Help with fermenting a lager

[AHagne]

Hi all!
Friday evening i brewed a lager

Pilsner malt 60%
Flaked corn 40%
OG 1.049
Yeast: Fermentis S-189

I put it in my fermentation chamber which is controlled with an ITC-308, i had already tried out the chamber with a fermenter with water to see if the ITC-308 deviated from "actual temp" which was measured with a thermometer in direct contact with water. When i did this "actual" temp was 1C lower than what the ITC showed. The ITC-308 probe is insulated on the outside of the fermenter.

I set the ITC-308 to 12C and when i decided to measure SG today the temperature was 14C and SG 1.041. I would like the fermentation temperature to be as low as possible, preferably as low as low as 10C. Can i set my fermentation chamber to achieve this now or would this "ruin" the beer? I will add a diacetyl rest at the end of the fermentation period.

 

[helibrewer]

You can lower it, just go slowly, a degree every couple of hours, it will take a while to cool the entire mass. What type of fermenter are you using? Ideally you want a probe in a thermowell instead of on the outside of the fermenter.

 

[AHagne]

You can lower it, just go slowly, a degree every couple of hours, it will take a while to cool the entire mass. What type of fermenter are you using? Ideally you want a probe in a thermowell instead of on the outside of the fermenter.

Thanks, i'll do that, and this will not produce any off flavors? Or have the possible off flavors already been produced and will be taken care of the diacetyl rest i'm planning on at the end of the fermentation?
I'm using a bucket fermenter, yeah i will probably arrange some sort of solution to get a more precise reading in the future. I thought my test with water would give me a good indication of what i could put the ITC at to achieve the temperature i wanted.

 

[helibrewer]

Thanks, i'll do that, and this will not produce any off flavors? Or have the possible off flavors already been produced and will be taken care of the diacetyl rest i'm planning on at the end of the fermentation?
I'm using a bucket fermenter, yeah i will probably arrange some sort of solution to get a more precise reading in the future. I thought my test with water would give me a good indication of what i could put the ITC at to achieve the temperature i wanted.

I don't think off flavors are too much of a concern. For a bucket you can use a 2-hole number 10 stopper with a long thermowell in one of the holes, just cut the appropriate size hole in your lid. Water is always a good test but fermentation is exothermal so the comparison is not exact.

 

[AHagne]

I don't think off flavors are too much of a concern. For a bucket you can use a 2-hole number 10 stopper with a long thermowell in one of the holes, just cut the appropriate size hole in your lid. Water is always a good test but fermentation is exothermal so the comparison is not exact.

Yeah i've experienced this now, luckily i caught it quite early so i can do something about it. Sounds like a good idea! Never read much on thermowells but i suppose they conduct heat well enough that there are no/very little temperature error when the probe is sitting in there?

 

[helibrewer]

Yeah i've experienced this now, luckily i caught it quite early so i can do something about it. Sounds like a good idea! Never read much on thermowells but i suppose they conduct heat well enough that there are no/very little temperature error when the probe is sitting in there?

Yes, you can put a couple ml's of water or mineral oil in them to help with heat transfer.

 

[AHagne]

Yes, you can put a couple ml's of water or mineral oil in them to help with heat transfer.

Great! Will try this, if this is not to my liking i'll get the 12" probe from Ink-Bird