adjusting the So2 levels is not going to be practical really.
what yeast are you using?
i think the tartaric acid addition instead of blend is fine myself.
1/2 tsp of k-meta is roughly 100ppm depending on pH, about 2x the typical dose.
the MAIN reason to add k-meta at all before adding cultured yeast is to temporarily shock wild yeasts and allow cultured yeasts to take over. all yeast is succeptible to SO2 levels but cultured usually less so than wild yeasts.
after introducing that small roughly 50ppm dose (again, depending on pH) we usually wait (cold soak) 24-48 hours before pitching our cultured yeast. this allows some of that so2 to become bound and create a better environment for our cultured yeast.
typically with fresh juice or grapes, next in the process is to rehydrate the yeast culture in warm water according to instructions or alongside a yeast energizer/rehydration medium like Go-Ferm. this provides essential nutrients to yeast which help them build strong cellular walls and such to get off to a better start in the must or juice - think of it like pasta supper before a big race.
after the yeast has rehydrated for 20min or so, (again,read instructions for your yeast) it is pitched and temps are kept in optimal range for that yeast, typically a bit warmer than room temp... when brix has dropped 1/3, a yeat nutrient is often added to the must or juice, something like fermaid-K (like a power bar during the race)... then the wine is fermented to dry or nearly dry before pressing (in the case of grapes) and then racked into carboys for further fermentation... MLF, which is typically VERY sulfite intolerant, can be pitched when fermentation is around 5 brix or according to instructions. i pitch on the skins at 5 brix and i think the skins help provide some nutrients to ensure the ML bacteria get off to a good start. then i press at dry.
kept in moderate temps under airlock with minimal headspace, wine can go through ML fermentation in a matter of weeks to months. i do not apply any additional k-meta until ML fermentation is complete. at that point i rack, test sulfite levels and apply the necessary dosage to achieve 50ppm for the pH i have. and so on into long term aging, oak spiraling, etc.
an excellent book is From Vines to Wine. great resource for testing methods and step by step in juice and fresh grape winemaking. clear examples and good explanation of the calculations of proper additions and so on.
in your instance here and now, we need to know what yeast you are using, if you've rehydrated the yeast according to instructions, the rate of application for nutrient or energizer and your pH levels and what brought you to the decision to adjust acid in the first place. if your pH was very high for the juice in the beginning, the extra k-meta may have had less of an impact than you would think. the proper sulfite dosage is very tied to pH, and there's also a correlation between TA and pH but it is not a linear correlation. adding tartaric can lower pH and is sometimes used to do just that in high pH wines... but lower pH can impact MLF negatively, while improving color fixing and biological stability... it can get pretty crazy when you start making adjustments as each has an effect on the other and can create a domino effect of despair! lol.
lastly, visual indicators of fermentation are fairly unreliable and comparing one varietal fermentation to another different varietal fermentation is apples to oranges. two pails of the exact same juice can have different fermentations... so concentrate on what it is doing by the numbers, not by comparison to anything else. if SO2 was too high, it could take longer for the ferment to take hold. monitor your brix/SG levels daily for confirmation of forward progress. keep a log of that. a refractometer is especially handy for daily monitoring because it takes such a small sample and is easy to use in that way. if fermentation as indicated by SG dropping or obvious airlock activity or surface foaming is not happening by sunday, then run another round of tests to see where your pH is, your sulfite levels and your TA - report that back here and we can make a better assessment of next steps. you might need to go to a superyeast with high sulfite tolerances and wide pH range like EC1118 or you might need to go the route of preparing a yeast starter and creating an active ferment on a small scale and slowly introducing your juice into that until 50% of your juice is actively fermenting. but we can deal with those details later if this ferment does not take off.
