Yeast cake looking weird to me... (with pictures!)

Hello everyone. Long-time forum lurker, first time poster.

I'm currently looking at a situation I'm unfamiliar with.

Simple Oatmeal stout, third attempt after some earlier setbacks (which we'll not discuss, hehe)

First 24h after pitching, I came home to check on my ale and found that yeast (or something else, but likely yeast) was clumping into small grain-like bits at the top the mixture. Like coarse sand or something. (see photos below) As you'll notice, there's that initial layer of coarse cake-thing, and then the usual foam that you'll find on a fermenting batch.

I'm kind of freaking out, because I haven't seen this before and I'm wondering if it's the sign of a total-failure-start-over-you-noob OR if it's perfectly normal. Halp?


Recipe for reference:
12 Liter (3-gallon) recipe
1 kg (2.2 lbs) Marris Otter Pale
250 g (0.55 lbs) Victory malt (28L)
125 g (0.27 lbs) Roasted barley (500-600L)
125 g (0.27 lbs) Carafa Special I (300-375L)
125 g (0.27 lbs) Crystal 70-80L
125 g (0.27 lbs) Oat flakes

1/2 oz Challenger Hops (bittering 60min)
1/2 oz Challenger Hops (flavouring 30min)
1/2 oz Challenger Hops (aroma 15min)
Irish moss to clear the wort a bit

Wyeast 1084 Irish Ale yeast smack pack. Created a starter from its content + some 10 °P (1.040) wort and lots of oxygen, shaken every half hour or so in an Erlenmeyer flask while I was working on the mash and boil. Looked healthy to my untrained eyes.

Ended up with a 1.052 wort, cooled it down to 21°C (69 °F), aerated like crazy, pitched my starter.

Images :

Exhibit A : the top-cake looking like crumpled graham crackers floating about


Exhibit B : the same floating bits at the bottom of the carboy -after- I (likely unwisely) gave a bit of a shake to the mixture.

It's similar to what I would expect from the Irish moss. RDWHAHB

CPT_Merica said:

It's similar to what I would expect from the Irish moss. RDWHAHB

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And that would set my mind at ease if I didn't know that I filtered my trub out, hops sludge, lipid film from boil, irish moss and all.

Could there have been some leftover that went through the filter and that's what I'm seeing?

Thanks for the quick answer, though

Cold Break?

Have you ever used the Irish yeast? I've found some of these fermentations to look rather different depending on the yeast. I wouldn't worry about it. If it's funkiness you'll know soon enough and either sour it for laughs or give it to some high schoolers.

beerandloathinginaustin said:

Have you ever used the Irish yeast?

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Wyeast 1084? I have on several occasions. Produced the same stout recipe at least once before (with some degree or success, meh) and a "two-penny" version of it (built from the spent grain of the first. A bit like low-ABV, watered-down cold coffee. Quaint but not exactly a success either.) So neither of those two batches would be references, though, except for the fact they didn't catch 'carboy flu' like this one.

I've actually seen cold break before while cooling my wort, but I've never seen this happen directly in the fermenter, which is part of why I'm currently worrying.

it looks like coagulated proteins & flocculation to me. how did you filter your wort prior to fermentation?

Billy-Klubb said:

how did you filter your wort prior to fermentation?

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Sad to say, all I had on hand was my siphon and the straight racking tube attachment with the little plug at the end. Pretty sure it let fine particles in.

AvianSavara said:

And that would set my mind at ease if I didn't know that I filtered my trub out, hops sludge, lipid film from boil, irish moss and all.

Could there have been some leftover that went through the filter and that's what I'm seeing?

Thanks for the quick answer, though

Click to expand...

AvianSavara said:

Sad to say, all I had on hand was my siphon and the straight racking tube attachment with the little plug at the end. Pretty sure it let fine particles in.

Click to expand...

So confused. You either filtered or you didn't. Either way there doesn't seem to be anything in your pictures that is concerning. It looks like coagulated proteins and yeast doing a happy dance

I recommend you name it Simon and begin a college fund, just in case

Well fellows, thanks for the tips, info, calm-the-heck-down-sonny and... name suggestions

Turns out it is the flocculation. My yeast might have gone a little too eager and did most of its work in the initial 24 hours. It has since settled into a much calmer pace.

I did indeed RDWHAHB, and after a quick sampling yesterday night, I'm proud to announce that it actually tastes like a stout. Another day or so before I rack it to a tight carboy with as little headroom as possible and consign it to my dark basement for another two weeks.