Hi all,
As per the thread title, this has now occurred with 2 separate all grain brews (though an intervening brew was top notch). I think I've worked out what the issue with both was, but keen to hear thoughts and general discussion around this issue, and perhaps how to control/prevent this from happening in future.
The first was a Marzen/Oktoberfest lager. I only had 1 Wyeast Munich Lager smackpack (and on reflection should have made a starter). However the Wyeast website reassured me by suggesting starting fermentation at a warmer temp (18-22c ish) before lowering to normal lager fermentation temps.
I pitched the yeast at around 13c, but then naturally warmed at room temp to 18c ish to get the yeast active. This took 3 days before activity, the beer met it's FG fine in a temp controlled fridge, but resulted in a very strong TCP off-flavour/aroma. 12 bottles saved for reference, otherwise it was binned.
The second brew was an English Bitter. The wort went into the stainless steel fermenter at 25c but rapidly cooled to 12c due to the winter temps! I had to wait 3 days in a temp controlled fridge to get it to yeast (S-04) pitching temp of around 18-19c. Fermentation was perfect and FG was met after a week or so. However the TCP flavour has returned.
In both brews 1/2 a crushed campden tab was used in the water. I clean (then thoroughly rinse) with ChemiPro Wash and sanitise with StarSan no rinse. So I don't think it's a chlorine related issue.
My conclusion is that despite the stainless FV being cleaned, sanitised and sealed, in the 3 days waiting for the wort to "warm up" somehow an infection manifested and created some crazy esters in the wort. I'm pretty fastidious with cleaning/sanisiting, so perhaps it could be something else causing the off-flavours?
In future I'll transfer the wort to the FV at a higher temp and allow the stainless to cool it to pitching temp. Then pitch as soon as possible to get yeast activation started.
Interested to hear anyone else's thoughts or experiences with this and any tips or pointers to help in the future.
Thanks!
As per the thread title, this has now occurred with 2 separate all grain brews (though an intervening brew was top notch). I think I've worked out what the issue with both was, but keen to hear thoughts and general discussion around this issue, and perhaps how to control/prevent this from happening in future.
The first was a Marzen/Oktoberfest lager. I only had 1 Wyeast Munich Lager smackpack (and on reflection should have made a starter). However the Wyeast website reassured me by suggesting starting fermentation at a warmer temp (18-22c ish) before lowering to normal lager fermentation temps.
I pitched the yeast at around 13c, but then naturally warmed at room temp to 18c ish to get the yeast active. This took 3 days before activity, the beer met it's FG fine in a temp controlled fridge, but resulted in a very strong TCP off-flavour/aroma. 12 bottles saved for reference, otherwise it was binned.
The second brew was an English Bitter. The wort went into the stainless steel fermenter at 25c but rapidly cooled to 12c due to the winter temps! I had to wait 3 days in a temp controlled fridge to get it to yeast (S-04) pitching temp of around 18-19c. Fermentation was perfect and FG was met after a week or so. However the TCP flavour has returned.
In both brews 1/2 a crushed campden tab was used in the water. I clean (then thoroughly rinse) with ChemiPro Wash and sanitise with StarSan no rinse. So I don't think it's a chlorine related issue.
My conclusion is that despite the stainless FV being cleaned, sanitised and sealed, in the 3 days waiting for the wort to "warm up" somehow an infection manifested and created some crazy esters in the wort. I'm pretty fastidious with cleaning/sanisiting, so perhaps it could be something else causing the off-flavours?
In future I'll transfer the wort to the FV at a higher temp and allow the stainless to cool it to pitching temp. Then pitch as soon as possible to get yeast activation started.
Interested to hear anyone else's thoughts or experiences with this and any tips or pointers to help in the future.
Thanks!