My last two beers had diacetyl, butter flavor

[nthammer]

As the title states, the last two beers I brewed had strong butter flavors. VERY disappointing as I haven't had butter beer since my second batch ever, probably 2 years ago.

Looking back at my brewing process, and trying to figure out what sets these beers apart from the rest, this is what I've come up with.

1. I've gotten cocky with my fermentation, and racked these beers after only a week in primary, as I knew they were at FG. I generally do 2-4 weeks.

2. I used dry yeast without re-hydration (s-04 in one s-05 in another). Although I have done this once or twice before, it is certainly not the norm for me. this means very long lag times.

3. My star-san bucket is as old as it's ever been, and very cloudy. Approaching 6 months I think. I use tap water to mix my solution.

4. I have a fermentation chamber that can control temperature, but only for cooling. I have not wired in heating yet, so once rigorous fermentation stops, the temperature drops down to ~60F. I do have a 'reptile cord' that I plug in and monitor to bring it back up to mid-high 60's but I unplug it at night and when I leave for work. So there is temperature fluctuations. I have made beers recently though under the same conditions and they were fine, but being deep in winter now, this is not the norm.


So I made a nut brown ale last weekend that I'm hoping turns out well, I used a wyeast smackpack that I allowed to swell for hours. ( yeah I made a starter for my beer this weekend because I actually planned ahead), I made a new solution of star-san, and I plan on leaving this one in primary for at least 2 weeks, maybe 3.

Do any of you think I could still be doing something wrong? I will update on my current beer when it's kegged

 

[flars]

Longer primary time for the yeast to clean up the diacetyl should help. Unstable wort temperature may compound the problem.

 

[kegtoe]

Really hard to troubleshoot for you not knowing the whole process, but you did a good job detailing some of your observations. You really should change your StarSan. Cloudy isn't good (might not be bad either) but I don't chance it. You can use a pH strip to check what it is. Of all the things to go cheap on of skimp on, sanitation should be the last. Tap water can make starsan go bad in a hurry. I started buying RO water from grocery store. The extra cost is really negligible as the solution holds up far better. I keep mine in a 5 gal food safe bucket with a gamma lid.

 

[nthammer]

Yeah as I've been reading it seems RO water is the way to go so Im going to get some to mix up a new san solution

 

[maffew222]

I think you answered all your own questions really. It may not be one specific thing that are causing the diacetyl but a combo of many. Get as many things in order as you can. I would definitely start with the sanitizer as then you can be at least a little more sure of eliminating infection outside of the diacetyl prob. If the fermentation temp is a problem, maybe find a yeast that does better in the high 50s low 60s to avoid the temp swing.

 

[nthammer]

I'm just wondering if other people had experienced issues with diacetyl and what they did to fix it.

 

[Flyboy84]

I'm just wondering if other people had experienced issues with diacetyl and what they did to fix it.

Diacetyl is made in the first few days of fermentation. The best thing you can do is proper yeast pitch amounts and temp control during fermentation.

Check out this link:
http://morebeer.com/brewingtechniques/library/backissues/issue1.2/fix.html

 

[GRBC]

If you are kegging, also consider the possibility that your poppers/lines/taps are infected. In addition to fermentation issues, a Pedio infection can produce diacetyl.

 

[Gingie]

I'm just wondering if other people had experienced issues with diacetyl and what they did to fix it.

I had this issue in the bottle. I tasted my OG and FG samples, and there was no butter taste, but it was very present after bottling conditioning in the two bottles that were sampled. Along with an oily mouthfeel (which my wife described as really smooth, in a good way, god bless her). Bottles were conditioned for 10 days at 64F.

I brought them upstairs where its around 72F for a week, and then back to the basement for another week at 64F. Chilled in the fridge overnight and that got rid of the diacetyl taste altogether.

 

[ColoHox]

3. My star-san bucket is as old as it's ever been, and very cloudy. Approaching 6 months I think. I use tap water to mix my solution.

Are you really using 6 month old, cloudy starsan? Is that a thing? Do other people do this? Fresh Starsan is probably the most often used piece of brewery equipment I have.

Both Lactobacillus and Pediococcus can produce diacetyl and they are EVERYWHERE. Cloudy starsan has lost its surfactant component, so it is not as effective.

Diacetyl can also be formed through oxidative processes. If your beer is exposed to too much oxygen after fermentation, you will have increased diacetyl.

 

[Natdavis777]

What popped out to me was the drop in temp after fermentation. My very first beer was a butter bomb. I see it as something similar to a "taste aversion" in that I'll never forget what I did wrong. I diacetyl rest every beer now. Doesn't take any extra time, but has ensured every beer since has been diacetyl free.

I happen to have a dual stage chamber, but with temps in the single digits and the chamber in my garage, 66F seems to be my highest temp this winter. So once I see the Krausen start to fall in my beer (typically ferment ~62F), I'll bring it in the house. The temp slowly raises for the remainder of the fermentation (last 20%) and all the compounds are consumed. Most ales take me 14 days in the primary. If it's big, I'll go three weeks. Better safe than sorry.

Your off flavors are going to develop in the beginning of fermentation, when the yeast is multiplying. High temps, stress, etc are going to exacerbate these off flavors.