I have been a big fan of all the exBEERiments taking place over on brulosophy.com but I my be letting all their statistically insignificant data carry over into some actually significant brewing processes - I have neglected some cleaning/sanitizing and have been using unhealthy yeast.
Brown Ale Infection
For the brown ale, I have narrowed down the cause of the infection to three potential areas
- Unboiled DME
- Ball valve
- Contaminated yeast
I think my infection came from 1 or 3, while its possible number 2 was the cause, I think its slim.
1) A little back story - when I kegged my brown ale I cleaned and sanitized my quick disconnect and silicone tubing and I sprayed starsan in and around the quick disconnect on the pot's ball valve. I then attached the hose and gravity drained right from the kettle into a cleaned and sanitized keg. I grabbed a plastic cup in the brew area and weighed out the DME to use in the keg for carbonation. I dumped it right in the keg (didn't boil it) and let it sit for a little over 3 weeks to naturally carbonate.
When I hooked up the keg and pull some off, it was all foam and had a very sour note. I did my research and new I was overcarbonated and it was most likely caused from an infection. I off-gassed the keg twice a day for over a week until it finally was not pouring foam. The samples were getting less sour, but they were taking on new off flavors - phenolic, clove, spicey, and a slight "meaty" note all accompanied with an astringent bitterness. The sourness had faded but this beer was not getting better.
Just like a baseball skipper, I made the call to pull my pitcher and dump the brown ale...
[moment of silence for dumping 5 gallons of alcohol]
Life is too short to drink bad beer!
2) Anyways, I did save a bit of the sample to test and the gravity had dropped 2 points from 1.011 to 1.009 so something unintended definitely got to work in that beer. As you can see from the pictures below, even though I clean out my ball valve and boil kettle after each brew, some stuff gets in those threads. I have since disassembled and cleaned all of those parts. I also don't think I am going to be fermenting in the kettle anymore - probably not the cause of the potential grime, but I prefer to see what is going on in the clear better bottles anyways.
|You can see the dirt in the 7 to 8 oclock quadrant of the valve|
|Same picture with slightly different lighting|
|Flecks of crud on a napkin after brush out the inside of the ball valve|
3) The last possible cause for my infection could have been the yeast. I harvested the WLP002 from inTROduction ale by just pouring the yeast slurry from the better bottle into a mason jar which had been boiled. It should have been fine, but who knows what was kicking around in the air from the time I finished racking to the keg, until dumping the yeast slurry. It also took a good 2 days for that yeast to show signs of fermentation. Definitely plan on making a vitality starter next time.
Off Flavor in Blonde Ale?
So I just kegged my blonde ale on Saturday and taking a swig from my final gravity sample I found myself shaking my head in shame again. I tasted a little bit of a vegetal character, much like V8 tomato juice. This is where I am really interested to see how this beer turns out after carbonation - did I get DMS from the 30 min boil? Or was it the slow start to my fermentation? A statistically insignificant exBEERiment would state it wasn't the boil time, but instaed was caused by the slow fermentation.
Yeah, you caught that did you? I had an even slower start to my fermentation in the blonde ale than I did with the brown! I used WLP090 San Diego super yeast which was a few weeks past its best by date. I was TOO LAZY to make a starter, so I just took 2 L of my blonde ale wort and added the yeast to the stir plate. About 8 hours later I pitched the yeast and wort into the rest of the wort to ferment. It took right under 72 hours for it to start to fermenting - not optimal
I have been to lazy to make sure my yeast is at optimum health and pitch rate to ferment my beer to its best potential. I need refocus my efforts toward better brewday preparation. I will update when i have a better idea about how the blonde turns out. If it is DMS I am going to have a constant inner battle with whether it was the 30 minute boil, or the slow fermentation start.
I can control both of those variable in my next brew.
Until then...everyone hug your uncontaminated and off-flavor-free beers for me. You don't know how much you should appreciate them :)