I remember thinking in my high school chem class that a person had to have that special bond with science in order to understand what was going on. In short, I thought they had to have “chemistry” with chemistry. What I’ve been slowly learning at the winery is the impact that everything can have on how that bin of juice becomes a healthy and ageable wine. It’s all connected like a story. It’s easier now for me to see how chemistry and the concept of “terroir” are similar, only one has more tangible, anticipated results while the other’s results have been described as being based on variables that may or may not be there year after year. One is more definable than the other. Here are some chemistry highlights that I’ve found fascinating so far during my internship.
- The environment that the bin sits in can give false temperature or Brix readings. I remember when we had a few bins of newly destemmed grapes resting near the rollup doors, given that Ed’s facility is extremely small and we were at max capacity with bins. Because these doors receive more exterior heat from the sun outside, if you took a Brix reading from one of these bins whose corner was closest to this door, you’d get a much warmer reading. Therefore, it’s best to get a more accurate reading by working with a corner from the opposite side of the bin that’s been exposed to the cooling system of the facility.
- The “cap” is formed by CO2 pushing grapes up to the surface.
- So, apparently that buttery/coconut-ty oil, way-too-bright fruity aroma in wine means that it’s going through secondary fermentation, which is a process called malolactic. However, to me, this smell has always been moderately repulsive. It smells like cheap suntan lotion. I’ve smelled it a number of times in really young wines or wines that are akin to what I like to refer to as CS (“corner store”), but I never actually knew it was due to malo. I also didn’t know that ALL wine can naturally undergo malo if conditions are right (ie; In order for malo to happen, it must occur in young wines not yet settled and with higher levels of acid because these microbes grow to soften or tame high acid. And although I dislike the smell of it, malo is kind of a cool process that wine takes on to balance itself). Weirdly enough, naturally-occurring malo has been sort of blacklisted from the topics of conversation because it’s been falsely perceived as something that producers manually do to their wine to make it have a creamier mouthfeel. Really puts the mal or “bad” in malolatic, doesn’t it? Apparently, this second fermentation occurs a little less noticeably (ie; no big foamy bubbles on the surface as you see during primary fermentation). Malo also creates a quiet oily sheen on the surface of still-settling wine, which is a good way to see if its underway. That said, you do need to test the acid level to determine when the malic acid has converted into lactic acid to the point of about 0.25 L/g or less or you might risk bottling your wine too early and discover some corks a-poppin’ later on. Finally, I also never knew that if you choose NOT to SO2 your wine, malo is less likely to occur on its own.
- Okay, so this is pretty important…you should really only add water to a bin once and after a day or so beyond when the fruit was originally destemmed because as the fruit soaks in its own juice during this time, additional sugar may bleed out from skins or stems that wasn’t initially detectable. This would make your original Brix reading lower than it actually is. Wait to take your initial Brix reading a couple of days in and then add the appropriate amount of water.
- Apparently, there is a formula to adding water as opposed to just guessing at how many 20 L buckets of water to toss it. The basic formula for adding water is (volume of juice) x (Brix of juice) / (desired Brix) = (needed volume after adjustment) and, (needed volume after adjustment) – (volume of juice) = water to add.
- Do not over press the fruit when putting it through the press. Wine is a food, and much like bread, does not do well when overworked. In short, it might extract tannin you don’t want (think of the varietal you’re working with such as say, Pinot,…that wouldn’t be desirable!) or even off flavors. Taste a sample or two of the first-run pressed juice as it drains into the tray. If you are picking up a little of the above, that’s an indicator to stop.