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Bret

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My post-bottling recheck of FSO2 (free SO2) is lower than recommended, where recommended level is 33, and actual level is 24. Should I open the bottles, add more K-meta (potassium metabisulfite), and rebottle?

Wine is 5 gallons of Shiraz made from Australian juice. Fermented to dry. Treated with oak, underwent MLF (malolactic fermentation) cold stabilization, bentonite, Tan'Cor added, K-meta maintained at recommended levels per pH chart (except during MLF) and using FermCalc phone app, degassed with Mix-Stir on drill in bottling bucket.

Just prior to bottling, pH=3.59, FSO2=20 ppm (mg/L), TA=0.9 g/L (9%), and from starting and finished specific gravities, estimated EtOH is 14.3 % ABV. The wine was clear and looked, smelled and tasted good.

Per my wall graph the recommended FSO2 level for pH was 33, and to get from 20 to 33 needed 0.43 g of K-meta. To cover SO2 loss during bottling, I figured an extra 35% with 0.15 g. 0.43+0.15=0.58. I weighed out 0.58 g of K-meta and mixed in well.

I then bottled directly from the spout, the first drawn was a one gallon jug to probably use for a blend, and the rest into 20 full bottles, plus a partial 21st clear bottle about 90% full, and that last bottle was poured through a funnel and was kind of foamy. OF NOTE: The last, partial bottle has a few white spots floating on the top, suspicious for infection, which I have seen before in carboy and which resolved after using a paper towel to soak them up and adding more K-meta.

Synthetic NomaCorcs were used for the 750 mL bottles, using a corker for each bottle right after each one was filled.

The next day I rechecked FSO2 from the gallon jug and got 24 ppm. I then tested a bottle that was midway through the bottling order and got 28 ppm.

I do not know the aging potential of this batch, but probably 50% of it will be given away, and the rest I will drink over a few years, following it as it progresses to its peak.

I'm willing to empty the batch, add more K-meta and rebottle, but should I? And how much more K-meta should I add if I should do so?

Thanks!

-Bret
 
My post-bottling recheck of FSO2 (free SO2) is lower than recommended, where recommended level is 33, and actual level is 24. Should I open the bottles, add more K-meta (potassium metabisulfite), and rebottle?

Wine is 5 gallons of Shiraz made from Australian juice. Fermented to dry. Treated with oak, underwent MLF (malolactic fermentation) cold stabilization, bentonite, Tan'Cor added, K-meta maintained at recommended levels per pH chart (except during MLF) and using FermCalc phone app, degassed with Mix-Stir on drill in bottling bucket.

Just prior to bottling, pH=3.59, FSO2=20 ppm (mg/L), TA=0.9 g/L (9%), and from starting and finished specific gravities, estimated EtOH is 14.3 % ABV. The wine was clear and looked, smelled and tasted good.

Per my wall graph the recommended FSO2 level for pH was 33, and to get from 20 to 33 needed 0.43 g of K-meta. To cover SO2 loss during bottling, I figured an extra 35% with 0.15 g. 0.43+0.15=0.58. I weighed out 0.58 g of K-meta and mixed in well.

I then bottled directly from the spout, the first drawn was a one gallon jug to probably use for a blend, and the rest into 20 full bottles, plus a partial 21st clear bottle about 90% full, and that last bottle was poured through a funnel and was kind of foamy. OF NOTE: The last, partial bottle has a few white spots floating on the top, suspicious for infection, which I have seen before in carboy and which resolved after using a paper towel to soak them up and adding more K-meta.

Synthetic NomaCorcs were used for the 750 mL bottles, using a corker for each bottle right after each one was filled.

The next day I rechecked FSO2 from the gallon jug and got 24 ppm. I then tested a bottle that was midway through the bottling order and got 28 ppm.

I do not know the aging potential of this batch, but probably 50% of it will be given away, and the rest I will drink over a few years, following it as it progresses to its peak.

I'm willing to empty the batch, add more K-meta and rebottle, but should I? And how much more K-meta should I add if I should do so?

Thanks!

-Bret
24 is fine
 
Free SO2 is very reactive I would expect it to be lower at 24 hours.

Q: will you oxygenate the batch uncorking it and pouring it back into a bucket? ,,, Yes, pouring them out would double the bottle shock.
Q: Do you have other antioxidants in your wine? ,,,, Yes red grape normally is resistant to oxidizers since it contains tannins and other radical acceptors as reversitol.

In the old days great grandpa managed to make vintage red wines with the natural antioxidants, we must be sloppy if we have to rely on free SO2.
 
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