What is hovering above my GF Porter yeast cake?

[Podzol]

Hello!
This is my yeast cake on a 17 day primary fermenting batch of a Gluten Free Porter.
I used Nottingham yeast, the grain bill is predominantly Rice malt, but has some oats, millet malt, and buckwheat malts. I used Ondea Pro and Ceramix Flex enzymes with Irish moss and Diammonium phosphate as nutrient. I did a rising mash with rests at 100, 125, 145, 158, and 175F.
The active fermentation was fast and furious churning with a visible boil the first day then quit. My hydrometer is broken, so I don't have readings. I figure I'd just give it plenty of time this round.
Anyone see a floating layer like this? I'm thinking maybe the oat buckwheat 'slime' didn't digest all the way in the beta-Glucan rest and settled out as a transparent layer.
The beer does not appear infected with a pellicle, just some tawny brown yeast rafts floating right below the surface, but went through a skanky smelling stage as nose from the air stop, a week after the vigorous fermentation

 

[hotbeer]

As the stuff suspended in your beer starts to settle out more you will have a layer of very clean beer. If you wait long enough it'll all be very clean.

And since you broke your hydrometer, if you wait till all the beer is clean then you probably reached it's FG quite a bit before that time. If it hasn't already gotten there.

But I might be misunderstanding what you are referring to. The picture looks similar to many batches I've done.

Changing smells, sometimes unpleasant coming from the fermenter in the early part of fermentation are not a worry. Nothing else to be concerned about based on the picture, IMO.

 

[Podzol]

Thanks @hotbeer. This my first original recipe- I even malted some of the ingredients myself, so I'm a bit of a nervous nellie over it. If you haven't tried malting yourself, I'd recommend doing it at least once. It was amazing to experience all the good smells emerge from germination, kilning and roasting. I malted the millet and barley. I did an enzyme malt on minute rice to make some GF crystal, and that turned out awesome. I have a pale ale in the works that features that with a more transparent grain bill.

 

[IslandLizard]

[EDIT] Trub, being the layer settled out on the bottom of your fermenter consists of solids and yeast, and can take on many forms.
In the picture I see sand-like granules (probably from grain) mixed in with a whitish substance, most likely yeast.

What's most important, you've got yummy looking, clear dark beer on top. I'd say it's probably done it being on the 17th day.

Although a hydrometer is the best tool for measuring gravity after fermentation, you could instead use a refractometer, if you have one.

 

[Podzol]

Thanks! I'll look up refractometer, and maybe put one on my list. I'm planning on bottling this on day 21 (no secondary since it's clearing nicely). The stanky smell that has has mostly dissipated has me wanting to take this one sloooowly and give the yeasties plenty of time to mop up.

 

[bellhp]

Congratulations , I hope it turns out the way you expected .That was a very ambitious batch of beer

 

[IslandLizard]

I'll look up refractometer, and maybe put one on my list.

They're most useful for taking quick gravity readings, often used during brewing.

Once alcohol is created a refractometer reading will be skewed, reading too high, and needs to be corrected with a calculator (like this one).

But it would be best to have a hydrometer for taking final readings. Just handle it more carefully, they're very delicate. Never lie it on a smooth countertop or it will roll off. Also make sure the bottom of the storage tube is solid, or if just a plug, tape it down.

You can pick up a refractometer (for sugar, wort) for around $20.

 

[Podzol]

thanks! I definitely pick one up!

 

[Podzol]

That was a very ambitious batch of beer

Yeah, a lot of this gluten free brewing belongs in a biochem class. I have learned a lot! Thanks!