I switched to all grain years ago but came upon a recipe that i really wanted to try. However, it is an extract recipe with steeping grains. I brewed it twice and got a plastic off flavor both times. I use un-adjusted R.O. water and nothing but StarSan touches anything once I start brewing so I know it’s not chlorine. I used White Labs WLP001 which I have used several times before with no issues. The only thing I can think of is my plastic fermentation bucket but, again, I have used it before and since without issue. Any help out there?
Bottling or kegging?
Plastic usually means chlorine, but if you have ruled that out and if you are hitting all your numbers, is there any chance you have an infection in your end of the line distribution? Old hoses, bottles…etc. Just a thought.
Whenever I taste something that doesn’t seem right, I turn to an app called “BeerJudge”. I typed in the word “Plastic” and the app offered several different possibilities that cause a plastic-like flavor.
I force carb in the keg and then bottle with a beer gun. Flavor is present in both. I have been told that I am paranoid with my level of sanitation. Maybe I should try a different yeast?
Don’t think that it can’t be chloromines or chlorine in you water, even though you say RO water. At my brewery we once had a batch that turned out phenolic and we ruled out contamination (nice to have a full lab with a PCR that can check for infection at the genetic level.) Finally we determined that the day we brewed the batch the electricity had gone off. Our high tech water filter uses electricity to operate. We filled the HLT not realizing that our water wasn’t getting filtered. So let’s say the RO water you used (maybe you got it from the grocery store) had a similar issue… just a thought
Good thought. I’ve been using a chlorine test kit to confirm that my filters are still working acceptably.
Hach 223101 Chlorine (Free &… Amazon.com
Trust but verify.
Another off the wall thought. Could this perceived flavor actually not be chlorophenol, but from some other source, such as an unfamiliar hop or other ingredient? Was there anything novel about the recipe?
And yet the OP seemed to indicate that he used WLP001 and did not mention re-pitching. FWIW, it could have been contaminated with airborne wild yeast, especially at this time of the year and if brewing outdoors … in the time it takes to cool wort to pitching temp, if left uncovered, there is a distinct chance of contamination.
While I would not definitely rule out contamination I think switching to a different RO water source is a better first step. Contamination can be a tough problem to identify while testing water as the culprit is as simple as buying RO water from a different source. No added cost to your brewing or need to change your brewing practices.
When you say RO water, is it from your own 3 or 4 stage in home filtration system, or a “water mill” at the local grocer? Do you test the water pre-brewing to assure that all/most of the free and/or total chlorine was removed by carbon filtration prior to the RO membrane?
Water from those machines at the local grocer is only as consistent as the technician is in servicing them, especially during high use. I’d tested RO water from a machine and the pH was the exact same as our tap water (9.4) when it should have been much lower if the system was functioning properly.