Hello all... new poster here. I've only been brewing for about 6 months and I've encountered an off-taste I can't seem to get rid of.
My first two batches came out fine with no off taste. The 5 or 6 since then have all had the same flaw, which is like a burnt plastic type of smell and flavor. I do mini mashes with bottled water with a 2 week primary and a 2 week secondary both in glass carboys and then bottle/keg. When racking to secondary, the smell is not yet noticeable, but when it is time to bottle, there it is.
The first time I got this flavor, I thought it was either wild yeast contamination or unclean equipment. So the next time I brewed, I cleaned all equipment thoroughly with oxyclean and sanitized with starsan (which I was doing before, but was especially attentive to this time). Also cleaned all deposits off kettle with PBW. I also cleaned all surfaces and floor of my kitchen so that that was also spotless. Flaw was still there at bottling time. Decided to switch to kegging.
The next couple times I thought maybe there was contamination in either my aqarium aeration equipment (I stupidly dunked the entire thing in sanitizer, getting the filter wet) or in my racking equipment. So I boiled the stone and bought a new filter and hose for aeration. Thought that there might be a scratch inside the siphon hose, so I bought new hose (which I upgraded to silicone hose) as well as a new auto siphon and racking cane. Also made sure to immediatley dunk in water after use and then to soak in warm oxyclean to prevent deposits from forming. Off flavor still there.
Up to this time I had not been using a yeast starter, so thought maybe underpitching was causing problems. Made a 700ml yeast starter for this batch, and pitched that. Also turned off AC so there would be no drafts at pitching time. Also turned off AC when it was time to rack. Lo and behold, the off flavor is once again there at kegging.
I honestly don't know how I could improve my cleaning/sanitation, short of a cleanroom. Wort is cooled quickly with combination ice bath and immersion chiller (which is boiled in the wort for last 10 minutes). These were all different recipes with different yeasts from a very reputable homebrew store. Yeast starters were all nice with a 1/2" of krausen. All fermentations were vigorous with quick start times and 2" krausen. None of the recipes were Belgians (save this last one which was a Belgian wit) or hefeweizens with funky yeast strains.
There are two problems that I can identify, however. The first is that the first few times I transferred the cooled wort to carboy I did it by by straining through a screen. This immediatley clogged with trub and I had to scrape it out with a sanitized spoon, which made the process take a little long, possibly exposing to airborne contamination. I then eliminated the screen and dumped trub and everything else in primary, which is probably foolish since it eliminates the gains from the hot and cold break. This next time I will do a whirlpool and then siphon to primary.
The second problem is fermentation temperature. The first two brews, which were fine, were fermented when the temperature outside was relativley cool. These fermented at about 65 degrees ambient temp. As it has warmed up they have been fermenting at a steady 73 degrees ambient temperature. I understand that inside the carboy the temp is probably higher, but is it TOO HIGH? Could too high of a ferment temp cause this off flavor?
Anyway, thanks for reading such a long post, and if you have any ideas/observations/questions I would love to hear them. Looks like a great community with a lot of knowledge!
My first two batches came out fine with no off taste. The 5 or 6 since then have all had the same flaw, which is like a burnt plastic type of smell and flavor. I do mini mashes with bottled water with a 2 week primary and a 2 week secondary both in glass carboys and then bottle/keg. When racking to secondary, the smell is not yet noticeable, but when it is time to bottle, there it is.
The first time I got this flavor, I thought it was either wild yeast contamination or unclean equipment. So the next time I brewed, I cleaned all equipment thoroughly with oxyclean and sanitized with starsan (which I was doing before, but was especially attentive to this time). Also cleaned all deposits off kettle with PBW. I also cleaned all surfaces and floor of my kitchen so that that was also spotless. Flaw was still there at bottling time. Decided to switch to kegging.
The next couple times I thought maybe there was contamination in either my aqarium aeration equipment (I stupidly dunked the entire thing in sanitizer, getting the filter wet) or in my racking equipment. So I boiled the stone and bought a new filter and hose for aeration. Thought that there might be a scratch inside the siphon hose, so I bought new hose (which I upgraded to silicone hose) as well as a new auto siphon and racking cane. Also made sure to immediatley dunk in water after use and then to soak in warm oxyclean to prevent deposits from forming. Off flavor still there.
Up to this time I had not been using a yeast starter, so thought maybe underpitching was causing problems. Made a 700ml yeast starter for this batch, and pitched that. Also turned off AC so there would be no drafts at pitching time. Also turned off AC when it was time to rack. Lo and behold, the off flavor is once again there at kegging.
I honestly don't know how I could improve my cleaning/sanitation, short of a cleanroom. Wort is cooled quickly with combination ice bath and immersion chiller (which is boiled in the wort for last 10 minutes). These were all different recipes with different yeasts from a very reputable homebrew store. Yeast starters were all nice with a 1/2" of krausen. All fermentations were vigorous with quick start times and 2" krausen. None of the recipes were Belgians (save this last one which was a Belgian wit) or hefeweizens with funky yeast strains.
There are two problems that I can identify, however. The first is that the first few times I transferred the cooled wort to carboy I did it by by straining through a screen. This immediatley clogged with trub and I had to scrape it out with a sanitized spoon, which made the process take a little long, possibly exposing to airborne contamination. I then eliminated the screen and dumped trub and everything else in primary, which is probably foolish since it eliminates the gains from the hot and cold break. This next time I will do a whirlpool and then siphon to primary.
The second problem is fermentation temperature. The first two brews, which were fine, were fermented when the temperature outside was relativley cool. These fermented at about 65 degrees ambient temp. As it has warmed up they have been fermenting at a steady 73 degrees ambient temperature. I understand that inside the carboy the temp is probably higher, but is it TOO HIGH? Could too high of a ferment temp cause this off flavor?
Anyway, thanks for reading such a long post, and if you have any ideas/observations/questions I would love to hear them. Looks like a great community with a lot of knowledge!