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.
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.
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.
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.
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.
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.
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!)
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.
A week ago, there was still too much gas still escaping from the Riesling kit I had started this spring. When I was checking again throughout this week, the bubbles accumulating on the edge were dissipating at a healthy rate. I figured with the two more rackings I had planned (which ended up being three) the degassing would be enough.
To SO2 or Not to SO2
I also bought a Titrets kit to test the free SO2. After all my handwringing about whether to add SO2 or to take the full no-additive route (I hadn’t added any of the kit-provided powders and solutions up until this point), I decided that I would only add SO2 at bottling and only to the level that it would still be accepted on the shelves of purists like The Punchdown over in Oakland (great place btw). That meant 20 parts per million (ppm).
That also meant that I needed to get a way to test the SO2. I bought a Titrets kit that measures the free SO2 in a sample. I had read about this and apparently there are far more accurate tests out there and this isn’t ideal for red wines (as I’d discover why later). But, it was the least expensive and promised to be easy to use, so I got it.
Back on July 28, I kicked off a test of three different types of yeast. I inoculated some Welch’s grape juice with K1 V1116, EC1118, and D-47. The K1 and EC got off to a quick, foamy start, but were mostly done after a week, and completely done after two. The D-47 was slower to get started and is still going. I didn’t want the the first two hanging out there without active CO2 production going on for too long, so with Tressa’s help, I measured and extracted them.
I moved them up to the kitchen counter and used my deconstructed auto-siphon to old-school-siphon them out into a wine thief, where I measured the specific gravity. Both were exactly at 1.000. So, fermentation was pretty complete. The Welch’s started out at about 1.098, so I was looking at about 13% alcohol there.