A neighbor told us to help ourselves to their remaining grapes, so we went and harvested about 750 lbs of Merlot and 500 of Zin and crushed/destemmed on Sunday with Metabisulfite added at 1/4 tsp per gallon of must.
We weren’t expecting to have these, so we didn’t have yeast at hand and had to go fetch today along with Pectin and Go ferm etc, which meant leaving the must in the T bins for a day. (cool weather but not chilled)
About 30 hrs after destem:
the Merlot was 24 Brix, 3.98 pH and TA of 9g/l, at ambient (67F) with a nice fresh scent
Zin was 16 Brix, 3.2 pH and TA of 9 and running 8 degrees over ambient (75F) with a yeasty smell. (Zinfandel had definite signs of mold on the vines which we tried to screen out, but clearly there was some in the crush. )
Based on the pH of the Merlot, I am assuming we have some level of nutrient buffering, (had 6 1/2 in of rain 2 weeks back) and that the subsequent growth has played with the acid balances.
The Zinfandel seems to be off and fermenting, in spite of the bisufite added yesterday, we may have to dump it at the end, but will play with it for the experience.
We pitched DYW 70A tonight and will see where it goes, expecting to add Fermaid tomorrow to the Merlot (probably could do for the Zin tonight)
Any suggestions on remedial treatments ? I don’t really want to add more acid to the Merlot with the TA at 9, but am not sure how if the pH will settle down.
Since nobody else seems to be around, I guess I will bite.
Are you sure about the TA on the Merlot? I know numbers like that are possible, but just want you to be sure. I know adding acid before ferm is the norm, but adding after is not out of the question, especially if it will be a while before the wine is consumed. When the fermentation is finished, you can taste and see if you think it needs some. Check the numbers again.
As for the Zin, it is probably too late, but at brix that low I probably would have just pressed it off and tried to make a rose out of it.
You can always add Lysozyme or a tannin like VR Supra if you are worried about bacterial issues.
I agree with Linda, a ph of.98 and 9g/l TA seems unlikely, unless the fruit came from an extremely thick canopy, and then still…? Adding acid later is not a problem at all. Just add it in miniscule amounts over a few additions until you are pleased with the balance. It will integrate just fine. Just don’t over do it.
You will need to check your So2 levels, as it takes quite a bit in that ph range, to get enough free(active) SO2.
Lysozyme is an extremely effective(especially with lactobacillus) alternative to high So2 adds. I would consider that seriously.
How can Zin be at 16 Brix, this late in the year, second crop?
The Brix was measured after 30 hrs maceration, since the fruit was rather variable, I wanted to get an average.
As noted, the temp was up and it was already fermenting, so I don’t know what the average starting sugar was
pre-fermentation. Even though we added about 50 ppm based on estimated volume, it was clearly not enough to stop the intrinisic yeasts.