MALIC ACID Smell in Einkorn Starter

Following Carla Bartolucci's directions for basic einkorn sourdough starter, I developed a couple of starters over the last few months. Only difference being, I used whole wheat einkorn instead of all purpose. One of the starters got a couple pale spots last week which were "veiny" in texture. Probably just the yeast protecting itself from being underfed. I was a day late in feeding it.

This week the same starter has developed a distinct smell of malic acid ("apple" flavor used in sweets). Also the surface has grown darker (this is normal), with an even layer of pale spots a little larger than pinholes all over (not normal). And on the tips of some of the "ridges" in the surface (my starter is usually pretty thick so its surface retains its texture), there are about seven pure white spots the size of a pinhole.

I've heard the sweet, fruity smell is sought-after by some! May come from small amounts of malic acid present in the flour. The white dots, however, concern me. Could it be an unwanted mold?

The other starter is looking/smelling normal. A not-too-sour, pleasantly cheddar-like smell.

Anyone else had their starter smell go through a pear or apple phase? Anyone wanted this? I've heard of people adding apple juice to their starters intentionally, or ACV. Am I basically achieving the same effect but without added juice?