60L fermentor

[calobes]

Hey guys,

A really quick question: is is ok to use a 60L fermentor for regular 23L sized brews?

I have a 60L fermentor but dont want to do a double batch as ive just started brewing.

thanks!

 

[Bribie G]

Works fine, the beer doesn't know how much headspace is above it

 

[calobes]

Thanks bribie. I thought it wouldn't be a problem but wanted to be sure.

Cheers

 

[Greg.L]

Works fine, the beer doesn't know how much headspace is above it

The beer might not know but all the aerobic bacteria and film yeast do know, they love all that extra oxygen. Always keep your headspace as small as possible.

 

[calobes]

The beer might not know but all the aerobic bacteria and film yeast do know, they love all that extra oxygen. Always keep your headspace as small as possible.

Bugger, thought I was all clear
Wouldn't gas build up push out any oxygen before co2?

 

[Greg.L]

Initially the vigorous fermentation produces lots of co2 which pushes out most of the oxygen. Then you have a steep concentration gradient with almost zero oxygen inside and 20% oxygen outside so the oxygen will move inside. Gases can mix in the same volume, law of partial pressures, so the co2 won't protect your beer from oxygen. If you are 100% sure no bugs can get in your fermenter you will be safe, in the real world you can never be sure no matter how good your sanitising. the safe thing to do is keep a small headspace so your beer is as protected as possible. This is standard practise in most of the world. You can go the "she'll be right" route but eventually you will get an infection.

 

[abe max]

I recently got hold of a 60 for free, I threw down a single batch Pacific Ale clone, I just used glad wrap, no air lock.
After a couple of days the wrap had domed nicely, indicating fermentation in full swing, left it for two weeks and bottled.
I put it next to mate's who did the exact same recipe in a standard fermenter, couldn't pick the difference, I'll brew in it again for sure.

 

[calobes]

Thanks for the advice guys. I'll play it safe and save it for when I do a double batch.
This forum is going to be alot of help for me lol

 

[Greg.L]

I recently got hold of a 60 for free, I threw down a single batch Pacific Ale clone, I just used glad wrap, no air lock.
After a couple of days the wrap had domed nicely, indicating fermentation in full swing, left it for two weeks and bottled.
I put it next to mate's who did the exact same recipe in a standard fermenter, couldn't pick the difference, I'll brew in it again for sure.

I guess if it worked once it must be OK.

 

[TheWiggman]

Greg.L, partial pressures and oxygen is a common theme you bring up. You've mentioned the law of partial pressures, but this doesn't explain what you're saying: "The total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual gases in the mixture"
This doesn't say anything about gasses wanting to move through plastic because there's a higher concentration of a gas in one environment than the other. The difference in pressure will determine that. No difference in pressure (after fermentation), no reason for gas to move. Otherwise nitrogen would get in there first due to its higher concentration in the atmosphere.
I could be wrong, but I'd love to see a good reference or evidence of it. I can't find any.
PS: brace up for the snow tomorrow.

 

[SnakeDoctor]

Thanks for the advice guys. I'll play it safe and save it for when I do a double batch.
This forum is going to be alot of help for me lol

People I know very often do single batches in a 60l fermenter, it's no worries at all.

 

[Yob]

I've a shiny new 50l stainless FV for single batch fermenting,

Greg beats this drum a bit without much supporting evidence, certainly not an issue in the norm.

If it was, the infection photo thread would be quite a bit longer

 

[micblair]

Yorkshire squres/rounds are open fermenters - and they don't have any issues with infection.Low pH, hops, alcohol (>3% abv) all safeguard your beer, Besides the beer quickly becomes saturated with CO2, so that rules out all obligate aerobes from harming your beer. She will be right Calobes.

 

[calobes]

Thanks alot everyone. Be prepared for more newb question in the close future

 

[Greg.L]

Greg.L, partial pressures and oxygen is a common theme you bring up. You've mentioned the law of partial pressures, but this doesn't explain what you're saying: "The total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual gases in the mixture"
This doesn't say anything about gasses wanting to move through plastic because there's a higher concentration of a gas in one environment than the other. The difference in pressure will determine that. No difference in pressure (after fermentation), no reason for gas to move. Otherwise nitrogen would get in there first due to its higher concentration in the atmosphere.
I could be wrong, but I'd love to see a good reference or evidence of it. I can't find any.
PS: brace up for the snow tomorrow.

