I am trying to make an Italian giardiniera, Chopped veggies in a brine of water, sea salt and raw apple cider vinegar. (using 5gal pickle buckets) I have a film that builds on my brine even when a dinner plate holds the veggies under the brine. Can i trust skimming most of the layer off and putting the unheated mix in jars? Also the brine is expensive with $17/gal vinegar. Can i use some or all of the old brine in the next batch like an inoculation? Im using 5gal buckets, is there any off-gas or toxic problems with the plastic?