Ok one very slight difference in technique that I use. I'd recommend not waiting more than 48 hours after you have hit your must with the K Meta to add the K Sorbate. Reason is your free SO2 will fade after the initial dosage and will lose it's effectiveness as an antimicrobial and antioxidant as time passes. A couple of days is not a dealbreaker, but, the pH of the mead is an important factor. I've gone into this in another post on the general forums.
My suggestion is based on mead not being a static animal, it is constantly evolving and there are shifting levels of acid, sugar, alcohol and other factors that will influence the efficacy of your sulfite and sorbate. pH is the heaviest deciding factor, and as Wayne mentioned if you get the dreaded Geranium smell then you're done. The bacteria reduce sorbic acid to sorbic alcohol, which in the presence of low alcohol and low pH, gives a rearrangement to 2-ethoxyhexa-3,5-diene the latter having a geranium-like aroma (Crowell and Guymon 1975)
However, if you are diligent about blanketing your vessel with CO2, Nitrogen or Argon you'll be fine. Lactobacillus are Gram+, microaerophilic bacteria (the love small amounts of oxygen) they can be everything from rods all the way to coccobacilli. They need oxygen in order to work their magic to a point of where you'll pick it up in sensory analysis.
Lactobacillus, along with Oenococcus and Pediococcus, are classified as Lactic Acid Bacteria (LAB). Another strike against LAB are that they have complex nutritional requirements. In addition to carbohydrates, they require amino acids, nucleic acids, vitamins and fatty acids. They also metabolize hexose. Lactobacillus are generally catorigized as homofermenters, and heterofermenters. Homofermentive lactobacilli will convert glucose to lactic acid without the production of CO2. Heterofermentive lactobacilli are more vigorous and will metabolize hexoses into a "heterogeneous" amount of compounds, like lactic acid, CO2, ethanol and acetate. The occurrence of Lactobacillus in wine is highly pH- and ethanol-dependent. In high-pH wines greater than 3.5, Lactobacillus will dominate, but at lower pH values, Oenococcus oeni will dominate like a cheap Hollywood dominatrix (for those of you who's eyes were rolling back in your heads by this point, see, I know I run-off sometimes). Variances in ethanol tolerance among Lactobacillus species is common. For example, L. plantarum ceases growth at 5 to 6 percent ethanol, whereas L. casei and L. brevis are very alcohol-tolerant, and are the ones used to induce malolactic fermentation (MLF).
OK this also goes for Acetobacter sp. If I remember right I've posted on that a couple years back as well. Keep your pH down, your O2 down and you won't have problems.
Cheers,
Oskaar
