Mysterious dark powder

[alecrippa]

Hi all,
I just bottled my ale and found a strange dark powder all over the fermenter's walls.

- The powder is so fine it disappears from the fingers if I run them together; think green-tee-powder-kind-of-fine

- it's black, or very very dark gray

- It was all over the fermenter ABOVE the krausen line and on the internal side of the lid (which was 25cm / 10" above the krausen line)

- It's kind of sticking to the steel walls of the fermenter as a sustained spray or my fingers could remove it, but just rinsing didn't seem to work

- Steel fermenter, cleansed and cleaned with ethanol before usage

- 2 weeks fermentation time @20deg Celsius

- Extract malt
- East Kent and Mosaic hops
- US-05 yeast

I would think of black mold, but I doubt mold can grow inside a fermenter after cleaning and during usage... or?

Here are ome pics:
The first one is the internal rim of the fermenter. The third and the fourth the bottom of my sinc after cleaning was done (with and without camera flash).

Thanks all for helping me figuring out what it is!

 

[day_trippr]

Mildew spores, or some other black mold, I expect.
Mild bleach/water mix on a rag should take care of the cabinet interior, the keg should come clean as well...

Cheers!

 

[alecrippa]

Important notes:
- The fermenter was not airtight.. the airlock never bubbled
- I opened it 3 days ago to dry-hop. I did not noticed / did not look for the black stuff

 

[IslandLizard]

You got a microscope?

I've had some black/gray mildew spots appear on the (air exposed) inside and the bottom of the lid in buckets holding Starsan. But that was after over a month of storage. Nothing looking like yours. Yours look like flakes.

 

[IslandLizard]

Steel fermenter, cleansed and cleaned with ethanol before usage

Why not using an alkaline cleaner (e.g., PBW) then an acid sanitizer (Starsan)?

 

[alecrippa]

Mildew spores, or some other black mold, I expect.
Mild bleach/water mix on a rag should take care of the cabinet interior, the keg should come clean as well...

Cheers!

Should I worry about health concerns?
I don't think I should drink that ale, should I?

 

[day_trippr]

Good question - but surely it didn't make it into the beer?

[edit] I re-read the first post. Totally missed it made it inside the fermentor. I still don't know what the implications might be but I'd be inclined to toss it.

I'm not sure there's any sanitation regime that will prevent mildew/black mold from appearing in a damp space eventually. Given it made it down around the keg lid I'd say everything was wet at some point, and unless the chamber is literally sealed mold will find a way in as the chamber "breathes" through cooling/warming cycles.

I'd say get a dehumidifying agent in there to stop the moisture from condensing all over the interior like that...

Cheers!

 

[Vale71]

It's oxidized hop resins. They rise with the Kräusen and turn black if exposed to oxygen which was readily available in your non-airtight fermenter. There's no health concern and if any made it back into the beer they will have sunk to the bottom with the rest of the trub.

 

[day_trippr]

So those black-on-white shots are from a sink - not your fermentation chamber - and came from inside the fermentor?
Man, comprehension is coming hard for me this afternoon, sorry 'bout that.

Never seen anything like that before...

Cheers!

 

[IslandLizard]

Should I worry about health concerns?
I don't think I should drink that ale, should I?

There's nothing (or not much) that can grow in beer that can make you sick.

If you carefully siphoned the beer out of your fermenter into bottles without the beer touching the sides of the fermenter or doing anything disturbing and suspending the clinging "mold" it should be safe, me thinks.

 

[IslandLizard]

It's oxidized hop resins. They rise with the Kräusen and turn black if exposed to oxygen which was readily available in your non-airtight fermenter. There's no health concern and if any made it back into the beer they will have sunk to the bottom with the rest of the trub.

Interesting you mention that.
I was thinking about hop dust, but couldn't connect to having that much of it around and deposited everywhere.

 

[alecrippa]

So those black-on-white shots are from a sink - not your fermentation chamber - and came from inside the fermentor?
Man, comprehension is coming hard for me this afternoon, sorry 'bout that.

