Welcome back. In the previous lesson, we discussed formal wine-tasting setup. In this lesson, we'll have a look at wine clarity. So let's go back to our concept of wine tasting versus sensory evaluation of wine. In order to do really good reproducible thoughtful sensory evaluation of wine, it's best to learn a procedure step by step. So let's examine the parts of such a procedure. To evaluate the clarity of a wine, it's important to be able to see through the wine. Clarity of a wine is really a function of how well light is transmitted through that body of liquid. If light passes through without bumping into anything so to speak, the beverage, the wine that we're looking at looks very, very clear. It's more difficult to see clarity in a red wine than in a white wine, so it's useful to have some type of a light that we can use, backlight or hold our glass up to light coming in a window. Let me make a couple of comments about the proper setting for wine tasting and especially for clarity and color evaluation. We need to have a good source of light. Traditional incandescent light bulbs provide a pretty good source of light. The best overall full spectrum light source of course is the sun. But we can't be outside with all the distractions that that involves, and we certainly don't want to hold the glass up and look directly into the sun. So it's best to have indirect sunlight if possible coming in through a window. But if we're in more secluded wine tasting situations, such as a tasting booth or a tasting panel, it's best to have that good source of light. I've tasted wine with fluorescent light as my light source, and traditional fluorescent light has big wavelengths, has big peaks in the green and blue wavelengths, and not much in the red or the ultraviolet. So it gives us a really distorted view of color. Best to have balance in the spectrum of light that's shining on the wine so that we can see everything that the wine might have. It's also best to have a white background, not a glossy white background but a matte finish white background. I find that copier paper works just fine. So spread it out, get yourself a good light source, a good old fashioned light bulb, and tip the glass at a 45-degree angle away from yourself, and look down through the thick part of the liquid, what we call the core, and then also move your eyes and look out towards the edge of the liquid, the thinner part as the wine travels forth in the glass as you tip the glass. In the case of a white wine, you'll be able to see fairly readily if there is any problem with clarity. The terms we use for clarity are clear if the wine is clear. If it's slightly off-clear, we might say that the wine is dull. Less clear than that, we might use the term hazy or cloudy, any intermediate level. For example, we may say hazy plus, hazy minus, clear minus. Many tasters like to talk about the reflectance of the wine and how light place through the wine, and they use the term bright side-by-side with the term clear. In my vocabulary, clear and bright amount to about the same thing. Some tasters think that a bright wine must be a little bit clearer than simply clear. The word brilliant is reserved for wines that truly stand out from others in their category. So for example, if I were to pour eight glasses of Sauvignon blanc for you, and you looked at all of them and they were all perfectly clear and bright, but one of those glasses seem to be far brighter than the rest of them, I would reserve the word brilliant to describe that glass. Different systems of tasting use different levels of brightness between bright and brilliant. But we won't go into those at this point. If you see something floating, it's likely to be a piece of cork. If you see something submerged along the bottom of the liquid, it could be solidified grape particles remaining in the wine. It could be bitartrate crystals, it could be other particles that got into the wine from the barrel. It could be dead yeast cells, dead bacterial cells and so forth. For the most part, modern wines do not have this sediment, particularly if they're young wines. The one that you'll see most commonly, particularly if you had that wine in the refrigerator for a few weeks, will be tartaric acid crystals, otherwise known as potassium bitartrate crystals. With a red wine, it's a little more difficult to ascertain its clarity. Certainly, can be done by again tipping that glass of wine in a 45-degree angle away from you with a reflective white surface behind the glass and looking through the core of the wine, but also the shallower rim of the wine to see if there are any sediment or any particles. I often keep a small flashlight handy, and if I think it's necessary, I'll hold that flashlight behind that body of liquid and the glass to see if the light shines through it. Very often, a wine that looks perfectly clear will show itself to be slightly hazy when you shine a flashlight beam through it. It'll look like your automobile headlights when you're driving in the fog. I am rather forgiving of large range of clarity or a lack of clarity in white and red wines. I know that many wines are bottled unfined and unfiltered. Fortunately, many of them tell you on their label that they are unfined and unfiltered, and that implies that you may find some off clarity, some haziness in the wine. There's absolutely nothing wrong with that. Also, please remember that wine is a natural product made from an agricultural crop we call grapes in a food processing plant that we call a winery. As such, as a natural product, wine can degrade over time. So even if a wine has absolute prismatic clarity, when it's first bottled, if you keep it in your possession for a few months or a year or two or longer, particularly in the case of a wine that you know you want to age, just assume that it's going to lose clarity very gradually as time goes by. Elements in the wine condense, and crystallize, and dropout. In fact, if your wine is more than 10 years old and it doesn't have sediment in it, I'd be a little suspicious. With older wines, sediment is almost a guarantee of authenticity. In this lesson, we looked at wine clarity. In our next lesson, we will turn our attention to wine color.
