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evenstill
05-10-2007, 06:58 PM
Can anybody tell me how much pressure (psi/bars/atm) can safely be handled by a standard beer bottle, flip-top beer bottle, and regular wine bottle?

Thanks,
evenstill

akueck
05-10-2007, 08:38 PM
Most beers have about 1 atm of pressure on/in them, so standard beer bottles can handle that. Flip-top shouldn't change that unless the glass is thicker.

Standard wine bottles aren't meant to handle any pressure, so I would personally not put any pressurized liquids in them (closure would also be more difficult). Sparkling wine bottles can be pressurized. A Martinelli's bottle (not wine, but the bottle is the same size) can handle beer pressure. Big hefty Champagne bottles can take up to 6 atm. These bottles are significantly heavier than standard bottles and their punts (the bump on the bottom) are pretty big.

Rule of thumb: you can refill a container with its original contents at their orignial pressures (beer in a beer bottle, etc) safely. Be sure to inspect for cracks & chips though.

evenstill
06-06-2007, 06:55 PM
Ok, so I just got some new 12 & 22 oz beer bottles from a local homebrew shop and would like to put some sparkling cyser in them. My target CO2 volume is 2 (8g sugar per liter?). I’ve read that most beer bottles purchased in the U.S. can safely handle 2-3 atmospheres of pressure so I shouldn’t have any problems right?

akueck
06-06-2007, 07:43 PM
A "typical" beer pressure is 2.5 volumes of CO2. You'll be fine at 2. I'm planning on bottling a weisse at 3.5 volumes, and it seems that the bottles should be able to handle that too. It's hard to find numbers, but one place I saw said beer bottles "may" handle up to 50 PSI (about 3 atm), another place said 100 PSI (though that seems like a stretch). 2 volumes is less than 15 PSI (about 1 atm), so you're well within the limits.

evenstill
06-06-2007, 11:50 PM
Am I understanding you correctly that 2 volumes is NOT 2 atm? I'm getting mixed language from folks and am getting rather confused. I was under the impression that 1 atm was the same as 1 bar, 1 volume, & about 15 psi and that 4g corn sugar per liter of mead would yield 1 atm/bar/volume/15psi and an additional 0.216% ABV. I'd really like my cyser to have about as much sparkle as an average beer (2.5 atm) but figured that I'd shoot just a little under to leave some room for mistakes. Am I off on my language, units of measurement (atm etc.), and/or calculations?

akueck
06-07-2007, 02:14 AM
Yeah, it took me awhile to get used to the "volumes" of CO2 thing. Basically, if you take all the CO2 out of 12 fl oz of beer and get 12 fl oz of CO2 (at standard temp and pressure), that's one volume of CO2 in your beer. 1 volume is basically flat (you'll have about that much left over at the end of fermentation before degassing). Applying 15 psi/1 atm of pressure on a liquid will give you some amount of carbonation, which depends on the temperature. Higher temperature, less carbonation. Look up a carbonation chart if you like, it will tell you the psi needed to get a certain number of volumes of CO2 into a liquid.

If I'm doing my conversions right, your 8 g/l of sugar is on the high side of normal for carbonation level (5.2 oz per 5 gallons, standard rates are usually 4-5 oz).

Someone (sorry I don't remember who) posted a link to <a href="http://hbd.org/cgi-bin/recipator/brew/widgets/bp.html">this calculator</a> which will give you how much sugar to add to get to your desired carbonation level. It's a ballpark only (depends on how long it's been degassing, etc), but it's a nice start.

evenstill
06-07-2007, 09:31 AM
Thanks for being so patient with me . . . your answers are really helping to clear some things up.

So 2 "volumes" is NOT 2 atm, right? What is the conversion (1"volume" = ?atm & ?psi)? Once I know that I should be able to use that link you sent me . . . looks like it'll make things a lot easier.

Let me run my calculations by ya.
I have 3.785411784 liters (1 gallon) of cyser and want to achieve 2 atm carbonation (average beer?) by priming the whole batch with table sugar then bottle aging. 3.8g cane/table sugar per liter of cyser should yield 1 atm carbonation.
If I degass the cyser then I should be able to use the folowing equation:
3.8(grams sugar)* 2(atm carbonation)* 3.785411784(volume liters)=28.769128g (1oz) sugar to add to my cyser.
Sound about right?
I have some formulas that will figure in the residual CO2 in my cyser after brewing (I assume this is for those who don't degass right?) but I believe they are in "volumes" and not atm so knowing the conversion will really help me out a LOT.

zionpsyfer
06-07-2007, 07:29 PM
Correct, "Atmospheres" is a measurement of pressure equal to the measured air pressure at sea level.

