posted 3 years ago
When I prepare beetroot for pickling, I steam them whole in the pressure cooker and the skin just rubs off. It sounds as those the beets that you purchased may not have been pickled, the sweetness would have been from the natural sugars in the beetroot.
If they were slightly acidic, they may have been lacto fermented but it is unlikely that any pebbles would have remained embedded in them? What appeared to be dirt may have been blemishes in the skin.
You could try pickling some whole beetroot yourself in a lighty sweetened vinegar, just dilute the vinegar so it's not so sharp - I'd start with 20% sugar to volume of liquid, boil with whatever whole spices you like (I use black peppercorns, garlic, ginger & chilis) and taste it when the vinegar has cooled.
Leave for at least six weeks for the vinegar to permeate the beets. We always slice our beetroot so they stay in the jar but if they are whole beets, the seller may have decided to drain them and sell them loose.
Keep us posted on how you get on.