[larsmm]

Hello,

This is my first post in the forum. Thank you very much to those who want help me and sorry for (I guess) some mistakes in "my English".

I started brewing a bit more than a year ago and the four first times I got beer, as I expected, ones better than others. The forth time I had a "great" idea: a friend of mine has a factory of cure meat and I thought I could leave a secundary fermenter for a couple of weeks in a refrigerating chamber of his factory at 32 -35 ºF, in order to get a very clear beer. I got it, perfectly clear.

But from that moment on I've just been getting contaminated beer (I think for nine or ten times). I've cleaned everything carefully, using even NaOH solution and rinsing with a mix of acetic acid and hidrogen peroxide, including heat treatment (p.e. I put the chiller, valves and silicone pipes in a oven for 36 hours at 250 ºF), replacing fermenters by new ones, replacing airlocks by blow-off tube... Last time I bought a ozonizer (not high quality, 400 mg/h) and tried to "clean" the place where I brew: 1 hour per day for 7 days in a row, but always the allien wake up and get inside my beer.

What kind of contamination? I'm not sure, but it's something hard-sour, specially in the nose. It begins at the beginning of the fermentation, I mean, even the day after the brewday I can smell it. Also I can see a white foam at the top of the fermenter.

Why I say a "great" idea, with reference to the two weeks in the refrigerating chamber? Because in that kind of chamber there are lot of bacterias. I suppose that some bacterias set in the surface of the fermenter. Because the airlock, those bacterias couldn't get into the fermenter, but survived outside and settled the brew place. So they are in the air. It's just a supposition.

I oxigenate saking the fermenter, just before pitching the yeast. Maybe I could improve the procedure using oxigene, but I saked the four first times and I hadn't got any problem.

Have you got an idea to solve this situation? I'd be very pleasant if you can help me. Thank you very much.

[morticaixavier]

Have you used different yeasts over these last 10 batches?

Where do you grind your grain in relation to your fermenters?

do you have fruit flies in your house at all?

Can you compare the sourness to either vinegar or plain yogurt/sour cream?

man that's rough by the way. good job hanging in there

[kramerog]

When you say you see white foam are you seeing pellicle which is shown in the first twenty or so pictures at

https://www.google.com/search?q=pellicle+beer&espv=2&biw=1144&bih=916&tbm=isch&tbo=u&source=univ&sa=X&ei=M9orVfzOMIuwggT_w4OICw&ved=0CB0QsAQ&dpr=0.9

[larsmm]

morticaixavier:

I always use dehidrated yeast, most of the times Safale 04 - US05.

I always grind in a different place to the brewhouse.

I think there's no kind of fly at winter at home. I think I've never seen a fruit fly in the brewhouse.

I'd say the sourness at mouth is much softer than vinegar. But it smells so acid. Have you ever smelt an acid in a lab? When you open the fermenter and put the nose at the top of it, there is something that makes you move your head back. But doesn't stink; just acid.

kramerog:

It's a soft foam, like soap foam, mix in the top with the yeast. There is no kind of thread, or bubbles with white dust, or a veil...

I haven't said yet. I boil for at least 75 minutes.

[kramerog]

Do you shake the ferment to oxygenate?  It seems you do, but I just want to check because, an oxygenation "stone" could be a source of infection.

Do you sanitize everything after the boil immediately before you use it?  How?

[larsmm]

Do you shake the ferment to oxygenate?  It seems you do, but I just want to check because, an oxygenation "stone" could be a source of infection.

How do you sanitize everything after the boil immediately before you use it?

Yes, I sake the ferment. Previously, I let the cold wort falls to the fermenter from 3 ft in order to get some aeration. I've never used a stone yet.

First times, before contamination, after boiling I cleaned all the stuff with washing-up liquid and rinsed with water. Before using mash tun, hlt and kettle I cleaned them again with washing-up liquid. The rest of the stuff, I soaked it in hot water with sodium percarbonate (chemipro oxi) and didn't rinse it.

Now, I've tried many ways. The hardest: after cleaning with wahing-up liquid, NaOH hot solution followed by Acetic Acid + hydrogene peroxide + chemipro oxi solution.

Thank you very much for your help.

[euge]

You might have picked up something from your friend's operation. If he is fermenting sausage it often is a lactic-type of bacteria to drop the pH of the meat down to inhibit pathogenic organisms.

[majorvices]

Are you sure you are not misdiagnosing the problem as an infection? I say that because it is almost impossible for an infection to initially out compete the yeast, unless you are purposely inoculating the batch with wild "bugs". Even if you had fermented an all brett beer in a scratched bucket there is no way the brett cells could out compete a packet of dry yeast. You say you see a white foam on top of the fermentor, but you should have foam, it's called krausen. I'm not sure why that would be indicative of a problem. So perhaps you are picking up some other off flavors and mistaking them for infection?

What temp are you fermenting? Are you filtering your water? Are you completely cooling your wort before pitching yeast? What temp are you pitching yeast?

[majorvices]

You might have picked up something from your friend's operation. If he is fermenting sausage it often is a lactic-type of bacteria to drop the pH of the meat down to inhibit pathogenic organisms.

Now, once I harvested yeast in an old pickle jar and the pickle jar did smell like pickles even after it was cleaned, set in sun several days and sanitized. Sure enough the beer smelled like sour pickles. I used the jar for pickles only after that!

[euge]

I think the most important thing here is how does the beer taste? Because if one just goes by various fermenting smells- got turned off and never tasted the brew that would be a huge error.

[larsmm]

Are you sure you are not misdiagnosing the problem as an infection? I say that because it is almost impossible for an infection to initially out compete the yeast, unless you are purposely inoculating the batch with wild "bugs". Even if you had fermented an all brett beer in a scratched bucket there is no way the brett cells could out compete a packet of dry yeast. You say you see a white foam on top of the fermentor, but you should have foam, it's called krausen. I'm not sure why that would be indicative of a problem. So perhaps you are picking up some other off flavors and mistaking them for infection?

What temp are you fermenting? Are you filtering your water? Are you completely cooling your wort before pitching yeast? What temp are you pitching yeast?

I've never brewed with brett or other kind of "special" yeasts.
What I see on the top of the wort is a mis of krausen and white-shoft foam. Both are different.

Maybe I can be confused, but the four first times I never got an acid smell, so strong and "painfull". And when I taste it I notice undobtly an sour and undesirable taste.

I usually ferment at 68 °F + - 2°. And when I pitch, wort temperature is aroun 70.

Thanks a lot.

[larsmm]

You might have picked up something from your friend's operation. If he is fermenting sausage it often is a lactic-type of bacteria to drop the pH of the meat down to inhibit pathogenic organisms.

Now, once I harvested yeast in an old pickle jar and the pickle jar did smell like pickles even after it was cleaned, set in sun several days and sanitized. Sure enough the beer smelled like sour pickles. I used the jar for pickles only after that!

I prepare the yeast in a clean glass, used for water. I don't like pickles so it's not possible.

[larsmm]

I think the most important thing here is how does the beer taste? Because if one just goes by various fermenting smells- got turned off and never tasted the brew that would be a huge error.

I always taste the beer and I always get a persistence sour taste in my mouth. a couple of times I let the beer get a bit older but the problem became worse...

[majorvices]

Do you filter your water?

[morticaixavier]

Can you get idophor or star san? you might just need to shock your system with something new. you might even do a bleach wash down on everything. Rinse well after.