Ferment Temp, Ambient vs Internal

Discussion in 'General Brewing Discussions' started by MrBIP, Jun 9, 2015.

  1. MrBIP

    MrBIP Active Member

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    Temp Controller arrived yesterday and picking up fridge Thursday.
    I've kept very good records of ambient temps that turned out best with the several beers I've been making, so plan to reference those notes for those beers, however ......

    At some point in the near future, I'm going to want to try a true lager; from all I've read, I think I'd be ok to make the wort, put it in the fridge at, say 6 degrees (?), lower than what I really want (and I'll target the low end of the yeast range), let it cool overnight. Yeast starter with it. Then pitch the yeast the next morning.

    I already understand building a bigger starter, getting the diacetyl rest, gradually reducing temp for the lagering phase, etc. But hoping to confirm ok on the 6 degree differential with a lager and ok to let it sit overnight to acclimate to the ferment fridge temp before pitching yeast. (There is no way I'll be able to the wort cold enough with the wort chiller).

    Thanks in advance,
    MrBIP
     
  2. Ozarks Mountain Brew

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    as for Ambient vs Internal, in my experience depending on the yeast and temperature, the wort can reach as high as 7 degrees above air temperature so i just set the air on my system lower than you might think, 54 to 60 , then after 5 days raise it up to 65 air temp , it equalizes out to be the same temp for inside wort and air, as for a lager just go as low as you can and call it good for your first, it should be fine, worst case you get some add flavors then you learn lol
     
  3. jeffpn

    jeffpn Well-Known Member

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    I use the same tubing as I used for my counterflow chiller. I pinched and soldered one end to make a well, and it sits in the beer in the carboy. My temperature probe is in that tube. That way, I don't have to guess at what the beer temperature is relative to ambient temperature. In theory, the beer itself is the temp set on the controller, not the air around it.
     
  4. Ozarks Mountain Brew

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    I have a 8" weldless thermal well through the lid of my carboy, then I drop my 10" rtd probe inside and read it with a display right next to my air temp display
     

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  5. MrBIP

    MrBIP Active Member

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    Yes, it would make more sense to just go get the thermal well .. one step at a time.
    Sounds like 6 degrees is probably a good starting point.
    And I'm sure if I keeping things clean, putting wort and yeast in fridge to acclimate overnight before pitching should not be an issue.

    Thanks,
     
  6. GernBlanston

    GernBlanston New Member

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    I always place my fermenter, and starter, in the chamber overnight to chill to about 48F, then pitch the next day. No problem with this method, assuming care has been taken to keep the process clean. I use the Jamil Z method of chilling to the low end of the yeast range, and pitch yeast of the same temp, then after a day or two, if there is no visible sign of fermentation, I may bump it up a few degrees. Then after fermentation has taken off, and it seems that it is slowing down, I will start ramping up the temp a few degrees a day, just to keep the yeast working hard. I only raise it 10 to 15 degrees from the pitching temp.

    If this is your first lager, then remember to be patient. It might take a week for fermentation to reach high krausen, as it is working at colder temps. This is normal.

    If you pitch at the cold end of the yeast range and wait for post high krausen to ramp up the temperature.
    You may not need a diacetyl rest. Taste the beer, if it tastes diacetyl free, then your good.

    Don't be in a hurry to get it off the yeast. Leave it in the primary for at least a month, then slowly ramp down to lager temps and leave it there for another week or two before kegging or transferring to a secondary for the lagering faze. The reason you are using this yeast and these methods, is to produce a beer with the clean, crisp, ester free character common in lager beer. Don't short cut the ability of the yeast to do its job.

    As for the 6 degree of separation question, all I can say is that I tape the probe to the carboy with some insulation, and set my temp controller to 48F. There is some natural movement inside the fermenter with yeast activity and temperature variants that the beer will churn itself some. Enough to balance out the temps? Maybe. What is important is that you try it, and if you think your temps were 6 degrees too high then next batch change your process until your satisfied. Remember, its the yeast that makes the beer, not you. All we can do is give the yeast the proper environment and tools to work.
     

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