Possible diacetyl infection?

[user 264271]

Hi everyone.

I recently brew this beer (#1):

I added half a pound of table sugar to bump up the alcohol content (I don't really know if that's a good idea) and it was the first time I did so.

Before this (3 weeks earlier) I brewed another IPA (#2), that currently bottle conditioning, and so far so good.

My previous brew was an English IPA (#3) that resulted in bottle gushers.

The one before that was a Tripel Karmeliet clone (#4) that made use of SafAle German Ale (DCL/Fermentis #K-97) yeast.

Anyway, I post this little batch history so hopefully you can help me track the source of the problem. I don't know if this could be realted to the SafAle German Ale yeast residuals somewhere in my brewhouse or not?

Anyhow, I brewed said beer (#1) and I immidiatelly noticed a off-smell, kind of like "chicken broth", fatty, maybe buttery smell and taste that according to the Internets might related to diacetyl.

The beer was also very, very cloudy, I wasen't expecting this.

I dumped the whole batch but didn't notice anything strange once I opened the lid, other than a thicker than usual gunk at the bottom of the stainless steel fermenting tank.

Other than that all looked normal, no sign of infection or anything, just the off smell and taste, cloudier than expected and the thicker gunk at the bottom.

BTW, the OG was 1,069 and the FG was 1,016 (measured several times a few days apart and what the recipe called for).

Could this has been related to
- an infection (poor sanitation, although I think I did a good job at that)
- a residual of the SafAle German Ale (DCL/Fermentis #K-97) yeast that promoted the creation of diacetyl.
- the yeast that I used, low cell count for the strenght of the beer (ABV 7,2%)
- temperature fluctuation during fermentation (I fermented for 2 weeks and at some point the temp drop to 15 degrees or so)
- something else?

Thanks everyone!

 

[RPh_Guy]

This definitely could be the result of a contamination, but likely it would be wild yeast rather than residual commercial yeast.

Was this a 10 liter batch or...?

How long was it in the fermenter and what was the temperature schedule?

How are you currently cleaning your equipment?

 

[user 264271]

It was a 10L batch.

Worth fermented for 2 solid weeks.

I have no way to temp control fermentation, it naturally oscilated between 20C and 15C I beleive.

I clean my equipment with star-san.

Very sad I had to dump the whole batch

 

[RPh_Guy]

I clean my equipment with star-san.

This may be an issue.

Star San is a surface sanitizer, not a cleanser. It does not clean surfaces and it does not sanitize surfaces that aren't clean.

Soaking your equipment in warm/hot water mixed with a good alkaline cleanser like "Powdered Brewery Wash" (PBW), "Alkaline Brewery Wash", Oxiclean, or something similar with sodium percarbonate is part of a good cleaning procedure.

Star San should be used on clean equipment right before it comes into contact with your chilled wort or beer.

Hope this makes sense.

 

[user 264271]

I beleive this could then be an issue, yes.

After I finish my brew day, I clean my equipment with hot water an no much else, and I store it.
It is stainless steel and it "looks" clean.

On my next brew day, I simply sanitize the equipment with start-san, but I do not clean the equipment whatsover.

Have I been doing my cleaning/sanitation wrong?

 

[RPh_Guy]

Have I been doing my cleaning/sanitation wrong?

Yes. Cold side equipment (everything that touches the wort after it's chilled and the subsequent beer) needs a thorough cleaning.

 

[user 264271]

Sounds good, It seems that this was the problem.
I'm brewing another one today and manually cleaned all equipment thoroughly and desinfected with StartSan as usual.
I didn't do any cleaning with those alcaline or acid products.
Is this enough?

Thanks

 

[RPh_Guy]

manually cleaned all equipment thoroughly

How did you clean exactly?

PBW or similar alkaline cleanser does a really good job removing organic residue.
For cold side equipmentment I recommend a hot soak in PBW, and disassembling everything that comes apart for the soaking, and then a water rinse, acid rinse, and water rinse afterwards.


Star San by itself is not enough:

Star San is a surface sanitizer, not a cleanser. It does not clean surfaces and it does not sanitize surfaces that aren't clean.

 

[user 264271]

I disasembled everything and then cleaned the equipment with just soap and water and then used StarSan.
I am just learning about alkaline and acid cleaning. SHould I use PBW and an acid cleaner every single time after brewing?

 

[VirginiaHops1]

FWIW, now that I'm fermenting in kegs I rarely use oxyclean anymore. I find just rinsing with hot water(sometimes letting it soak for a bit) and then scrubbing the hard to get stuff with a sponge is enough. Then sanitize before reuse. The heavy duty cleaners were very useful when I fermented in plastic though because you really can't scrub that, because it can scratch so easily. I add this because I noticed you're fermenting in SS, but ultimately your cleaning methods should be whatever gives you the highest level of comfort.

 

[RPh_Guy]

SHould I use PBW and an acid cleaner every single time after brewing?

That's what I recommend, at least on cold side equipment.

You can get away with doing less but it increases risk of contamination.

 

[dwhite60]

Could have just been simple impatience too. Cleaning up diacetyl takes time. I would have at least bottled some of it and given it three weeks. Amazing things happen in the bottle.

All the Best,
D. White

 

[Navy Guy]

Just as an FYI, you can't get a diacetyl "infection" as it isn't a living microbe. It is a by-product of yeast production. You need time and possibly higher temperature to get rid of it. English yeasts tend to be strong producers of it.