Possible infection in secondary storage, need advice

[drastic_quench]

I've got a show mead in secondary (6.5 gallon carboy w/ 3 piece airlock, in dark/temp controlled area) that will be 6 months aged come the end of June. The abv is just shy of 11%. No off smells detectable.

Within the last week, the surface took on a very faint white wispy color, and multiple rings of white have formed. The rings range from pea-sized to smaller. See the attached picture.

http://i41.tinypic.com/2gx0gph.jpg

QUESTIONS:
Is this mold or something else?

Will it still be safe to drink (if it tastes poor, never mind)?

Should I attempt to re-rack the mead?

I followed all cleaning and sanitation practices with reliable chemicals like StarSan, and kept the airlock at level. Why would this crop up in a mead that's been finished for four months???

Thanks.

 

[Medsen Fey]

Can you provide the recipe details please?

 

[drastic_quench]

Sure, why not.

15lbs honey
spring water to five gallon line
Lalvin D-47 yeast x2
standard staggered nutrient additions

This is my first mead, gents. I'd appreciate some insight as to what the deal is here.

 

[Medsen Fey]

A few more details please. What was your starting gravity and final gravity? how many times have you racked? how much headspace do you have? Do you know the pH?

I can't tell too much from the picture as it isn't very clear, but I'm suspicious of a spoilage organism. I think I would rack underneath it and sulfite it well and make sure it is in a container without exposure to air.

 

[drastic_quench]

don't know ph
don't have my grav notes handy, but I did the math with the figures, and it worked out to 10.5 abv
maybe a gallon of headspace
racked once from ale pale to carboy

 

[Medsen Fey]

That's way too much headspace unless you keep it flushed with some inert gas or CO2.

I'd rack,sulfite and top up ASAP.

 

[afdoty]

That's way too much headspace unless you keep it flushed with some inert gas or CO2.

I rack,sulfite and top up ASAP.

Rack to maybe a 5 gallon carboy? Leave the floaters on the top surface in the old carboy. Make sure to FILL the new carboy right to the top, with just enough space for you airlock.

 

[drastic_quench]

That's way too much headspace unless you keep it flushed with some inert gas or CO2.

I rack,sulfite and top up ASAP.

It's not oxidized because I racked it before it was completely done fermenting. It naturally produced a blanket of CO2 over the surface.

 

[Medsen Fey]

Most stoppers/bungs are not going to keep oxygen out indefinitely, and most especially not if you take it off to take samples or make additions every once in a while (oak, acids, fining agents, or whatever). If you've ever removed the stopper, when that occurred, oxygen got into the headspace.

While CO2 (or Argon) happen to be heavier than air, they will not prevent oxygen from diffusing from the high concentration area (near the opening) to the low concentration area (near and in the mead) as the molecules bounce around in the enclosed space. To put another spin on it, ask yourself why all the Argon and CO2 in the atmosphere doesn't sink down to the bottom and choke us all?

It is somewhat of an urban legend that a blanket of heavier gas will prevent oxygen from getting to the mead. That is why commercial operations using inert gases don't just give a little puff into their tanks and leave it at that. They will flush the volume of headspace with 4-5X the volume of inert gas to flush the oxygen out, and use oxygen meters to measure the oxygen present to make sure it is below thresholds for storage.

Whenever I open one of my storage containers, I flush it with large amounts of gas, even then knowing I'm probably not getting all the oxygen out (but it doesn't keep me up at night).

Traditional meads tend to be less prone to oxidation than grape wines, but they certainly can be oxidized (done that). In your case the mead may not be oxidized, but if you've got stuff growing in rings on the surface, you have too much oxygen exposure.

Again, I would rack, sulfite and top up.

Medsen