ncbrewer
Well-Known Member
I've used Mangrove Jack's yeast four times. Three of these had very slow fermentations (long time to reach stable gravity) – 29, 40, and over 57 days (The last is still fermenting now). They all took off ok and seemed to be doing well, but just kept fermenting longer than expected. No compaints about the beer quality. I've never experienced this with any other yeast. All of these were done with my usual procedure. I started a thread after the first batch - https://www.homebrewtalk.com/forum/threads/fermentation-slow-to-finish.663219/ - at that time it didn't seem to be specific to a particular yeast company, so I started this thread as a different approach.
Extract batch – 8 lbs malt extract
Styles: Marzen, Baltic Porter (lower than normal OG), Belgian Pale Ale
About 5 gallons to fermenter with OG about 1.054
FG: 1.0129, 1.0157, and <1.0061 (still dropping)
Yeast: Mangrove Jack's M54 California Lager, M54, and M47 Belgian Abbey
Yeast was rehydrated at about 80F in boiled and cooled tap water
Used bottling hydrometer with 0.0005 graduations - can easily read to nearest 0.00025
Pitching temp 65F
Active fermentation temp - 67F (four days) for M57 – 70 for M47
Fermentation temp after active – 70F for M57, 74 for M47
Checked hydrometer calibration - good
Gravity numbers are corrected for temperature
(Some of the above numbers vary just a little – I averaged to avoid having a super long post.)
There were several batches with other yeast in between – none of these had slow fermentations.
I emailed Mangrove Jack's after the first problem batch using M57. To skip to the bottom line, the answer was “Our tech team have advised that this is a hybrid strain that is classed as a lager strain regardless of temperature, and the aim is a clean fermentation profile. Therefore, the pitching rate also needs to ensure that the yeast are under the least amount of stress possible. As a result, the lager pitching rate is applied rather than the ale.” This really seems to address the lager profile rather than slow fermentation. And the latest batch used ale yeast. So now I'm wondering if they have a contamination problem - maybe some diastaticus yeast. From what I've read, I believe they repackage yeast from other manufacturers.
Has anyone else had similar experiences or thoughts about this?
Extract batch – 8 lbs malt extract
Styles: Marzen, Baltic Porter (lower than normal OG), Belgian Pale Ale
About 5 gallons to fermenter with OG about 1.054
FG: 1.0129, 1.0157, and <1.0061 (still dropping)
Yeast: Mangrove Jack's M54 California Lager, M54, and M47 Belgian Abbey
Yeast was rehydrated at about 80F in boiled and cooled tap water
Used bottling hydrometer with 0.0005 graduations - can easily read to nearest 0.00025
Pitching temp 65F
Active fermentation temp - 67F (four days) for M57 – 70 for M47
Fermentation temp after active – 70F for M57, 74 for M47
Checked hydrometer calibration - good
Gravity numbers are corrected for temperature
(Some of the above numbers vary just a little – I averaged to avoid having a super long post.)
There were several batches with other yeast in between – none of these had slow fermentations.
I emailed Mangrove Jack's after the first problem batch using M57. To skip to the bottom line, the answer was “Our tech team have advised that this is a hybrid strain that is classed as a lager strain regardless of temperature, and the aim is a clean fermentation profile. Therefore, the pitching rate also needs to ensure that the yeast are under the least amount of stress possible. As a result, the lager pitching rate is applied rather than the ale.” This really seems to address the lager profile rather than slow fermentation. And the latest batch used ale yeast. So now I'm wondering if they have a contamination problem - maybe some diastaticus yeast. From what I've read, I believe they repackage yeast from other manufacturers.
Has anyone else had similar experiences or thoughts about this?
