lager temperature variations

[barrelboy]

Evening fellow brewers, would appreciate some advice here. Not going into why at this stage but if fermentation temps of a lager were to vary from 10 degrees at night to 15 degrees during the day, each day during fermentation, at these low temps, would it have a detrimental effect on the final outcome.
Cheers BB

[bullfrog]

Temp fluctuations should be avoided as much as possible in any brew. I don't allow variations of anything over +/-2 degrees. That all being said, raising or dropping 5 degrees over a 12 hour period (for arguments sake) doesn't sound all too drastic, I wouldn't have thought.

[emnpaul]

To my relatively inexperienced way of thinking, minor temperature variations might not be such a bad thing with one of the fruitier ale yeasts, but would be undesirable with a cleaner type of yeast such as a lager or US05 ale. However, I haven't had temp variations of over 1.5-2 degrees C while brewing a lager so can't provide a definitive answer, but would be looking for a way to insulate my fermenter such as a doona or old fridge.

Cheers
Paul

[drsmurto]

Lager yeasts at 15C are not good. They will produce esters (and other by products) that will stand out in something as clean as a lager.

If you have anyway of keeping those temps more constant and closer to 10C then its worth the effort.

If you have no way of temp control then as mentioned, ale yeasts in ales or psuedo lagers are far more forgiving.

A consistent fermentation temperature is a big step forward in any brewery.

[DerekMc]

Hi All, This is my first post but have been reading them for a few months now. Also apologise for a slight tangent on this topic but it is the closest I've found. Was after a thread on how to brew down around the 11deg mark. I haven't been that successful with lagers/pils yet. I've done 20 brews with the ales all ok but lagers very average. My fridge seems to control at about 11-12deg with it's thermostat fully clockwise. I was after basic instructions on when to pitch the yeast (do you wait overnight to wort gets to the 11-12deg?) or pitch at say 15 then start to cool. Also at the other end do you allow the brew to warm up to room temp before bottling etc. Also there seems to be a whole science on how much sugar/malt to put in at bottling. Any help appreciated. FYI I've been concentrating on the Cooper's Heritage Lager and the more expensive Munton's Continental Pilsner. NB Don't get on net every day so apologise for late replies.

[Oliver]

Hi Derek, and welcome.

I'm sure I'll be corrected on a few of these things, but here's my take

First and perhaps most importantly, make sure that the yeast you're using is a real lager yeast, because most yeasts that come with "lager" kits aren't lager yeasts, but ale. Coopers Pilsner and I think the Heritage Lager (but not the regular "lager") come with a lager yeast, for instance. If in doubt, ditch the kit yeast and buy a true lager yeast from your HB store.

Pitch a larger-than-usual quantity (i.e. if you were brewing ale) of yeast at about 20C, then drop the temperature to 9-12C. (BTW, 11-12 isn't very cold for a fridge. Are you sure about this?) Make a starter or pitch a couple of sachets of yeast. There are instructions about starters in this thread

In relation to raising the temperature before bottling, what you're referring to is a diacetyl rest. This involves slowly raising the temerature to about 20C after fermentation has finished and holding it there for a few days before reducing it again before bottling. Do a search for diacetyl rest on the forum and you'll find heaps of information.

Someone better qualified than me should be able to comment on the rate of priming, although there have been various threads on the subject so a search will probably answer your questions.

Hope this helps.

Cheers,

Oliver

[DerekMc]

Thanks Oliver

Expanding from original post. The 4 times I've tried this I've first thrown away the supplied yeast and used 2x Saflagers. I pitch them at approx 18deg then drop the temperature down.

I can see that that this diacetyl rest is where I could improve. I've been bottling straight away hence (using 2x drops) I'm getting a fairly gassy brew. When searching for threads I was searching under "brewing at cold Temps". Will try "diacetyl rest" search.

As for the fridge temp I'm pretty confident that's it's the temp (11-12degC) but I must add there is a bit of manual intervention where I turn it off for a couple of hours at a time. (will invest in a temp mate in the future)

So far my futhering of brewing has only been using LDME or a HB Supplied BE2 equivalent, a hops tea bag and use of better yeast sachets. A bit to go before I try yeast starters.

Thanks

[Oliver]

Hi Derek,

Don't let the thought of a yeast starter daunt you. Once you've done it a couple of times it's a breeze!

Cheers,

Oliver

[pendragon8000]

Hi all, I have a few of these ready to go stc-1000 units for sale on ebay:
http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=251177941148
Heres a video:
http://www.youtube.com/watch?v=Mo7zLn7sTBk&feature=plcp
You can leave the fridge and heater plugged in and turn them off independantly with the power point switches on top of the unit.
It has a computer power style socket on the back for power in, this socket has a easily replaceable 10Amp fuse.
At the time of posting this I only have 4 left for sale.
Thanks, happy brewing

[Bum]

Perhaps you could try advertising these at www.aussiehomebrewer.com as well. I'm sure a great many blokes there would be interested in a natter, at the very least.

[Chris2012]

I run an old fridge with a stc-1000 temp controller, which displays temp and has a power socket for heat and cool. So far I've only being brewing ales around the 18C mark, although a few months ago I would get up in the morning early before work and notice the temp down to 13C-15C range.

Do you guys thinks a heating pad to combat this is worth the coin ? and would it make more than a 2% difference to the brew ?

As for temps on fridges, my fermentor fridge is an old girl and I can get it below 2C..