yo-yoing lager temperatures. What can I expect from this beer?

[Cro Magnon]

I decided to attempt my first lager (BIAB). Just a clean pilsner - 100% pilsner malt and saaz, that's it. Saflager W 34/70.

I have no fancy equipment whatsoever. Really elementary setup of putting the fermenter in a wide bucket filled with water, replacing frozen PET bottles to keep it cold.

Thing is, I didn't realise just how often I'd need to replace the PET bottles. It comes down to about 12-14 C and then rises to between 18-19C in a matter of like half an hour (unless my thermometer is wrong). So yeah....it's been fermenting 3 days so far at between 13-19C (yes yes amateur I know )

So basically what can I expect this to taste like? Is there any risk of a stalled fermentation? Any tips on how to regulate the temperature better with this basic setup?

Note: I didn't take any hydrometer readings as I do small batches and this was half of my regular small batch (about 4 litres)....just an experiment basically.

I was so excited about brewing lagers...bought a whole bunch of malts...and this has been such a pain and can't imagine doing another one.

 

[VikeMan]

I wouldn't be too worried about a stalled fermentation. It's even likely you had a faster than normal fermentation. But if you were hitting 19C early in fermentation, you might expect higher than normal levels of esters. OTOH, Fermentis claims incredibly even performance across a wide temperature range for 34/70.

 

[Sammy86]

You should be ok, 34/70 is known to be a very forgiving lager yeast. I routinely ferment with 34/70 at 62-64° and dont have issues. Let it ride!

 

[Cro Magnon]

You should be ok, 34/70 is known to be a very forgiving lager yeast. I routinely ferment with 34/70 at 62-64° and dont have issues. Let it ride!

Great to know! Hopefully it forgives me and the beer doesn't exact a yo-yoing revenge upon me.

 

[Cro Magnon]

I wouldn't be too worried about a stalled fermentation. It's even likely you had a faster than normal fermentation. But if you were hitting 19C early in fermentation, you might expect higher than normal levels of esters. OTOH, Fermentis claims incredibly even performance across a wide temperature range for 34/70.

Oh that's great....well it's an experiment for me anyway..I'll make a note of all the off flavours if any...Hopefully the esters will surprise me!

 

[McKnuckle]

Just keep in mind, since you are excited, that lagers really benefit from aging, even modestly. After fermentation and D-rest are complete, and carbonating warm (if you are doing that), let it spend an absolute minimum of 2 weeks cold before even sniffing around it. Week 3 will be another big jump in quality, with things settling into a long term groove at week 4.

From there, if it's not already clear and clean, it will continue to improve at a much slower rate for another couple/few months.

Rushing the conditioning/cold storage phase of lagers is rarely worthwhile.

 

[Cro Magnon]

Just keep in mind, since you are excited, that lagers really benefit from aging, even modestly. After fermentation and D-rest are complete, and carbonating warm (if you are doing that), let it spend an absolute minimum of 2 weeks cold before even sniffing around it. Week 3 will be another big jump in quality, with things settling into a long term groove at week 4.

From there, if it's not already clear and clean, it will continue to improve at a much slower rate for another couple/few months.

Rushing the conditioning/cold storage phase of lagers is rarely worthwhile.

Thanks for the encouragement! I definitely planned to lager for at least 4 weeks. After that will keep a few bottles for a while longer to experiment. It's the fermentation phase that's a problem for me cos I can't control the temperature too well. However if the lagering makes up for some of the flavour imbalances that would be great.

 

[Cro Magnon]

Just keep in mind, since you are excited, that lagers really benefit from aging, even modestly. After fermentation and D-rest are complete, and carbonating warm (if you are doing that), let it spend an absolute minimum of 2 weeks cold before even sniffing around it. Week 3 will be another big jump in quality, with things settling into a long term groove at week 4.

From there, if it's not already clear and clean, it will continue to improve at a much slower rate for another couple/few months.

Rushing the conditioning/cold storage phase of lagers is rarely worthwhile.

BTW @McKnuckle .....how do I know if there's enough health yeast before I carbonate....or if I need to repitch?

 

[McKnuckle]

You shouldn't have to worry at all about pitching more yeast. That's only a factor after either extended aging or a high ABV. Go with what you've got!

 

[dmtaylor]

It will turn out just fine. W-34/70 is a very forgiving yeast. You could ferment at 19C the entire time and it would be good.

 

[Cro Magnon]

Thanks! @McKnuckle That's good!

@dmtaylor That's great to know as well. Should be good then...managed to keep it averaging at 16 C I would say..

 

[madscientist451]

Before I obtained a chest freezer, I used a 24" x 24" cardboard box with 1" foam insulation on the inside and sealed on the inside with duct tape. 1 and 2 liter frozen water bottles fit in the corners of the box with the carboy in there. I kept the box in my chilly basement and I could easily maintain 10 degrees F below ambient temperature by changing the water bottles every day. I could adjust the temperature by using more or less ice and changing it out more frequently or less.
I fermented lagers like this for several years and they came out pretty good.
There are several you tube videos showing DIY fermentation chambers with insulation board and ice.

 

[Cro Magnon]

Before I obtained a chest freezer, I used a 24" x 24" cardboard box with 1" foam insulation on the inside and sealed on the inside with duct tape. 1 and 2 liter frozen water bottles fit in the corners of the box with the carboy in there. I kept the box in my chilly basement and I could easily maintain 10 degrees F below ambient temperature by changing the water bottles every day. I could adjust the temperature by using more or less ice and changing it out more frequently or less.
I fermented lagers like this for several years and they came out pretty good.
There are several you tube videos showing DIY fermentation chambers with insulation board and ice.

Thanks a lot for sharing the info....Did you fix the insulation yourself or is it some kind of box that came with insulation. Nonetheless will check out the DIY videos. I suppose if it's covered it would make a huge difference...The bucket i'm using is just open so obviously I lose (or gain rather) temperature really quick...I suppose some sort of igloo type cooler,if it's big enough would do the job...