Taking the SO2 Plunge

New pH meter

Got a pH meter + Flawless

In the interest of being more precise in my knowledge of my own wines, I bought a pH measuring devise a couple months back. I hadn’t used it so far on the Petite Sirah and I was starting to think that I might not at all. After all, what would I do with that information? I knew that the pH level can be indicative of the sensory aspect of a wine, but I don’t want to be messing around with that too much. I also knew that the pH level is a factor in determining the amount of SO2 to add to the wine, but I hadn’t decided where I was going with the SO2 approach just yet.

In parallel, I’ve been reading Flawless, by Jamie Goode. Goode is a writer who’s at the very least, natural-wine-adjacent, or has an open approach to those techniques as potential methods for creating good wine. So, I undertook that book to educate myself on some of the chemical origins of common flaws in wine, to improve my own tasting knowledge and maybe help out my winemaking on the side.

Going through the sections on brett and oxygen management gave me a fright though. Would I risk my entire batch by underdosing or not dosing with SO2? Doing so would certainly be the safe approach. I also considered the fact that I know nothing about the vineyard or growing conditions of the grapes I used and I already used commercial yeast, so to pursue some zero-zero dream by holding back SO2 just wouldn’t work.

So, I decided to take the SO2 plunge.

Doing the measurements

I researched different charts for the addition of SO2 based on pH levels and found a few that generally seemed to agree with each other. Yesterday, I went down to the basement and used the Titrets to measure the current free SO2 in the RP-15 and D21 batches.

Titrets is barely useful with a red wine, I’ve learned. From the best I could tell, it was saying that the wines had 35 and 30 ppm free SO2, respectively, when I hadn’t added any. That does not seem right. But, it’s all I have to go on. I then tested the pH. Both carboys came in at a little above 4 — 4.06 and 4.13! This also seemed quite high! According to the SO2 charts I was using, I needed to be aiming for 78ppm free SO2.

OK, so weirdly high free SO2 and weirdly high pH. I still have no idea what all this means, but I’m just trusting the numbers I’m seeing at this point. I added SO2 to bring these guys up to about 75ppm (my measurement tools are still not very precise) and put the airlocks back on.

Now, I’ll wait a couple months before seeing what’s going on in there.


Tasting

I also got a chance to give them a try. The D21 tannins have softened a bit, which is good to see and the RP-15 remains comparably fruity. I’m thinking I’m leaning toward keeping them separate at this point.

More waiting

I guess the slow part has kicked in. Right now, I’m just sitting and waiting.

After the last racking, there hasn’t really been any sediment collecting and I don’t see any reason to touch it for a few months.

I spoke with a winemaker recently, who confirmed the “leave it” approach, but also suggested that one way to deal with the tannins would be to agitate the carboys somehow. So I may be giving that some thought.

Anyway, here’s to the slow!

Petite Sirah So Far

A little later than I had planned, but I racked the wine yesterday (Saturday) to get it off the residual yeast. It also gave me a good opportunity to see how things are progressing. The two yeast batches are definitely on different tracks.

To rack them, since I only have two 5 gallon carboys, I needed to rack them into a sanitized bucket, clean/sanitize the carboy, then rack it back in. To top them off, I used the excess wine I had put into one gallon jugs.

In the end, after topping up with the appropriate yeast batch, I combined the two excess jugs into a single one gallon jug. Keeping them separate would have left too much headroom and for future toppings-up I figure any residual fermentation will be completely done and all the available sugar gone. But I had slightly more than a gallon left, so I also got a half bottle which I combined with the the clearer dregs left after the rackings, to get a rough blend that I started drinking last night (more on that below).

Continue reading “Petite Sirah So Far”

Pressing and Waiting

One casualty of the pressing

Last weekend was a little too busy with winemaking to do much blogging. So, a lot went down!

Last Friday (10/4), after a week and a half of fermentation, the bin running with the D21 yeast had reached 1.000 specific gravity, so I figured it was time to press. Immediately after taking the measurement, though, I had my doubts. I had taken the sample from the top of the bin, and since alcohol rises in water, I figured I may be biasing my sample a bit. The must was still foaming when I punched it down, telling me that it was still going, so that lined up.

