Personally I wouldn’t re use jalapeño pickling liquid to make more jalapeño pickles, instead you can use it to season a pot of beans for example or a braise.
If you want to make lacto-fermentred pickles, start from scratch. The simmered in vinegar and sometimes sugar kind, it’s probably OK to strain the brine and top it up.
Who knows, maybe one day I’ll explore the world of lacto-fermentation. I looked it up. Interesting history. I’ve got all this vinegar. I want to make use of it. Can you offer any suggestions?
You mention “simmer”, so do we go about that? Any special steps? I don’t understand what you mean by “it’s probably OK to strain the brine and top it up”.
The picante / spice is going to be amped up on the second use & it will be out of balance. It’s okay to re use pickle liquid once so if you want to take that and pickle carrots, cucumbers ect it should be fine but personally I would not use it to make more pickled jalapeños. you should cut them in half or cut a slit into them so the pickling liquid gets inside