Lavorgna,
Hi, how long has it been since fermentation completed? Although MLB is usually inoculated before racking, therefore on the Lees, it will be fine without it, it is just another source of nutrients, if you add a Malolactic nutrient such as Opti-Malo, you will be fine.
lawrstin had a good point regarding meta, have you stabilized your wine yet? As far as SO2 and ABV levels, it really depends on the MLB that you intend on using, I would recommend Bacchus for a 5-6 gallon batch, for anything larger, I'd go with VP 41, by the time you purchase a few packets of (Lalvin) Bacchus, you could get VP 41.
There is a great deal of difference between wine that has been put through MLF and a wine that hasn't, obviously we are talking about reds, there are only a few whites that are normally put through MLF.
The most obvious differences will be such as taste, mouth feel, smoothness, aromas to name a few. The biggest issue with not putting wine through MLF is the possibility of spontaneous Malolactic fermentation from wild MLB strains, the results can be as dangerous as bottle bursting, negative characteristics associated with that particular strain of wild bacteria.
To make matters worse, if a spontaneous, but undesirable, strain of Malolactic bacteria becomes implanted in the winery, then all subsequent wine made in that winery, commercial or home winery, may be in danger of exhibiting the negative characteristics associated with that particular strain of bacteria.
The key is to use a reliable strain of MLB, I use either lalvin VP41 or MBR 31.
The MLB available to us today have been screened for tolerance to the wine components that can inhibit or prevent their growth such as PH, TA, SO2, Alcohol and temperature tolerances.
VP 41 will perform well at a pH above 3.2 and a total SO2 level of 50-60 ppm, if you added meta, the normal 1/4 tsp per 5-6 gals of wine averages out to be approx. 50 ppm, take into consideration how sulfites react with various various chemical compounds and solids naturally present in our wines, the amount of free sulfite remaining in the wine after we make an addition often falls short of our calculated goal, I think that you will be fine, it also does well In temperatures below 16ºC(61ºF) it is a slow starter but can complete fermentation.
Nutritional requirements of MLB strains were researched, as was the compatibility with various yeast strains used to produce the wine, with this data we can ensure reliable and complete MLF.
MLF is very easy, I highly recommend purchasing Acti-ML, a MLB hydrating nutrient, and Opti-Malo Plus, a MLB nutrient.
I hope this helps, if you have any other questions, don't hesitate to ask.
