Just got back the ETS report on my single barrel of 2006 Pinot Noir and I'm very surprised and glad to see the chemistry. Here are the numbers:
Free sulfur dioxide -- 23 mg/L
Total sulfur dioxide -- 75 ml/L
Volatile acidity (acetic) -- 0.056 g/100mL
Titratable acidity -- 0.54 g/100mL
pH -- 3.54
Molecular SO2 -- 0.42 mg/L
I'm not a technical guy, but seeing these numbers really helps give perspective to what I've been experiencing, and thinking I've been experiencing, with this wine over the past year and a half. I wish I'd done a "juice panel" before fermentation to know the initial pH and TA. I'm not sure the measurements we did on this at the time were very accurate.
I thought the free SO2 might be really low. Instead, it's pretty close to where I want it for bottling in the next month. Total SO2 is a bit of a puzzle. I recently added 60ppm after the long malolactic fermentation finally concluded. I'm confident in my calculation, and the only other SO2 added to this wine was (I think) 40ppm at the crusher. Certainly no less, perhaps a bit more. So how do I only have 75 total SO2? Shouldn't total SO2 be the sum of all adds? I'll have to read up on that.
VA is both higher than I'd like, but lower than I feared. Actually, I have no idea about how much VA I should tolerate. I've just read Peynaud and he suggests keeping it below 55-60ppm. My wine shows some lifted notes that suggest a little VA. I want more purity in the wine. Maybe it's not VA. Maybe it's just the ripeness of the vintage. Seeing the VA at 56 ppm makes me think it could have been lower with a better ML. Yet, I'm relieved that it isn't higher. At this level, is it generally noticeable?
TA is about what I would expect, but given where I thought I started with pH and how the wine tastes, I would have thought my pH now was 3.7. The lower number simply helps me keep bugs out of the wine with less SO2. Meaning, molecular SO2 is very good, I think. I need to read up on this some more. Molecular SO2 represents the anti-bacterial properties of sulfur (anti-oxidation is the other main property). One table I found so far suggests I'm in great shape, but I'll read further before drawing conclusions.
Anybody have thoughts? Am I a slave to science? Or is this like putting a instant read thermometer in the bird you're roasting in the oven?
I'm hardly a technical guy