I mixed up a bunch of vds about 3 months ago, I have stepped away for the process for a while and just came back to it last night. I noticed a 1/8" layer of material at the bottle of my jar. I'm having trouble getting it all back into solution. I've tried warm water, stirring, shaking. Is this what is referred to as 'precipitate,' in which case I could use a few grams of tartaric acid to aid in dissolving. Any suggestions?