Friday, July 17, 2009

Lager is imminent

Crap! It's been a week since I posted last. I've been busy and just too lazy to write anything.

But, I have some news. A little less than a year ago, I got an old spare fridge for with which to lager beers. It didn't survive the move. The coldest I could get it was ambient temperature.

Well, I am pleased to report that I moved another fridge into my garage and IT WORKS!!!! (I was going to show pictures, but I'm not sure where my camera is. If anyone knows, please tell me).

I have not used it for beer brewing yet, but I did use it to chill some beer.

I still needed a temperature control device. Normal fridge temperatures are too cold for lagering. That has to be done anywhere from 40-55°F. So, I went on the eBay and found me this:

I need to add the power cable to it. I have an extension cord I will cut in half and wire it to and from the temperature controller. The fridge is set to its lowest setting, the temperature probe is put inside the fridge and the ETC cycles the power on or off as necessary to maintain the temperature. I plan on starting my first legit lager on Sunday.


the iNDefatigable mjenks said...

Hey, that's pretty cool. If it works, let me know, and I'll clue my Optometrist buddy in on it. He's bitched forever about getting that diacetyl butterscotch flavor in his stuff, and I'm wondering if keeping the yeast cooler would help.

Chemgeek said...

Lot of people do a diacetyl rest in which they allow the fermenter to warm to room temp for a few days. Apparently, this helps dispel some of the diacetyl.

Lisa-tastrophies said...

Ok, no idea what you and Mjenks are talking about, but I'll help you with the post-production lager removal if needed :-)

Alex Topfer said...

Diacetyl is produced by the yeast when the fermentation temperature is too low. From memory it's a precursor to alcohol, so my guess is that the whatever -> diacetyl steps happens faster than the diacetyl -> alcohol at low temps.
Doing a diacetyl rest gives the yeast a chance to mop up the diacetyl (a long secondary might also work).

Schlafly Beer said...

If you ferment your beer as close to its ideal temperature you will minimize the production of diacetyl (the ideal temp depending on the strain of yeast you use. Usually upper 60's for most ales and low 50's for most lagers).

After the beer has hit its terminal gravity, allowing it to warm up a few degrees (say 5 deg for an ale, 10 deg for a lager) can help the yeast reabsorb the diacetyl. It's especially important for lagers.

You can also agitate your carboy to get the yeast back in suspension. Greater contact time will help the yeast reabsorb it.

The key is to wait until the diacetyl has been reabsorbed before you crash-cool your beer. If you don't: butter beer.

A quick sensory test is to take a sample (2-3 oz), warm it up in hot water (180 deg for 20 min) and then chill it in ice water. Pour the beer into a goblet or other glass that will help intensify the aroma. The process will intensify any diacetyl aroma that is present.

A good rule of thumb is to test 7-10 days from the brewdate for ales, 10+ days for lagers.

Remember warmer fermentation = more yeast growth = more diacetyl. The diacetyl is a biproduct of the yeast's production of amino acids necessary for cell growth.

Lacto and pedio can also cause a similar off flavor in beer, but that's another matter.

- A brewer

Aaron said...

I've been itching to get one of those temperature controllers, have yet to make a true lager.

Chemgeek said...

Aaron, it is awesome. I have not sampled the beer yet, but the temp controller is awesome.