I am a new meadmaker who has made a few batches, including some melomels with peaches and strawberries. After thorough primary and secondary fermentation with clear mead, I usually add potassium sorbate 1/2 tsp/gallon to make sure fermentation is stopped, wait a few days, rack, then bottle. Everything looks clear at bottling, but some of my batches get a fine sediment; others get a darker sediment that suggests the mead has spoiled. I use sanitary techniques and don't know how to prevent this from happening. Any ideas? Thanks!