Question about tiny bubbles in secondary...

[Angry Chemist]

I'm a newbie to home brewing. I have 2-5 gal extract brews and 2-1 gal extract brews under my belt; so, I still have a lot to learn. My third extract kit is a 5 gal milk stout and it's in the last stages of secondary - I plan to bottle tomorrow. The middle of last week, 8 days ago, I added vodka soaked cocoa nibs, cinnamon stick, and a vanilla bean to the secondary. I soaked them in 12 ounces of vodka for about 4 days and then dumped the whole lot in. That amount of vodka should raise my ABV by almost 1% and bring my final ABV to around 5.2%. I noticed a few days ago that there was something floating on the surface. I immediately thought they were fuzzies and that I had an infection. However, when I shook the carboy a little the clusters separated into what appears to be fine lacing. Then, most of them went away. They did come back a couple days later. What's going on in there? I'm wondering, were there some fermentables in the cocoa nib concoction and I'm seeing tiny CO2 bubbles from that? Or something else altogether?

 

[J A]

Same thing happens with dry-hopping. There may be some increased yeast activity resulting from the small amount of sugars in the vegetable matter. If you have a yeast that tends to get sluggish, the action of dumping something in may be enough to rouse some new activity. Or it's just nucleation from throwing stuff into a liquid with CO2 in solution. Either way a small amount of bubbling shouldn't indicate anything particularly troubling.
More importantly is that if you're going to bottle you should have checked the gravity a couple of times over 2-3 days to be sure that it stabilized and is at final gravity. That's the only way you can be sure it's actually ready.

 

[Angry Chemist]

Same thing happens with dry-hopping. There may be some increased yeast activity resulting from the small amount of sugars in the vegetable matter. If you have a yeast that tends to get sluggish, the action of dumping something in may be enough to rouse some new activity. Or it's just nucleation from throwing stuff into a liquid with CO2 in solution. Either way a small amount of bubbling shouldn't indicate anything particularly troubling.
More importantly is that if you're going to bottle you should have checked the gravity a couple of times over 2-3 days to be sure that it stabilized and is at final gravity. That's the only way you can be sure it's actually ready.

Thanks for the insight. I did check my gravity after two weeks in primary, and it measured in the range for what the kit instructions stated. Tomorrow will be nearly 5 weeks total, 3 in secondary. I will check final gravity at bottling, to also check and see if my ABV increase from the vodka was as effective as predicted (V1C1=V2C2). I'm not a fan of opening my carboy or using a spigot anymore than is absolutely necessary. As a chemist, I'm a bit anal when it comes to sanitation. If it's not finished after 5 weeks, then I probably don't have the patience to continue, to be honest. What have you found the most sanitary way to take a gravity reading to be? I have both a thief and bubblers with spigots.

 

[GFHomebrew]

After 5 weeks if it's not done I'll be amazed . I use phosphoric acid sanitizer to sanitize my spigot on my fermentor before drawing off a sample then I'll give it another spray when done just in case any nasty bacteria congregates around my tap.

 

[Mark D Pirate]

Once its fermented out the alcohol and low pH will limit infection to a degree , hops are also a natural preservative with anti bacterial properties .

Aceto / lacto infections can happen and taste bloody awful !

 

[Angry Chemist]

Once its fermented out the alcohol and low pH will limit infection to a degree , hops are also a natural preservative with anti bacterial properties .

Aceto / lacto infections can happen and taste bloody awful !

Other than tasting terrible, what are the indications of a lacto infection?

 

[Mark D Pirate]

White film on the top , looks like coconut flakes or dandruff .

It can be done intentionally for some styles but very hard to accidentally make a decent sour