Soda ash

[ninagrey]

I've been making soap for years. Had the occasional soda ash. However my recent Batch has been sitting 3 months, the Top zaps. Only the tops. I havent yet steamed them, I cut the top off and its fine.
There are no signs of it being lye heavy, I check my scales with a calibration weight before I use wvwrytime.
Any idea why the soda ash is causing a zap?

 

[Ekuzo]

Soda ash isn't supposed to zap. Maybe you got some undissolved lye that ended at the top of your batter when you poured?