The following is from Low Carb Friends
It is easy to lacto-ferment veggies and suitable fruits. Wash thoroughly, cut into slices or small pieces, and pack tightly into a jar or crock. If using quart jars, add 4 tbs whey, 1 tbs natural sea salt (not iodized), spices, and water—filtered or distilled (not plain tap water). Water should to be added to within an inch of the top. Jars need to be sealed tightly...just a canning lid and ring…but it doesn’t have to be put in a canner or water bath...just tightly sealed. Set in a warm place for 2-3 days, then store in a dark, cool place. It’s not uncommon for the ‘brine’ to bubble and hiss as the fermentation process continues.
The food needs to be kept submerged in the liquid. Foods tend to float up, and the top part is no longer in the brine, which is not an ideal situation. I haven’t figured out a good way when using quart jars to prevent this from happening. I guess that’s why crocks are used…the opening is large enough to put some sort of weight on top of the food to keep it below liquid level. And, there are specially designed crocks now that have lids that create an airtight seal using water. The one drawback with this crock design, the water needs to be carefully watched so it can be replenished to maintain the airtight seal.
Vegetables will last a long time…a year and more. Fruit should be eaten within a few months, because they can become ‘hard’ fairly easily. Lacto-fermentating of fruit juice can easily cause it to become vinegar.