Suck back on cold crash

[stevonz]

I a cold crash today and I have a blowoff going into a jug of starsan.

A few hours later the jug appears nearly dry... probably about 400ml sucked into the fermenter.

Never had suck back this bad. Stuffed or ok?

I've started using a glycol chiller recently and it crashes the temp very quickly. It's fairly warm here in Brisbane...

 

[wide eyed and legless]

I a cold crash today and I have a blowoff going into a jug of starsan.

A few hours later the jug appears nearly dry... probably about 400ml sucked into the fermenter.

Never had suck back this bad. Stuffed or ok?

I've started using a glycol chiller recently and it crashes the temp very quickly. It's fairly warm here in Brisbane...

I have tried a few things when cold crashing and have gone back to the tried and trusted method of cling wrap over the top of the fermenter. How much air gets pulled into the fermenter, anecdotal evidence for me suggests none. Only because I haven't had an oxidised beer bar one which was almost 3 years old.

 

[yankinoz]

I have tried a few things when cold crashing and have gone back to the tried and trusted method of cling wrap over the top of the fermenter. How much air gets pulled into the fermenter, anecdotal evidence for me suggests none. Only because I haven't had an oxidised beer bar one which was almost 3 years old.

If outside air did not enter your system, at the least the cling wrap would bulge downward into the fermenter. Is it doing so? If not, outside air is entering. I'm assuming you don't add CO2.

 

[stevonz]

I have tried a few things when cold crashing and have gone back to the tried and trusted method of cling wrap over the top of the fermenter. How much air gets pulled into the fermenter, anecdotal evidence for me suggests none. Only because I haven't had an oxidised beer bar one which was almost 3 years old.

What do you think about the current batch though? Is it drinkable?

 

[wide eyed and legless]

What do you think about the current batch though? Is it drinkable?

Well it isn't going to harm you, I presume it is 21 litres? I'm not sure if it will have any effect on the taste.

If outside air did not enter your system, at the least the cling wrap would bulge downward into the fermenter. Is it doing so? If not, outside air is entering. I'm assuming you don't add CO2.

Well 21 litres in a 30 litre fermenter so I have 9 litres of CO2 in the head space once the pressures equalise at 100 kPa. There is very little resistance offered by the cling wrap, the CO2 vents easy enough through it while fermentation is in progress. So as a vacuum takes effect by the CO2 dissolving into the beer during cold crash air will infiltrate the cling wrap covering but I believe it doesn't enter the beer. It just replaces the CO2 taken up by the cooling beer.
This is really the same thing most home brewers did before the introduction of closed vessel fermenters. Now if air was getting into the beer prior to the I have never seen anyone writing posts about it on all the forums I have been on.
We see some folk giving a squirt of CO2 into the above CVF's putting a positive pressure in them prior to cold crashing so the fermenter doesn't collapse from the vacuum. Also the balloons filled with fermenting gas to be drawn in through the forming vacuum. I have tried both, even accidentally leaving the lid on the Apollo and the fermenter has buckled but but not damaged it.
While it is wise to try to eliminate any oxygen ingress I do think that there is too much overthinking the cold crashing.

 

[fifis101]

It was common back in the day to just cover an open bucket with a tea towel! I think you are right WEAL about people overthinking it these days. If you are worried, I think the balloon method is the best option.

 

[stevonz]

I had a taste - seems alright actually. Kegged & will see how it goes next week.
Dropped another batch into fermenter... just gotta remember to change process when cold-crashing!

 

[Vince Burns]

It doesn't matter if the air gets in and dissolves in the cooling wort. Oxygen is fine at this point. In fact, this is when you oxygenate the wort so there is enough for the yeast to grow. What you want to exclude is any micro-organisms. Once oxygen has been added you then add the yeast and put an air-lock on. It is from this point onwards you want to keep air excluded because it will spoil the finished beer.

The solubility of oxygen in water isn't very high, and the boil removes it all. That's why you need to add it once it has cooled. In fact, it is so low that any added oxygen is used by the yeast as the yeast multiplies in the first few days of fermentation (during the lag phase). From this point on any contact with oxygen will allow specific off-flavours to develop so you need to be anal about excluding air, but not at the point you are describing.

Hope this helps.

 

[wide eyed and legless]

It doesn't matter if the air gets in and dissolves in the cooling wort. Oxygen is fine at this point. In fact, this is when you oxygenate the wort so there is enough for the yeast to grow. What you want to exclude is any micro-organisms. Once oxygen has been added you then add the yeast and put an air-lock on. It is from this point onwards you want to keep air excluded because it will spoil the finished beer.

The solubility of oxygen in water isn't very high, and the boil removes it all. That's why you need to add it once it has cooled. In fact, it is so low that any added oxygen is used by the yeast as the yeast multiplies in the first few days of fermentation (during the lag phase). From this point on any contact with oxygen will allow specific off-flavours to develop so you need to be anal about excluding air, but not at the point you are describing.

Hope this helps.

It is after fermentation has finished the OP is querying.

 

[TwoCrows]

I have heard that coke-cola use starsan thru-out their product process. They use it to sanitize and lower ph.

If mixed correctly at 1.5 ml per litre. 400 ml is not that much to worry about in 20 ish litres. I would not be too happy that it happened, although I would try it and probably drink all of it. It is home brew and I have heard of worse things that have happened that people would consume.