Foam in Wine

[brew hoperator]

I am not a wine maker but my FIL is and he had an issue with a batch that he has never had before. I told him that I would ask on this forum to see if i could get some information for him.

He said after they bottled the wine and aged it for a few months, they poured a bottle and it had a lot a foam. He described it as being like foam you see in Champange/Sparkling wine, but they did not make a sparkling wine kit.

Does anyone have an idea on the cause? Could their bottles have been improperly cleaned? Thanks in advance.

 

[EoinMag]

Wines have a light sparkle unless you either degas with a whip or allow them to stand under airlock in secondary for long enough that they completely off-gas naturally. I suspect they did neither and ended up with a light sparkle.

 

[ChshreCat]

+1 either it wasn't degassed and had too much CO2, or they bottled too soon and there was a little fermentation in the bottle. If it's the latter, I'd worry about bottles breaking or corks being forced out by the pressure if it is still fermenting. If I were him, I'd carefully uncork another one and see if it's the same way. If so, maybe he could uncork them all and recork them to relieve some of the pressure?

 

[CandleWineProject]

How does it taste?

Could MLF have happened?

 

[brew hoperator]

He said it tasted fine.

What is MLF?

 

[ChshreCat]

malolactic fermentation