Never seen anything like that before...

Cheers!

From the sinc where I poured the water I used for cleaning the fermenter

 

[alecrippa]

There's nothing (or not much) that can grow in beer that can make you sick.

If you carefully siphoned the beer out of your fermenter into bottles without the beer touching the sides of the fermenter or doing anything disturbing and suspending the clinging "mold" it should be safe, me thinks.

That "me thinks" though..

 

[alecrippa]

It's oxidized hop resins. They rise with the Kräusen and turn black if exposed to oxygen which was readily available in your non-airtight fermenter. There's no health concern and if any made it back into the beer they will have sunk to the bottom with the rest of the trub.

My initial thought, but how can hop jump up 20cm from the beer bed?

 

[IslandLizard]

That "me thinks" though..

I wrote that before I read @Vale71's post about oxidized hop resins.

But yeah, the general rule is that beer itself is an antiseptic due to low pH and presence of alcohol.

 

[alecrippa]

Good question - but surely it didn't make it into the beer?

[edit] I re-read the first post. Totally missed it made it inside the fermentor. I still don't know what the implications might be but I'd be inclined to toss it.

I'm not sure there's any sanitation regime that will prevent mildew/black mold from appearing in a damp space eventually. Given it made it down around the keg lid I'd say everything was wet at some point, and unless the chamber is literally sealed mold will find a way in as the chamber "breathes" through cooling/warming cycles.

I'd say get a dehumidifying agent in there to stop the moisture from condensing all over the interior like that...

Cheers!

What's weird is that the was no sign of it outside the fermenter.. just inside! The fermenter was sitting in my bathroom, which is relatively dry.

 

[Vale71]

My initial thought, but how can hop jump up 20cm from the beer bed?

That's how much the Kräusen grew before collapsing as fermentation slowed down. One downside (actually, the only one I can think of) of a stainless steel fermenter is that you won't see what's going on inside.

 

[alecrippa]

I'd say get a dehumidifying agent in there to stop the moisture from condensing all over the interior like that...

Cheers!

What can I use as dehumidifier?

 

[mongoose33]

I wrote that before I read @Vale71's post about oxidized hop resins.

But yeah, the general rule is that beer itself is an antiseptic due to low pH and presence of alcohol.

I can see that being a possibility from where the krausen left behind deposits in the krausen ring, but that is everywhere. Do hop resins deposit on all the interior surfaces, and only become apparent if oxygen is admitted?

I find it a little difficult to believe this as people use buckets all the time, they don't seal, they open them up to look. Now, maybe this is a unique circumstance, and maybe hop resins are vaporous and can deposit themselves everywhere....but I've never seen anyone complain about this before.

It looks more to me like mildew growing and if the fermenter was "cleaned" with ethanol...maybe those surfaces aren't as clean as one might think.

 

[alecrippa]

I can see that being a possibility from where the krausen left behind deposits in the krausen ring, but that is everywhere. Do hop resins deposit on all the interior surfaces, and only become apparent if oxygen is admitted?

I find it a little difficult to believe this as people use buckets all the time, they don't seal, they open them up to look. Now, maybe this is a unique circumstance, and maybe hop resins are vaporous and can deposit themselves everywhere....but I've never seen anyone complain about this before.

It looks more to me like mildew growing and if the fermenter was "cleaned" with ethanol...maybe those surfaces aren't as clean as one might think.

Agree - I highly doubt it could be hops as it's sparsely present everywhere, e.g. in between the threads of the lid.
On the other hand it doesn't look as the classic mold infection either, with areas of dense growth and/or hairy-looking spots.

Re alcohol, I'm puzzled. What better than a 70% alcohol solution can guarantee disinfection? Supposing I may have missed some areas, why would a mold grow everywhere?

Anyway I guess I'll toss the batch. Better safe than sorry.

You mentioned dehumydifying solutions: I never heard of them, can you please elaborate?

