is an “absolute” filtration system. No organisms get through, and it adds no flavors. What makes crossflow different than other membrane-based systems is the way the wine interacts with the membrane. Instead of trying to push wine through the membrane (which is an issue because membranes can’t take too much sediment), with crossflow the wine is run tangentially along the membrane, and particles get washed away by the velocity of the wine. It’s basically a high-tech sieve that gets the job done in one pass, instead of several grades of filtration.

The other option is centrifugation, which spins the cells out. But centrifuges are very expensive, very noisy and quite high tech—with all the issues that come along with high-tech equipment.

W&V: Are there drawbacks to crossflow?

Karlsen: The main drawback of crossflow is that the initial cost is prohibitive for small producers. Also, crossflow cannot be used on non-organic stuff like bentonite. Like all filtrations, oxygen uptake is always a concern. To ensure that this isn’t an issue, it’s important to have a system with a nitrogen-sparging unit that blankets the wine as it is being processed to keep the wine from coming into contact with air and oxidizing. You also need to train people on the system, which can take a couple of days. It’s a complex system with a lot of piping, and there can be issues. This year, we had some wine that came out cloudy, and it took a lot of hunting and effort to figure out that a small valve had worn out. The more technical the equipment, the more that can go wrong, and the more you need to troubleshoot. When that’s the case, you need knowledgeable employees, not just another set of hands.

W&V: Do you have any tips for winemakers to make sure they get a good result with crossflow?

Karlsen: The most important thing is to make sure that you have a system with the nitrogen-sparging unit, which most of the new-generation crossflow systems have. Another great tool for the winery is a turbidometer to check the efficacy of any type of filtration. It costs about $1,800-$2,000 and will check to see if there is any haziness in your wine—even something that can’t be detected visually.

I think it’s worth repeating that current filtration methods all work well with minimal impact on wine quality. I use crossflow filtration because I think it makes for the highest quality wine. When you loo k around, most of the great wines of the world are filtered.

W&V: What is the cost of crossflow vs. other types of filtration?

Karlsen: It’s hard to do a real cost analysis. Crossflow is expensive up front, and pads are expensive to purchase. While diatomaceous earth and pads are the least expensive systems overall, and are the most accessible option for small wineries, the 3M Purification pads themselves are fairly expensive. I would estimate they cost about $2-$3 for a case of wine. The Pall crossflow system we use at Talbott is in the $150,000 range. In contrast, a centrifuge system might cost $400,000-$500,000. They also required a skilled operator. You don’t see too many centrifuges in American wineries.

W&V: How do you respond to critics, including some winemakers, who say that filtration strips too much away from a wine?

Karlsen: I don’t necessarily agree that it strips out any flavor from the wine, but even if I accept for the sake of argument that it does, for me, the quality benefits so far outweigh losing a small amount of flavor that it would be worth it. Would I lose 1% of flavor to avoid a cloudy wine or Brettanomyces? Yes! I think it’s also important to note that very minute amounts of sediment seriously affect the flavor, purity and character of fine wine. This is why we rack, decant old wines and riddle Champagne. Absolute clarity is absolutely essential for fine wine. If you don’t filter, you must do several extra rackings or use fining agents such as Isinglass or gelatin, which noticeably strip flavor. As an aside, it’s hell to filter. I wouldn’t do this if I didn’t think the customer gets a better product, a better wine across the board. Period. Cloudy, re-fermented wines suck.

A resident of the Santa Cruz Mountains, Laurie Daniel has been a journalist for more than 25 years. She has been writing about wine for publications for nearly 15 years and has been a Wines & Vines contributor since 2006.

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