If you find a cluster of questionable white spots on your kimchi, there’s a good chance that they’re yeast, not mold. In the case of yeast, you won’t have to discard your kimchi.
Moldy kimchi is relatively rare because, as a fermented food, its acidity prevents spoilage. As long as the cabbage remains submerged in the brine, mold formation is unlikely.
To check, closely examine the white spots. If they aren’t plain white, have other colors present, and are fuzzy, it may be mold and you will have to toss the kimchi in the trash.
Yeast; however, is preventable. Simply store your kimchi in a cool place, use clean utensils while digging into its container, and keep it tightly covered to limit air exposure.
If the kimchi is still early in the fermentation process, and there’s little air at the top of the container, you may need to periodically open it to release excess air.
It’s advisable to remove the white yeast, and clean and cook your kimchi before consuming it, primarily to maintain its freshness rather than due to any health risks.
Although unappetizing, the yeast is harmless — particularly in small amounts — supported by studies indicating no toxins or negative health effects associated with its consumption.