Rim Variation, Gas Evidence, and Sediment

Hey Readers!!

I have to be honest, I had pre-planned most of my post topics with very little consideration for possible events that would correlate with my subjects. To my surprise, so far this has definitely worked out in my favor!

This week I want to talk about Rim Variation, Gas Evidence, and Sediment. These are three very different topics with very different causes, so hopefully this flows well. If not, I’ll break it up. I have the fantastic opportunity to express two of these three topics with evidence from a vertical tasting I will be attending tomorrow at Barboursville Vineyards. If you have never been to a vertical tasting I highly recommend seeking one out. They can be a bit pricey to attend, but it is a great learning experience and it is a fantastic opportunity to determine if you enjoy aged wines or younger wines.

Rim variation is the difference in color from the center of the class to the edge. Sometimes this can be pronounced, sometimes it can seem to be non-existence. Either way, it tells you a lot about the wine. Rim variation can indicate age of the wine, oak contact, as well as hint at varietal. Rim variation occurs naturally, however, the color and how that color is influenced plays a large part in how evident the variation is. Young wines will present with minimal rim variation, perhaps looking clear only for a millimeter at the edge while everything else appears ruby red. Older wines can show a gradation from the rim to the center. It can be very difficult to determine rim variation in white wines, however it can be evident in older or oak aged white wines that have a deeper color or orange hue.

My favorite evidence of rim variation is the Nebbiolo grape. This Italian varietal, named for the fog that hovers over the vineyards at harvest, creates a beautifully earthy wine with a light color and strawberry and tobacco notes. This most notable thing about this wine’s color is the golden rim evident in the glass and on the pass through when held over a piece of white paper.

In food, rim variation can occur in all sorts of products. Some types of produce, like Idaho potatoes and kiwi fruit have brown skins and different colored flesh. This is caused by a separation of nutrients between the flesh and the skin of the food as it ripens. In many cases, this means that the skin and flesh have different nutrients. Often, as is the case with potatoes, the skin has more nutrients than the flesh and should be eaten to help get all of the required daily nutrients.

Gas evidence refers to bubbles, so think champagne. Usually caused by a secondary fermentation either before or after the bottling process, bubbles indicate evidence of gas in wines. Secondary fermentation can also happen unintentionally, in unfiltered wines with high residual sugar and fewer sulfites. (Sulfites act as a natural preservative). In this case it is thought to be a fault of the wine because it is not an intentional characteristic.

It is important to note here, also, that bubbles in wine do not indicate anything about the flavor. Bubbly wines can range from syrupy sweet to bone dry, come in every color under the wine rainbow, and cover a similar range of flavor structures.

In food, gas evidence indicates much the same thing, chemical processes having occurred to create bubbles, though in foods it is harder for them to escape to the surface. You see this a lot in processed foods like cheese and baked goods, but also occasionally chocolates and some sauces. Many times this is a desired effect, like with Swiss cheese which is exposed to a specific type of yeast. Bubbles in bread products can also determine the quality or style of the bread. Croissants are meant to be light airy and flaky, which is often a product of both production style and the yeast working in unison.

Sediment occurs naturally in wine and foods, particularly those that have been aged for a substantial amount of time. As we discussed in an early post, it is the physical evidence of naturally occurring chemical reactions as little particulates in your wine and food. In wine, it is generally the result of unfiltered skins and pulp, though I have also seen sediment form in unfiltered white wines as crystals. Sometimes it is crunchy and others it is soft. The primary food example of sediment is once again cheese, in many aged cheeses you may find a crunchiness on the palate which coincides with a particular saltiness. This is because as the cheese ages the salts solidify throughout the product, creating the flavor, mouth-feel, and sediment that are unique to each genre of cheese.

Coming up: I will show you some examples of these effects in action! Next week we talk about Extract and Legs.