Hurricane brewing question

[The_General]

I was enjoying the beautiful weather yesterday and I got call from a fellow brewer. He brewed an imperial stout yesterday around noon and pitched a starter. I don't have any more details than that but when he called me around six, his air lock was bubbling like nothing either of us had seen before.

Since then, he had talked with his dad and they came up with a theory that the low air pressure associated with the hurricane caused increased gas coming off the wort. I know things like this are possible under much lower pressure. It's used in labs all the time to quickly evaporate solvents. This seems plausible to me but I don't know if the pressure difference is enough to notice a difference. Have you guys ever heard of something like this? Do you think it's possible?

 

[bovineblitz]

Does he often make imperials? My bigger beers tend to go crazy. Also, did he use a new yeast this time?

 

[The_General]

I don't have any more details than what I posted. I guess what I'm not asking whether it happened or not in this case. We don't have enough information to definitively say. I'm asking whether you think it's possible to see an effect.

 

[The_General]

There is another storm forming now that could possibly go the same way Irene did. Maybe I could devise an experiment.

 

[ChillWill]

If he pitched a big enough starter, then its probably just fermenting nicely. I've had "airlock activity" within 3 hours from dry yeast before... maybe over pitched a bit or it could have just been pressure change as the wort warmed to room temp, but there weren't any hurricanes that day.

 

[dcp27]

I'm pretty sure its just coincidence. The outside pressure from the hurricane is indirect since it has to pass through the water in airlock first. Besides, the air pressure drop during a hurricane is pretty insignificant (~5%) and nowhere in the realm that is used in a rotovap.

 

[solbes]

I dunno, it's possible. I have witnessed a similar effect in person.

Ever travel in an airplane with a "gassy" co-worker? I have. I swear there was a noticeable increase in "activity"

 

[bovineblitz]

I don't have any more details than what I posted. I guess what I'm not asking whether it happened or not in this case. We don't have enough information to definitively say. I'm asking whether you think it's possible to see an effect.

I doubt that there would be much of an effect, much less a visible one.

 

[unionrdr]

That's the kind of difference I get between using 2tsp dextrose in re-hydrating water vs a small starter of the same size. The sugar hydrate will bubble quick & steady by morning,some 10-12 hours later (that I notice). The starter will need a blow off by then,having started bubbling in about 9 hours. Then it sounds like beer soaked bbq farts in a bathtub.
Now,just imagine lighting one at 60,000 feet! Talk about a blow out!:cross:

 

[prrriiide]

Interesting hypothesis.

The central pressure for Irene was 950 mB (28.05 inHg) at landfall. For comparison, that's the same as Wilma was in 2005 when she blew away a good part of Key West. Camille was 909 (26.84), Katrina was 920 (27.17), and Andrew was 922 (27.23). So the pressure with Irene wasn't that low as far as hurricanes go.

1 standard atmosphere is defined as 1013.25 mB, or 29.92 inHg. So if you look at the difference in intensity between Irene at 950mB and Camille at 909 mB, you get a difference of 41 mB. So with a difference of 63 Mb between Irene's central pressure and the standard atmosphere, you might be on to something.

You can also look at the difference between Irene's central pressure and the lowest pressure ever recorded, 850 mB, which was in the EF4 tornado that hit Manchester, SD. - 100 mB difference. That's a pretty steep pressure gradient.

 

[unionrdr]

And then throw in how far you are above sea level. Bit more of a difference?

 

[DrJerryrigger]

Altitude wouldn't make a difference. It's the sudden change in pressure.

If you have a beer fermenting at a high rate under normal pressure there is a large amount of CO2 suspended in it. If you reduce the pressure; lots of this will come out. This action will also stir things up and may help the yeast eat a little faster.

This is why counting bubbles on your air lock isn't a true indicator of fermentation, unless you also know the barometric pressure (and if it's changed) and how much CO2 is in your beer.

 

[The_General]

Actually, altitude could make a difference. If you suddenly took a fermenter to a higher altitude, you should lose more gas out of solution. Your airlock would bubble more.

This is getting into all kinds of nerdy questions but here we go. Would you see lower attenuation if you fermented in a sealed system? In other words, could you reach a high enough pressure to keep enough CO2 in solution to inhibit the enzymes to make alcohol?

Sorry but I'm a grown up science nerd who gets a kick out of thinking about these things. Maybe I should be studying fermentation science instead of what I am studying

 

[tarponteaser]

I brewed a batch of ale with cranberry sauce as an adjunct for Thanksgiving many years ago. We had a fast moving hurricane come through central FL while it was fermenting and the airlock became a gusher of red froth. Reduced partial pressure on the airlock will increase outgassing.

Regards

 

[DrJerryrigger]

Actually, altitude could make a difference. If you suddenly took a fermenter to a higher altitude, you should lose more gas out of solution. Your airlock would bubble more.

This is getting into all kinds of nerdy questions but here we go. Would you see lower attenuation if you fermented in a sealed system? In other words, could you reach a high enough pressure to keep enough CO2 in solution to inhibit the enzymes to make alcohol?

Sorry but I'm a grown up science nerd who gets a kick out of thinking about these things. Maybe I should be studying fermentation science instead of what I am studying

That's if you could move it to a higher elevation with out shaking it, as we all know shaking can remove CO2.

As to your question. I don't know, but I'd guess no. Yeast can make some very high pressures and seem to keep going. I've blown up two 1 gal carboys (Carlo jug) and I would think that such a container could hold quite a lot of pressure. Though, with most things there is a maximum limit, with this one, I don't know what the limiting factor would be (other than the vessel that is).

And what are you studying?

 

[DrJerryrigger]

I just noticed my air locks have stopped, so I looked up the barometric pressure in my area and it has been rising over the last few hours. Then I thought of this thread, so I thought I'm mention it.