question about preserved lemons

Preserved lemons, according to Paula Wolfert, often develop a white lacy substance in the process of curing that is harmless. It appears in the liquid. My preserved lemons have often developed this lacy substance and I'm still here to tell the tale. If that is what you are seeing, you don't need to worry.

The white fuzz in preserved lemons is mold and it is harmless:

https://www.npr.org/2013/04/08/176577903/preserved-lemons-older-wiser-and-full-of-flavor

Let's take this moment to dispel the ongoing myth that mold is always bad.

It's not.

White mold in many other fermented products are fine (sauerkraut is one; the green mold though is bad in this particular preparation).

Another moldy product? Well, cheese. I'm sure most readers here have had cheese before.

In addition to the cheesemaking countries, the Japanese are experts at using mold to develop some renown items such as sake, miso, and soy sauce, all from the fungus Aspergillus oryzae (a.k.a. "koji").

Mold is the original source of penicillin.

So let's just put an end to this sweeping "mold is bad" generalization.

Hm...what is the white stuff? Is it fuzzy (mold, which would be bad), crystallized (salt that crusted near the top, which would be ok)? The preserved lemons I've made were supposed to last a few months max, though we used them within a few weeks. Other recipes vary on how long the lemons are supposed to be kept. Are the lemons submerged and well covered in liquid, and/or do you have an oil layer on top to help keep your lemons covered?