Brown foam at top of carboy during malolactic fermentation

[ChrisL]

Hi Everyone,

I'm making 3 gallons of malbec from frozen grape must, which I fermented, pressed, and racked off the gross lees into a carboy two weeks ago. After racking I introduced malolactic bacteria and added about an ounce of oak cubes. Today, I noticed that there is a small bit of tan/brown foam that's accumulated in the neck of the carboy, as in this picture I took. I'm wondering if anyone has ever encountered this before/if this is normal? Could it be coming from the CO2 pushing up some of the lees, bacteria, or particles from the oak cubes or is it instead some sort of defect?

Sincerely,
Chris

 

[ibglowin]

If you added oak its just some of the oak powder/dust that came off the cubes. Happens all the time. It will dissipate/sink overt time.

 

[Johny99]

I agree with ibglowin. Co2 often brings various sediments up. If it gets too thick or unsightly you can pull some off with a pipet or straw.

 

[ChrisL]

Great-- thank you both for your responses!