 

[IslandLizard]

Important notes:
- The fermenter was not airtight.. the airlock never bubbled
- I opened it 3 days ago to dry-hop. I did not noticed / did not look for the black stuff

1. Is this your first batch?
2. Is it your first batch in that fermenter? If not, how did previous ones turn out?
3. What was the form of dry hops you added? A sticky powder, pellets, flowers/leaves?
4. How long was the beer in the fermenter?
5. Your "steel" fermenter, is it stainless steel?
6. What is that vessel normally used for? The original purpose it was designed for?
7. Was/is there a coating of some sort on the inside? Dirt left behind from a previous batch or use?
8. How tight does the lid fit? Is there a rubber gasket? Or anything else that could have deteriorated
9. What yeast did you pitch?
10. Have you tasted any of that beer? What's it taste like?

To make it easy, you may answer by the number. Such as: 1. no, 5th

Mold takes time to grow. If there was nothing you noticed 3 days ago, when you dry hopped, and now it's "infested" it's not likely to be mold. Mold usually doesn't produce flakes either.

Alcohol is good sanitizer, but as soon as it evaporates (and it does so quickly) the surface is exposed to any microflora, dust particles, etc. in the surrounding air and environment, without protection. The sanitizers we (brewers) use keep the surface sanitary as long as they remain wet with it. That gives us some time to fill a bucket and snap a lid on.

In the U.S., Starsan and Iodine based sanitizers (e.g., Iodophor) are probably the most used or preferred among homebrewers. Both are no-rinse when used at the correct dilution (a no-rinse "working solution").
What's available in your country?

Alcohol is not a good cleaner. It dissolves certain things very well, but can't remove many others. I doubt it can remove dried on biofilm. An alkaline cleaner is much better at that. And using a scrub brush or (non-scratching) scouring pads. After the surfaces are clean, a good rinse off, followed by a sanitizer treatment, a 30-60 second dunk in a sanitizer bucket, mopped on, sprayed on, etc.

Sanitizing Rule #1:
You cannot sanitize something that's not clean in the first place.
IOW, you can't sanitize dirt.

 

[IslandLizard]

It looks more to me like mildew growing and if the fermenter was "cleaned" with ethanol...maybe those surfaces aren't as clean as one might think.

The flakes are weird. They're all over his sink. I've never seen mildew or black mold flake like that.
Maybe stuff growing underneath the top rim?

I'd like to see a picture of that whole fermenter, lid and all. With those rolled edges it looks like some sort of keg.

 

[mongoose33]

Agree - I highly doubt it could be hops as it's sparsely present everywhere, e.g. in between the threads of the lid.
On the other hand it doesn't look as the classic mold infection either, with areas of dense growth and/or hairy-looking spots.

Re alcohol, I'm puzzled. What better than a 70% alcohol solution can guarantee disinfection? Supposing I may have missed some areas, why would a mold grow everywhere?

See @IslandLizard's post. You'd have to saturate all the organic matter with alcohol for it to work, and dirt often forms a dried crust which resists that. If you have a layer of organic matter you can't be sure of sanitizing it, and I'd bet you didn't if that's what happened.

Clean first, then sanitize.

Anyway I guess I'll toss the batch. Better safe than sorry.

Oh, I doubt it's hazardous. You'll be able to tell if it's infected by overcarbonation and a sharp taste.

BTW: at our LHBC meeting this month one guy brought a bottle of English Bitter that foamed like crazy when he opened it. When it finally settled down I tried a taste--still overcarbed and I could taste the infection immediately.

Here's what might be of interest to you: he said he'd bottled several bottles and only this one had a problem. He had to have had some sort of crud in the bottle he didn't get cleaned, and then there you are. Infected.

You mentioned dehumydifying solutions: I never heard of them, can you please elaborate?

That was @day_trippr who said that. He was probably referring to a device like this: https://www.amazon.com/gp/product/B000H0XFCS/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

*********

BTW, all this is simply a learning experience. Everybody has issues with brewing; the mistakes just become more profound as they move forward.

