Cold Crash Question. Pre- vs post-carbonation

[agentbud]

Normally when I finish fermenting a beer, I transfer it to keg, hook it up to a CO2 tank and put it in the fridge. After a few days it is carbonated and I draw off a couple of glasses to remove any sediment that has settled out to the bottom. Is this process any different from cold crashing in the fermenter prior to transferring to keg and carbonating? In other words, is there any difference in cold crashing pre-carbonation vs post-carbonation?

 

[VikeMan]

IMO, the most important difference is that when you cold crash in a fermenter, you need a way to prevent suck-back of O2 due to the pressure change.

 

[postalbunny]

Pretty much the same diff... your just "cold crashing" in the keg. If you cold crash in fermenter then you can transfer off 5g of "clear" beer but you risk introducing o2 if you don't have a way to mitigate that (pressurized fermenter, spunding, etc).

if you transfer without cold crashing you get some sediment that will settle out. you won't usually lose more than a few pints. There is also a risk of clogging transfer tubing or fittings if you have a heavy adjunct or dry hopped beer.

A lot of people brew "6.5g" batches because they lose 1/2 to 1g of wort in transfer into the fermenter making 5.5g. Then they lose .5g to trub after cold crashing... leaving with a perfectly full 5g keg. Conversely, some people could care less about getting that batch size perfect and brew 5g batches on the stove then dump the whole pot in the fermenter. After transfering they may end up with only get 4-4.5g of clear drinkable beer.

 

[agentbud]

Pretty much the same diff... your just "cold crashing" in the keg. If you cold crash in fermenter then you can transfer off 5g of "clear" beer but you risk introducing o2 if you don't have a way to mitigate that (pressurized fermenter, spunding, etc).

if you transfer without cold crashing you get some sediment that will settle out. you won't usually lose more than a few pints. There is also a risk of clogging transfer tubing or fittings if you have a heavy adjunct or dry hopped beer.

A lot of people brew "6.5g" batches because they lose 1/2 to 1g of wort in transfer into the fermenter making 5.5g. Then they lose .5g to trub after cold crashing... leaving with a perfectly full 5g keg. Conversely, some people could care less about getting that batch size perfect and brew 5g batches on the stove then dump the whole pot in the fermenter. After transfering they may end up with only get 4-4.5g of clear drinkable beer.

So carbonation does NOT affect what happens during cold crash then, correct? All, or most anyway, of the hop/yeast material will drop out during cold crash exactly the same regardless of whether it has been carbonated or not, right?

 

[McKnuckle]

That's right. Carbonation has no effect on settling and conditioning. Might as well do it all at the same time.

 

[agentbud]

That's right. Carbonation has no effect on settling and conditioning. Might as well do it all at the same time.

Thanks

 

[Jordan Logo]

What they said ^^^

My $0.02 is that it'll depend on how much initial trub your fermentor is showing before you cold crash, AND if you're racking from the top vs through a spigot at the bottom of the fermentor.

Stay with me here.... I ferment in a regular old bucket with a spigot on the bottom. Before I got a proper BIAB bag, and hop spider/bag I used to get a sh*t ton of trub on the bottom of my bucket that would cover my spigot causing the first pours of my keg to be cloudy and "off tasting." Now that I don't have that bag problem, I get very minimal trub at the bottom of my buckets, and as of my last brew, I got a solid yeast cake, no hop debris or left over malt particles (at least to the naked eye).

If you were to cold crash and transfer to a keg with a whole bunch of trub covering your spigot, you're obviously going to get a sh*t ton of debris in your keg - if you you don't you should be good. I'd suggest checking your system and seeing if there might be a flaw in your bag not being up to par, or if there is some way "more than necessary" particles are getting into your fermentor.

A few tips:

1. Get a good quality BIAB bag/hop bag - "wilserbrewer BIAB Bags" makes the best on the market
2. Use "wilserbrewer BIAB Bags" as a filter, or something that will upgrade your system, as you transfer to your boil kettle, and or your fermentor
3. When you chill your wort, right about when your like 10-20 mins away from hitting your target chill temp, stir your chilling wort like a damn mad man - this will cause all the particles in the kettle to settle towards the center of your kettle
4. Calculate into your losses to where you don't have to tilt your kettle to get your batch volume into your fermentor. For example: for my kettle, if I don't tip it I'll loose exactly 1 gallon of beer (which 90% is already trub).

