Pressure from Fermentation

[StevenD55]

Ideal gas law aside, does anyone know just how much CO2 pressure can be generated from the yeast fermentation? I've seen calculations on volume of CO2 generated by fermentation. But, nothing yet as to the potential pressure buildup.

Sort of curious after a canning jar of dark grape juice exploded resulting in the need to repaint a room.

 

[JohnT]

I have seen pressure soar well above 80psi. I always use gloves and eye protection whenever I handle champagne.

 

[StevenD55]

Thanks for the info

 

[richmke]

A starting SG of 1.120 has about 39 ounces of sugar per gallon.
For 6 gallons, that is about 470 ounces of sugar
470 ounces of sugar is about 38.75 moles of sugar
38.77 moles of sugar, fermented, produces about 950 liters of CO2 gas at 1 atmosphere and 25 degrees centigrade.

The pressure then depends upon how much you want to compress the 950 liters of gas. Note: a lot of the CO2 will stay in solution and not contribute to the pressure.

 

[Troll]

I am not sure of the pressure but had a bottle of root beer blow up a capped coke bottle. It blew the majority of the 16oz bottle through the drywall ceiling above. If pressure don't affect the yeast gas pressure could reach 80psi

 

[sour_grapes]

I always use gloves and eye protection whenever I handle champagne.

You must be the life of the party at those fancy restaurants you write about!!

 

[JohnT]

A starting SG of 1.120 has about 39 ounces of sugar per gallon.
For 6 gallons, that is about 470 ounces of sugar
470 ounces of sugar is about 38.75 moles of sugar
38.77 moles of sugar, fermented, produces about 950 liters of CO2 gas at 1 atmosphere and 25 degrees centigrade.

The pressure then depends upon how much you want to compress the 950 liters of gas. Note: a lot of the CO2 will stay in solution and not contribute to the pressure.

You sound like your are truly up on the math. I have read that there is a point where the pressure and also CO2 becomes toxic to the yeast and kills it, so I do not think you will get the full 950 liters of gas.

 

[StevenD55]

I have read that there is a point where the pressure and also CO2 becomes toxic to the yeast and kills it, so I do not think you will get the full 950 liters of gas.

Interesting. I decided to check that out. It sounds like there are some issues with fermentation under pressure and even pH impacts according to one source since CO2 cannot be released.

I did find this from Lallemand/Danstar yeast.

(http://www.danstaryeast.com/articles/conical-fermentation-effect-yeast)

CO2 @ 0.2 atmospheres pressure stimulates yeast growth.
CO2 @ 0.5 atmospheres pressure begins to exert a negative effect on yeast growth.
CO2 @ 3.0 atmospheres pressure stops growth
CO2 @ 3.0 atmospheres pressure does not stop fermentation-alcohol production.