I figure every time I make a mistake I learn something. By now, I figure I must be a genius.

 

[alecrippa]

1. Is this your first batch?
2. Is it your first batch in that fermenter? If not, how did previous ones turn out?
3. What was the form of dry hops you added? A sticky powder, pellets, flowers/leaves?
4. How long was the beer in the fermenter?
5. Your "steel" fermenter, is it stainless steel?
6. What is that vessel normally used for? The original purpose it was designed for?
7. Was/is there a coating of some sort on the inside? Dirt left behind from a previous batch or use?
8. How tight does the lid fit? Is there a rubber gasket? Or anything else that could have deteriorated
9. What yeast did you pitch?
10. Have you tasted any of that beer? What's it taste like?

To make it easy, you may answer by the number. Such as: 1. no, 5th

Mold takes time to grow. If there was nothing you noticed 3 days ago, when you dry hopped, and now it's "infested" it's not likely to be mold. Mold usually doesn't produce flakes either.

Alcohol is good sanitizer, but as soon as it evaporates (and it does so quickly) the surface is exposed to any microflora, dust particles, etc. in the surrounding air and environment, without protection. The sanitizers we (brewers) use keep the surface sanitary as long as they remain wet with it. That gives us some time to fill a bucket and snap a lid on.

In the U.S., Starsan and Iodine based sanitizers (e.g., Iodophor) are probably the most used or preferred among homebrewers. Both are no-rinse when used at the correct dilution (a no-rinse "working solution").
What's available in your country?

Alcohol is not a good cleaner. It dissolves certain things very well, but can't remove many others. I doubt it can remove dried on biofilm. An alkaline cleaner is much better at that. And using a scrub brush or (non-scratching) scouring pads. After the surfaces are clean, a good rinse off, followed by a sanitizer treatment, a 30-60 second dunk in a sanitizer bucket, mopped on, sprayed on, etc.

Sanitizing Rule #1:
You cannot sanitize something that's not clean in the first place.
IOW, you can't sanitize dirt.

Hi,
Thanks for tour help!
Here my answers:
1) no, but my last time was years ago
2) no, it's still the equipment I used years ago
3) pellets
4) two weeks. I can't exclude the black dots were there when I opened it for dry hopping, but I did not see them
5) stainless steel
6) its original design is a tank for olive oil (https://www.ebay.it/itm/CONTENITORE...MAGGIO-FUSTINO-FUSTI-/142563367055?nav=SEARCH)

I used it only for beer, but it was waiting for me in the garage for years

7) There shouldn't have been, I did my best to clean it before hand
8) large rubber gasket. It still looks fine but it's probably deteriorated as the seal was not air-tight anymore
9) safale us-05
10) It tastes very fine
My concern is that if it's mold, and if it's toxic, I would not be comfortable in drinking or sharing it. Isn't so that kold can be extremely toxic?

To answer your other questions, the cleaners and sanitizer I can easily find here are :
Cleaning: Chemipro (OXI, ACID, Caustic), citric acid
Sanitizing: Chemipro (SAN, CIP)

 

[alecrippa]

The flakes are weird. They're all over his sink. I've never seen mildew or black mold flake like that.
Maybe stuff growing underneath the top rim?

I'd like to see a picture of that whole fermenter, lid and all. With those rolled edges it looks like some sort of keg.

https://www.ebay.it/itm/CONTENITORE...MAGGIO-FUSTINO-FUSTI-/142563367055?nav=SEARCH

This is it - or something very similar. I went for it as it's cheaper than similar containers ised in brewing. The disadvantage is that the tap is only 2-3 cm from the bottom of the tank.

The lid is 15cm/10-12" wide and 5cm/2" high. It has a large thread around it so that it can be screwed in place with 2-3 turns. There is a gasket all around the upper part of the lid that is supposed to seal the whole thing