What is Kahm Yeast?
Kahm yeast is a general term for various wild yeasts that can colonize the surface of fermented vegetables. It appears as a white, wrinkly, or sometimes powdery film floating on top of your brine.
Unlike mold, which is fuzzy and often colored, kahm yeast is flat against the liquid surface. It's not dangerous but can impart off-flavors if allowed to persist.
Identifying Kahm Yeast
Appearance characteristics:
- •Flat, thin film on surface
- •White to cream colored
- •Wrinkled or bubbly texture
- •May have a slightly powdery look
- •Lies flat on the brine (not fuzzy or raised)
Smell:
- •Slightly yeasty
- •May smell bread-like
- •Not putrid or offensive
Is Kahm Yeast Safe?
Yes, kahm yeast is safe. Many fermenters simply skim it off and continue their ferment. However, if left unchecked, it can:
- •Impart yeasty or off-flavors
- •Potentially lead to other issues if it grows extensively
- •Make your ferment less visually appealing
How to Remove Kahm Yeast
- •Skim the surface with a clean spoon, removing as much of the film as possible
- •Wipe the jar rim above the brine line
- •Check your weights and ensure vegetables are submerged
- •Add fresh brine if levels are low
Prevention Strategies
- •Keep all vegetables submerged below brine
- •Use fermentation weights or plates
- •Maintain proper salt levels (2-3%)
- •Use airlocks to limit oxygen exposure
- •Ferment in cooler temperatures
- •Minimize opening the jar