Despite my reasonable doubts, I was still going to press the next day though. The RP-15 was starting to taste a bit tannic, so I figured it would be good to get it off the skins and stems. I bet that the downside would simply be that the wine would be lighter than a typical Petite Sirah, which was a risk I’d take over having it sit unprotected, not-fermenting.

Continue reading “Pressing and Waiting”

Let the 2019 Wine Begin!

Did not end like that poor woman from the video

The 2019 batch is well underway! I picked up the Petite Sirah I ordered last Wednesday at Oak Barrel Winecraft. They were super helpful and hardworking there, so I’m grateful for their assistance. Since I have this job thing, I had to head into the office after dropping the grapes off at home. But, when I got back that night, Tressa volunteered her feet and stomping power and crushed the grapes while I provided some degree of balance.

Is This “Partial Carbonic”?

My thinking with the foot crushing: I’m giving whole cluster a try since the stems seemed reasonably mature (i.e. primarily not green) in the batch and I wouldn’t mind if a good number of the grapes stayed whole and got some carbonic fermentation action going down. Now, I could be completely wrong about whether any carbonic fermentation will occur (maybe the partial foot crushing sufficiently damages nearly all the grapes), but I do like the idea of the yin/yang of carbonic/whole-cluster. It sounds like it could produce something interesting.

Yeast Choices

Also on the experimental front was my yeast choice. I didn’t want to use native yeasts since I don’t really know much about the growing environment for these grapes, other than that they were grown somewhere in Lodi. So, I did some research on what yeast plays well with Petite Sirah. I came down to two candidates: RP-15 and D21.

D21 getting started

I liked that RP-15 was a California-derived strain, scratching my local itch. It also has a reasonably high alcohol tolerance, which means there won’t be too much residual sugar and increases my freedom to take a lower-intervention approach when it comes to SO2. In turn, I liked the D21 since it has a similar alcohol tolerance, but it also reportedly reduces herbaceous elements in the wine. Since I knew it was likely I’d do a whole cluster thing, this seemed like a useful trait.

So, which to choose? The local yeast or the one with the handy trick? I chose both. I’ve got 100 pounds in one Brute with the RP-15 working and another 100 pounds in a second Brute running with the D21. I’m still not sure if I’ll keep them separate or combine them after pressing. I’m tasting them every couple days and so far the RP-15 is developing in more of a fruity direction while the D21 is tasting kind of creamier. We’ll see what happens.

The dual-yeast approach does make punchdowns more difficult. Each time I go down there to do a punchdown, I’ve got to sanitize the potato masher between batches to avoid the yeasts from entering the other Brute.

Punching it down

The Numbers

As for the numbers, this started at 23.9 Brix, 3.71 pH, and 0.67 TA. I’ve had some trouble getting enough of the juice into a thief to take a specific gravity reading since fermentation kicked off, so I’m going to have to figure that out somehow.

Low(ish) Intervention

I can’t really claim to be taking a low intervention approach when I’ve pitched commercial yeast, but I would like to avoid any additional additives or corrections. So the acid levels I have are the ones I’m stuck with. And, on the SO2 front, I’m going to try to limit it to the same 20ppm at bottling approach I took with the Riesling.

As with all things, this could change, but that’s where I am not.

Grapes on the way

I’m back from my travels and, as expected, my narrow options for unpressed white grapes had withered on the vine (grape jokes!). But, I’ve put in an order for two hundred pounds of Petite Sirah from Oak Barrel Winecraft, that should be coming in this week.

So, that means it’s back to the drawing board for plans, but what I’m thinking right now is to give whole cluster fermentation a shot (provided the stems aren’t too janky). I’d like to keep it on the skins for longer than I did with the Zinfandel last year as well.

Other than that, I’m an open book. I don’t think I should rely on ambient yeast, since I don’t really know the origins of these grapes too well. Maybe I’ll give BM4x4 another try, or maybe I’ll give that D-47 a go, even though it’s typically used for whites. (I should probably get that test batch out of the closet!)

Anyway, good times ahead!

Bad Harvest/Trip Timing Luck

Well, so much for my plans for that skin-contact white.

I’m headed out on a trip at the exact time my grape source plans to harvest, so won’t be able to get the grapes from them. Looks like my other potential sources are only going to be harvesting reds by the time I return (if I’m lucky) as well.

But, no matter. If I can get my hands on any grapes, that’ll be a victory.