 

[agentbud]

What they said ^^^

My $0.02 is that it'll depend on how much initial trub your fermentor is showing before you cold crash, AND if you're racking from the top vs through a spigot at the bottom of the fermentor.

Stay with me here.... I ferment in a regular old bucket with a spigot on the bottom. Before I got a proper BIAB bag, and hop spider/bag I used to get a sh*t ton of trub on the bottom of my bucket that would cover my spigot causing the first pours of my keg to be cloudy and "off tasting." Now that I don't have that bag problem, I get very minimal trub at the bottom of my buckets, and as of my last brew, I got a solid yeast cake, no hop debris or left over malt particles (at least to the naked eye).

If you were to cold crash and transfer to a keg with a whole bunch of trub covering your spigot, you're obviously going to get a sh*t ton of debris in your keg - if you you don't you should be good. I'd suggest checking your system and seeing if there might be a flaw in your bag not being up to par, or if there is some way "more than necessary" particles are getting into your fermentor.

A few tips:

1. Get a good quality BIAB bag/hop bag - "wilserbrewer BIAB Bags" makes the best on the market
2. Use "wilserbrewer BIAB Bags" as a filter, or something that will upgrade your system, as you transfer to your boil kettle, and or your fermentor
3. When you chill your wort, right about when your like 10-20 mins away from hitting your target chill temp, stir your chilling wort like a damn mad man - this will cause all the particles in the kettle to settle towards the center of your kettle
4. Calculate into your losses to where you don't have to tilt your kettle to get your batch volume into your fermentor. For example: for my kettle, if I don't tip it I'll loose exactly 1 gallon of beer (which 90% is already trub).

Great info, thanks. I am now fermenting in a brewtech brew bucket which has a rotating racking arm so I was able to avoid the trub at the bottom. Current brew was heavily dry-hopped so even though the hops were in a bag, there was still material floating (in suspension) but not enough to be concerned about clogs. I probably was not clear in my original message but my main reason for this post was that I had never "cold crashed" before but I do keg my beer and wanted to make sure that kegging and carbonating the beer and letting it sit in the fridge a few days was serving the same purpose as cold crashing in the fermenter prior to kegging. (ie - does carbonation affect cold crashing). From the responses so far, it sounds like it does do the exact same thing (other than having to draw off a couple glasses of sediment before drinking). I appreciate everyone's info.

 

[str1p3s]

I stopped cold crashing in the fermenter because of oxygen issues. I move it to the keg when it's done bubbling, leave it at ferm temps for a few days in the keg, then hook it up to co2 and bring it down to the 30s so I can force carb. I also bought a floating dip tube so I can get clear beer faster without wasting the first few pints. I'm extremely happy with the results since changing to this process!

 

[LittleRiver]

...is there any difference in cold crashing pre-carbonation vs post-carbonation?

They both work, the only difference is in where the sediment ends up. I cold crash in the fermenter because I want as much sediment as possible to stay there, and not be transferred to my keg.

Dealing with suck back during a fermenter cold crash is easy. Just rig up a mylar balloon. Keep the tube going to the empty balloon clamped off for the first couple of days of active fermentation. That will give time for the yeast to purge the headspace in the fermenter. You want the balloon to fill with fermentation gas, not air.

I have a second line coming from the top of my fermenter that goes to the beer post of a cleaned & sanitized keg. An airlock goes on the gas post. Fermentation produces enough volume to very effectively purge the keg.

During cold crashing gas is pulled from the balloon. There is more resistance from the airlock, so it won't pull from there.

To do a closed transfer, connect the hose from the top of the fermenter to the keg gas post, and connect the spigot at the bottom of the fermenter to the keg beer post. I use a little inline filter in that hose, and thoroughly purge the hose/filter with C02 before connecting it.

 

[agentbud]

I stopped cold crashing in the fermenter because of oxygen issues. I move it to the keg when it's done bubbling, leave it at ferm temps for a few days in the keg, then hook it up to co2 and bring it down to the 30s so I can force carb. I also bought a floating dip tube so I can get clear beer faster without wasting the first few pints. I'm extremely happy with the results since changing to this process!

I have a floating dip tube on my to-buy list. Looking at the Torpedo one. What brand do you have and does it work as advertised?

 

[McKnuckle]

This from Willam's Brewing costs $18 and works a treat. No need for anything fancier in my experience.