Higher So2 w/o any additions

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Oct 25, 2016
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S. Jersey/Philadelphia area
Finally got around racking, sulphiting, and barreling a Malbec made from Chilean grapes from this past May.
Free So2 at crush was about 12ppm.
I dosed up to 25ppm initially.
Fermentation went well. MLf finished completely. I haven’t racked or added anything at all since the initial rack off gross lees until now.
About 5 months since I dosed to 25ppm pre AF.
With a ph of 3.2 the chart says 13-21ppm needed.
Free So2 levels in multiple vessels read ........ ~30ppm ! I was expecting 0ppm
I may have given a Kmeta spritz or 2 to the carboys over that time. And AF produces some. That’s all I can think of. But 30ppm after 5 months? I use the titrets to test. Not
100%. But accurate enough to know the ballpark.
I dosed another 20 to be safe- splash racked off the light lees (Had some crystals in there) and filled the barrel.
For those who check So2 levels-
Do you find that your free ppms don’t drop as much as previously thought?
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Racking with AI1 it its also worth mentioning it was still loaded with co2. That help retain So2?
Ive been leaning towards less racking recently. Between the existing So2 level, the high acid, the co2, and topped up— this wine had more than enough protection.
One nice byproduct is the lees becomes very compact and less likely to transfer any over.
Last fall’s wines sat for a length of time I’m almost too embarrassed to admit. 6-7 months maybe. 70ppm in November. 40ppm in June IRRC. The lees solidified completely. Had to break it up to remove.
All this meant to say that if I had simply dosed 1/4 tsp per 6 gal every 3 months my So2 would be through the roof!
It doesn't really make sense to have free SO2 after AF and ML. I've never used the Chilean grapes so I can't comment on what effect if any. I usually add a low sulfite dose pre AF, 30 to 35ppm, and by the time ML is complete, I have to make usually two sulfite additions to hit my target. If I'm shooting for 30ppm free, I usually add 40ppm, two weeks later I'll test and find I need another 20 to actually get to 30ppm free.

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