My point is that if a container is full of co2 and not totally sealed, (the situation of a fermenter after the initial fermentation has died down,) the fact that the whole volume is full of co2 doesn't stop oxygen entering. Co2 doesn't have to leave for oxygen to enter, oxygen can get in even as more co2 is being produced. The volume of co2 doesn't affect the oxygen entering. Once it is full no more co2 can get in without increasing the total pressure, but oxygen and Nitrogen can get in without affecting the total pressure, the partial pressures of oxygen and nitrogen will rise but still be less than the partial pressure of co2 so the total pressure will be the pressure of co2.
That is a long winded way of saying that the co2 isn't protecting your beer from oxygen. This science has been known for 200 years.

In terms of brewing it is an established fact that the more oxygen in your headspace, the higher the risk of infection and off flavours. That doesn't mean a big headspace will always cause an infection, it just raises the risk significantly. You can ignore the risk and get away with it for most of the time, especially if your beer is only in the fermenter for 2 weeks. Most gamblers remember the successes more than the failure. Saying " me and my friends do it without problems" is not a scientific approach. If homebrewing is done properly it is a very risk free operation, but I don't think we should be teaching new brewers the most risky methods of fermenting. Personally I don't know why anyone should choose an inferior method when they have gone to a lot of trouble to produce their wort.

 

[Yob]

I dont know about you, often my FV's will keep a positive pressure even after active fermentation has ceased, as seen in the bulging gladwrap lid. My Stout thats in now has well and truly finished and still retains the bulge. I think the time frame we use is to our advantage in this respect, I dont believe it warrants the full tilt danger you attribute to it.

I have to disagree that it's "the most risky" The most risky would, to me, be leaving the frementer open under the lemon tree and mowing the lawn beside it.

Inferior? pffft. Think I'll personally carry on. I dont get many complaints about off flavours in my beers with the methods I employ, inferior methods or not (personal perspective)

While I do have a SSFV now, Im yet to do a side by side of the same wort in a HDPE FV but rest assured that I will (Both will be done with your arch nemesis... Gladwrap lids.. grabs hair and runs screaming to the hills)

 

[TheWiggman]

I know Yob. But as you can see OP has conflicting responses and is being led by Greg's advice as much as yours. If he's right, great, and we've all learnt something. But if not then all it's doing is confusing the matter (again).

My point is that if a container is full of co2 and not totally sealed, (the situation of a fermenter after the initial fermentation has died down,) the fact that the whole volume is full of co2 doesn't stop oxygen entering. Co2 doesn't have to leave for oxygen to enter, oxygen can get in even as more co2 is being produced. The volume of co2 doesn't affect the oxygen entering. Once it is full no more co2 can get in without increasing the total pressure, but oxygen and Nitrogen can get in without affecting the total pressure, the partial pressures of oxygen and nitrogen will rise but still be less than the partial pressure of co2 so the total pressure will be the pressure of co2.
That is a long winded way of saying that the co2 isn't protecting your beer from oxygen. This science has been known for 200 years.

I'd still like to see a good reference or evidence of what you're saying. I'm going to maintain that partial pressures are irrelevent. PROPORTIONS are relevent, who cares about the sum of the pressures of each of the gasses? If there's O2 in there then there's O2 in there. It's not the partial pressures that cause a transfer, it's the absolute pressure.

As far as I'm concerned, the beer won't give two fliers about how much gas is above it, only what's in the gas. I'm as happy to take a breath with 19% O2 in an open field or out of a plastic bag. Same proportion, same effect.

Let's consider your agument though and assume the head space is 100% CO2 and absolute pressure has reached 1 bar (i.e. in equalibrium with the atmosphere). O2 gets in and forms 2% of the head space and is maintained at that proportion.

Is there a difference with 1000l of head space at 2% O2 and 2l of head space at 2% O2? I say no.
CO2 isn't protecting your beer from oxygen? Yes, if there's not a perfect seal.

Head space doesn't matter in the home brewing environment, sealing integrity matters (to a point).

 

[abe max]

I guess if it worked once it must be OK.

I was just sharing my limited experience with a 60 and that I would have no problems brewing in it again, I didn't say it's foolproof

 

[Greg.L]

Some good quotes from sources.

"Gases will always flow from a region of higher partial pressure to one of lower pressure; the larger this difference, the faster the flow. Gases dissolve, diffuse, and react according to their partial pressures, and not necessarily according to their concentrations in a gas mixture."

"The partial pressure of an ideal gas in a mixture is equal to the pressure it would exert if it occupied the same volume alone at the same temperature. This is because ideal gas molecules are so far apart that they don't interfere with each other at all. Actual real-world gases come very close to this ideal."

http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Partial_pressure.html

 

[Bribie G]

Guess Black Sheep and Sam Smith have been doing it all wrong.