Scarlet Smith wrote:If it rots rather than pickles you may not be using enough salt. We are in the tropics in a woefully uninsulated house that gets super hot. I do only leave it on the bench for 3-7 days, until the little bubbles appear then put it in the fridge. Leaving it out longer in the humidity is asking for rotten ferments.
This seems to make sense, but my research indicates otherwise.
The optimum temperature for sauerkraut fermentation is around 21ºC. A variation of just a few degrees from this temperature alters the activity of the microbial process and affects the quality of the final product. Therefore, temperature control is one of the most important factors in the sauerkraut process. A temperature of 18º to 22º C is most desirable for initiating fermentation since this is the optimum temperature range for the growth and metabolism of L. mesenteroides. Temperatures above 22ºC favour the growth of Lactobacillus species.
And the Lactobacillus species are less salt tolerant than L. mesenteroides, meanwhile the bacterias that cause spoilage can tolerate salt concentrations up to 7%. Its the acid produced by the anaerobic cultures that preserves the food, not the salt. (Unless you're using bucket loads of salt (above 7%), which will simply preserve the food by preventing both desired and undesired bacteria without any fermentation).
So. . . . . since lactic acid will be favored above 22 degrees it makes sense to use a little less salt. It might also help to use a starter culture to achieve an acidic environment quickly, or to add some acidic fruit like a green apple. The end product should be safe and healthy to eat but would have a different taste to krout that has been initiated at 'fall' temperatures, given the different range of microbes involved.
I live in a tropical climate and we have plenty of cabbages here. Both the European and Asian kinds. I think they're grown up in the hills.