Putting the Batch in the Fridge

[ben2904]

I have an uncle that used to brew beer and he told me before I siphon my beer to secondary/bottling, I should put the 5 gallon bucket in the fridge for couple of hours so the trub will sink and I'll get much more clear beer.
Is that true? What do you think about it?

 

[Calichusetts]

Its called cold crashing and speeds up the dropping out of yeast and gets you better clarity. It will (in most cases) compact and harden the trub for easier siphoning. I almost always do it, for days though, not hours

 

[ben2904]

Its called cold crashing and speeds up the dropping out of yeast and gets you better clarity. It will (in most cases) compact and harden the trub for easier siphoning. I almost always do it, for days though, not hours

how many days? and it stops the fermantation during that time right? so after I finish the fermantation I do that?

 

[Calichusetts]

Yes...after you are SURE fermentation is done. I will crash for 2-4 days, depending on the clarity already. Some people go a week but I don't think you need to do more.

You can bottle cold as well, just carbonate at the 70ish temp mark. I usually move the carboy out of the fridge to where I bottle the night before. Everything stirred up resettles and a few hours solves that.

 

[GarageDweller]

cold crash. below 45°f. do it. 2 days is plenty. good luck. cheers.

 

[Rosenhops]

you want to make sure your yeast have reabsorbed the diacetyl. cold crashing too early can make a beer undesirably buttery. easy way to check, take a sample (like a 1/2 cup so it's quick) and boil it. the precursors to the diacetyl (which the yeast should reabsorb) will oxidize and become diacetyl. tasting or smelling it will tell you quickly and easily whether you're good to cool or not.

 

[ben2904]

you want to make sure your yeast have reabsorbed the diacetyl. cold crashing too early can make a beer undesirably buttery. easy way to check, take a sample (like a 1/2 cup so it's quick) and boil it. the precursors to the diacetyl (which the yeast should reabsorb) will oxidize and become diacetyl. tasting or smelling it will tell you quickly and easily whether you're good to cool or not.

any simple explanation?

 

[Calichusetts]

any simple explanation?

He's talking about lagers and a good D-rest will avoid that procedure. Just make sure fermentation is complete with a hydrometer check over a few days.

 

[BigFloyd]

any simple explanation?

Sure. When fermenting an ale, pitch and keep the temp at the low end (typically 63-64*F) of what is "optimal" for the yeast being used for 4-5 days, then let it come up on its own closer to the high end of optimal (say, 68*F). That will help the yeast clean up the ordinary by-products of fermentation (including diacetyl).

Ale yeasts can and do produce some diacetyl. Some, like 1968ESB and WLP002 are known for it. The reason that it's more necessary to give a lager ferment a "d-rest" (like at 61-62*F) is that bumping the temp into the low-60's allows the diacetyl precursors to chemically convert to actual diacetyl that the lager yeast can then consume.

BTW, if you cold crash a batch in the primary (I do 5-7 days at 35*F), skip the secondary. Unless you're dry hopping or adding fruit, you don't need it. A few hours in the fridge isn't even enough time for the 5 gallons to cool down.

 

[Rosenhops]

Even if the SG has gone down to a finished value any yeast in suspension still maintain the ability to reabsorb byproducts and by products may still be there (ie: there is still a lot of work occuring after fermenting and before settling). The question really is all about those byproducts as far as cold crashing goes and its such an easy test. I've surprised myself a few times when checking and thinking it was finished (I cold crash all my beers).