Cold Crashing

[verysupple]

There are generally two schools of thought on step 3. Bribie is right in that lager yeast will work at 4 C. But only if there's any work to be done. If the beer is at FG and the yeast has already cleaned up the diacetyl, acetaldehyde etc. then there's nothing left for them to do, so you can crash it quickly. If you take a more traditional approach where you start lowering the temp before reaching FG, then you have to lower the temp slowly so the yeast stay active and can finish the job.

With your method the yeast have done everything they need to so you can just crash it. For more detail check this out.

EDIT: BTW, because with your method the yeast has already done all the work before you lower it to 4 C, there's actually no point doing the stop at 4C and you might as well go straight to -1 C.

 

[Black n Tan]

very supple is spot on. Yes lager yeast will clean up at 4C but only if the temp is lowered slowly so as not to shock the yeast into dormancy. I perform an extended diacetyl rest so all my clean up is already done (much like you have done), so I crash quickly to -1C to precipitate protein and tannins, and skip the 4C lagering. The braukaiser link verysupple provided has a wealth of information about the different options: I get good results with something similar to option f.

 

[ralphstralph]

can you cold crash all styles of beers eg ipa or will it take out all its nice colours also does it do anything to the flavours of the hops that got added during the boil ?

 

[verysupple]

Yes, you can cold crash any style. It will not affect colour (although the improved clarity may give that impression). If you cold crash for only a few days it won't change the flavour (other than dropping out the particulate, which is good). If you cold crash for a long time, like if you lager for a number of weeks or up to months, then it may have some effect on the flavour by precipitating polyphenols and the like and will make the beer more mellow/smooth. But mostly people cold crash ales for a few days to a week just to drop the yeast and other crud and it doesn't really affect hoppiness, if that's what you're worried about.

 

[Dazzbrew]

When cold crashing do you need to remove the blow off tube from the cup of sanitiser or do anything with the airlock?

 

[indica86]

When cold crashing do you need to remove the blow off tube from the cup of sanitiser or do anything with the airlock?

What is an airlock?

 

[Lowlyf]

When cold crashing do you need to remove the blow off tube from the cup of sanitiser or do anything with the airlock?

I searched this thread purely for this question. Does anyone have an answer? I'm cold crashing as we speak and I still have the airlock in...

 

[troopa]

If the solution from the airlock is getting sucked into the fermenter then yes.. if its not then no.

 

[Lowlyf]

If the solution from the airlock is getting sucked into the fermenter then yes.. if its not then no.

I'm not sitting in front of the fridge watching it haha. I guess I'll need to check it from time to time

 

[Grott]

If you want to play safe, loosen the lid a bit.
Cheers

 

[Rocker1986]

I went to pick up some bottles from a bloke a couple of years ago. When I was there he was preparing a couple of FV's for cold crashing. He removed the airlocks, and simply put some duct tape over the holes in the lids. This could be an option too, and you don't have to worry about suck back at all.

I actually use my FV like this all the way through fermentation, since the grommet broke and I couldn't be arsed buying a new one. :lol:

 

[troopa]

OT I personally hadn't used an airlock for nearly 5 years.. I decided to do a mead in a 5L demi the other week and chucked an airlock for the hell of it.
I spent the next 5 days staring at the bloody thing bubbling away. It was great. Bloop Bloop Bloop
Racked to secondary and chucked some glad wrap over the top of it.... Now i have 10mins a day of my life back


Troopa