Riesling wine smells great. Run smells ammonia

[Graw]

Made 12 gallons of Riesling wine. Turned out great smells and looks normal. Running it thru the pot still w thumper right now and it smells like ammonia. I’m on the 3rd quart jar and smell still there. It’s coming out at 142 proof which is right at what my still produces.
What could be the cause of the smell? Is this batch ruined? It is perfectly clear.