Filtration for Crystal Clear Wine?

OK, maybe not many people stay awake nights thinking about wine filtration, but this is often times an important part of the winemakers bag of tricks to produce wines that are clear and appealing as well as sterile and stable. We’re going to look at a couple of aspects of this technique and maybe revisit for a more in-depth look later on.

To start, let me say that not all wines are filtered. Some producers make a point of stating this on the wine label. What does this mean? This means that the wine is not filtered. DUH! It does not guarantee quality or a level of quality. It means what it says: This wine is not filtered. Period. There are some winemakers who believe that a wine should never be filtered as all of the particulate components of a wine add flavor; filtering a wine reduces overall flavor and complexity.

There is also fining-this is a process whereby, traditionally, some material is allowed to filter through the wine to remove certain particles and compounds that may cause a wine to cloud. Some of the most common fining materials are: bentonite,a type of clay from Wyoming; kaolin, another clay; silica and activated charcoal. These are inorganic agents.

Organic agents include albumin, casein, gelatin, and rarely, isinglas from fish bladders. These agents work largely by forming compounds with solids in the wine, called colloidal particles, and add weight to them so they settle to the bottom of the cask.

Much of this settling action happens if a young wine, fully fermented, is left to settle on its own time. But time is money and fining gets the wine hopping along its journey to your table faster than waiting for it to settle of its own accord.

Filtration can be performed almost anywhere along the wine making process: wine is often filtered after fermentation when the wine is racked, transferred from one barrel to another, to start the aging and settling process. This is a coarse type of filtration and removes only the largest of the wine solids.

Modern filtration is either depth filtration or surface (AKA absolute) filtration. Depth filtration has the wine pass through a reasonably thick filtering membrane or agent. Solids get trapped somewhere in the channels of the filter and do not pass go and do not collect $200. Bummer.

As the name suggests, absolute, or surface, filtration removes everything if the filter holes are small enough. These holes are on the surface of the filter and need to be removed when clogged. This type of filtration can have openings so small that even bacteria and yeasts are filtered, hence, absolute filtration.

There are myriad variations on filtering agents and filtering machines, so we can come back to this topic if you would like. Let me know.

So next time you hoist a goblet of vino, hold it up to the light and see just how beautifully clear this wonderful beverage is; and realize that it takes lots of skill and experience and love to produce this product.

A Trip to Napa

The last week in September I was lucky enough to enroll in a course, a wine course, at the Culinary Institute of America Rudd Center in Napa Valley. The Rudd Center is a portion of the facility located in the heart of the valley. While the main part of the entire facility, the old Christian Brothers Winery, is devoted to culinary study, there is a separate building on the property that is concerned with wine study. After all, wine and food were born together and make ideal study buddies.

The course, Great Wine Regions of Europe II, focused on the Loire, the Rhone, South of France, Austria and Greece. It was presented in the state of the art amphitheater style classroom that can accommodate around 30 students. The presenter was an extremely knowledgeable Master Sommelier by the name of Bob Bath.

There was lots of information presented, about 24 wines per day tasted, and a good group of folks to hang with. With breakfast and lunch included, nobody starved.

What is important about this facility is that the same level of professional expertise is demanded for the wine studies as for the culinary and baking programs. The CIA offers a Wine Professional Certificate which requires a high level of knowledge of wines, service, wine business and food and wine pairing. To my knowledge, this is the first facility of its kind in the US. And when I asked my classmates why the CIA was chosen for study, certainly there are other wine education programs around, the same answer came through-quality of educational experience and knowledge of the instructors. The fact that the Rudd Center is located in the heart of Napa Valley and is drop dead gorgeous as well, certainly didn't hurt.

A long time ago I graduated from the CIA in Hyde Park, NY with a degree in Culinary Arts. For the longest time I wanted to get to the Rudd Center as my teaching and learning focus has drifted towards wines over the last few years. I finally made it and intend going back next spring if at all possible.

Good place. The photo is the front door to the Rudd Center.

Spain and Portugal

This past Sunday my tasting group and I were scheduled for wines of Spain and Portugal, light wines as the Brits say; table wines as we Americans say. One of the great aspects of the Wine and Spirits Education Trust program, is that, over a couple of years, I tasted wines that I never before knew existed. And as part of my Diploma study course, we taste wines from all over the world for Unit Three, Light Wines of the World.

Beyond the “regular” and familiar wines we ventured into: Rioja Reserva, Gran Reserva, a red from Navarra, a red Duero, a white from Rueda, made with the Verdelo grape which is responsible for the verdelho style of Madeira, but here fermented bone dry and crisp. There was a wine from the Duoro River Valley where port grapes are grown. But this was a scrumptious red table wine using the Tempranillo grape and the Touriga Franca, which is one of the top five quality grapes used in producing the exquisite fortified Ports I love.

A Vinho Verde delighted with its low alcohol, early fruity taste and its wonderful fizzzzzzz! And of course, there was a strwawberry/raspberry scented rose′ from garnacha grapes from Rioja.

What impressed the group was the fine quality of the wines-not a dog among them. In fact, most were exceptional. And when the price was factored in, they were all great values. We taste blind and do not reveal labels and prices until after all wines are tasted.