Contamination Issue

[SeattleBrewer]

So I am pretty sure my last batch was contaminated somewhere along the process. I was brewing a honey lemon wheat beer and I put the honey in at the 15 minute mark (to flame off) and I think that might be where the contamination happened. I also put the lemon zest in at flame off. After four days in my primary fermenter it had a "dirt" smell too it and the taste was even worse.

I did sterilize all my equipment with bleach. And then rinsed, I guess there might be a chance that when I rinsed I reintroduced something. Not sure and wondering of anyone has any ideas of what one wrong.

Do you think I should have boiled the honey longer? Could the lemon have introduced it. Never had this problem before and it wasn't fun dumping that much work and money down the toilet.

Any thoughts or ideas help!

 

[McCoy]

What was your chilling process like? How did you pitch the yeast? It could be something from the honey or lemon, but I doubt it. Honey doesn't carry much of a microbe population even if it's unpasteurized as far as I know. It's more likely that it came from the lemon, but at boiling temperatures (like at flameout) most microbes won't survive more than half a minute, so I would be surprised if the contamination came from either of those additions.

Also a "dirt" smell (do you mean literally like potting soil?) does not necessarily mean that your beer is contaminated. All kinds of smells can result from healthy fermentation. Take a sample, see how it tastes. Did you get a regular krausen? Are there any usual looking things in the fermenter (a pellicle? ropey strands?)?

 

[SeattleBrewer]

Thanks for the questions.


The "dirt smell" was like a moldy moss smell. Kinda that dirty small after camping. Just "earthy" and not in a good fresh smelling way. Kinda stagnate.

Pitching I used one of the slap packs. I broke the packet about four hours before I even started brewing. I brought the wort down to about 75 degrees F (using a digital food thermometer).

For cooling I used ice and running water around the outside (with lid on) of my brew pot. Total time according to my notes was just under 20 minutes for 5 gallons of wort.

Hope this helps diagnose my screw up.

 

[Hex23]

Was the digital food thermometer sanitary?

What yeast did you use? Some wheat yeasts can have a dank sort of earthy flavor, IMO. Have any pictures of the surface of the fermentation?

I'd totally ditch the bleach and rinse method. Starsan in a spray bottle is very easy to use and effective. I've never had a single infection.

75 is a little high to start fermenting at. What was ambient temp? If you add in the exothermic nature of the yeast it would not be surprising if it could have reached high 70's or more. That could lead to yeast stress and off flavors.

 

[McCoy]

Also many people use a spray bottle to sanitize the smackpack before pitching. Hex is on the mark with his questions too.

 

[SeattleBrewer]

Thanks for all the feedback, Hex here are the answers to your questions.

I did sterilize the thermometer before use. I sterilize all the equipment before each batch.

Ambient temp in my apartment was hovering around 70 degrees that weekend.

Type if yeast was a Belgian. I forget the exact strain, I'm away from home and don't have my notes with me, but it wasn't a wheat.

I have been reading about the Starsan, so far it seems that's what everyone uses. Does it impart any off flavoring since I know you don't have to rinse it?

 

[Hex23]

With ambient temps around 70, it's possible the fermentation was in the mid 70's or higher, especially for a Belgian strain. Many Belgian strains can take higher temps. But, depending on the strain I would not be too surprised for it to create an earthy flavor, especially at higher temps. If this is the case, often those flavors will subside with time. If it's truely an infection, those flavors probably won't. But i think you said you dumped it, right?

As long as you're not leaving alot (and I mean ALOT) of the star-san liquid behind it will not impart any flavor. Diluted star-san solution itself will taste a little tart because it's acidic, but the minor amount typically left behind is not enough to impact pH or flavor.

 

[McCoy]

Did you happen to taste the wort at any time before fermentation began? Did you use extract? Partial mash? I've made at least one terrible tasting batch that had nothing to do with infection and was more likely due to unhappy yeast or tannin extraction during a poorly conducted partial mash.

I've gotta say in general I am inclined to think that you didn't have an infected batch. There are quite a few reasons that a brew can go wrong that has nothing to do with infection. It's not exactly easy to get an infection. That said, infections can show up when you haven't done anything wrong (that you know about at least). But one of the things that really brought me peace of mind was trying to brew a wild fermented mead in a mason jar in my apartment. I left it exposed to air and for two weeks nothing took up residence in it. Only after two weeks a bit of mold started growing on the surface. Not exactly an experiment or statistically significant, but it surprised me.