PSI, likewise is a measurement of pressure.

1 ATM of pressure is equal to 14.696 PSI.


In physics, Volumes is not a measurement of pressure, but of volume (or amount).


Someone jump in if I end up muddling this next part....


As air is compressible, it's pressure is a combination of the amount of gas and the size of the space it is compressed to (temperature effects this as well).

An empty beer bottle, just sitting open is filled with 1 volume and thus its pressure at sea level is 14.696 PSI. Fill it with 2 volumes and its pressure is now 29.392 PSI.

That link that Akueck posted above shows volumes between 1.3 and 3.5. Giving pressures from 22.044 PSI to 51.436 PSI.

The thin screw top beer bottles in the US (edit:) at the beer company that I work for /edit are tested to 100 PSI (not every one is tested though, just perhaps one in a hundred. So a safer target would be 50 PSI max pressure). I'm not sure how thick the bottles you purchased are, but it's good to know your upper limits. ;)





Hopefully that helps and I didn't get anything wrong. One thing to remember is that I completely disregarded was the volume of liquid as it's non compressible and it's assumed that the gas is dissolved within it. Someone confirm this is correct?

evenstill
06-07-2007, 10:10 PM
Forgive me for being such a perfectionist . . . I guess I'm just the sort of guy that needs the cozy comfort of calculations and formulas to sleep at night. Ya know, the kind that spends a ridiculous amount of time trying to hammer out a "perfect" recipe that will achieve exactly what is desired? Questions . . . questions . . . question . . .

So "Volumes" measure volume and Atmospheres measure pressure but what exactly is the correlation between the two? ???

Since 2 "volumes" = 29.392psi and 2 atmospheres = 29.392psi then 2 "volumes" = 2 atmospheres? ???

Are "volumes" and atmospheres interchangeable units of measurement when it comes to formula intended for bottle priming? ???

If, as you suggest, my bottles can probably handle 50 psi (about 3.5 atmospheres of pressure) and I'm shooting for 29.392psi (2 atmospheres of pressure) I can safely calculate the amount of priming sugar needed by using a formula intended to achieve "2 volumes"? ???

And how does the volume of liquid affect all this? ???

akueck
06-08-2007, 03:09 PM
3.8(grams sugar)* 2(atm carbonation)* 3.785411784(volume liters)=28.769128g (1oz) sugar to add to my cyser.
Sound about right?


Like I said, 4-5 oz per 5 gallons is typical for beer priming. So 1 oz/gal is good; considering you'll degas it, it should wind up about average beer carbonation level.

The problem equating "volume" and "pressure" is the fact that it all depends on temperature. So a <a href="http://www.ebrew.com/primarynews/ct_carbonation_chart.htm">carbonation chart</a> will list the temperature and the pressure (supplied by you) and give you the resultant "volumes of CO2".

Another problem is "absolute pressure" vs "gauge pressure". The carbonation charts all work with gauge pressure since they usually assume you're hooking up a draft system and are reading pressure via a gauge. To get from gauge to absolute pressure, add 1 atm/14.7 psi (at sea level). So your carbonation chart will give you 15 psi for 2 volumes at 58ºF. In absolute terms, this is really 2 atm at standard conditions (one at the gauge and one for ambient air).

So, as best as I can see it, when you're working with standard conditions, "1 volume" of CO2 exists in a container at "1 atm". Change the temperature and it all goes out the window.

Stay within the window of 0.8-1 oz of corn sugar per gallon, and you won't blow up the bottle, even without degassing. The best teacher for this is experience, so you'll just have to make lots of sparkling cyser "in the name of science". :laughing7:

akueck
06-08-2007, 08:11 PM
An empty beer bottle, just sitting open is filled with 1 volume and thus its pressure at sea level is 14.696 PSI. Fill it with 2 volumes and its pressure is now 29.392 PSI.


This is correct, but misses the point a little. "Volumes of CO2" refers to how much gas is dissolved in the liquid, not how much volume there is or what pressure there is. The pressure and temperature affect how much gas dissolves in the liquid (high pressure favors dissolution, high temperature favors degassing). Beer with 2 volumes of CO2 in it has enough dissolved gas to fill twice the volume of the beer, were the gas to be removed and placed at standard conditions. The same bottle of beer, placed at a lower temperature, will have more volumes of CO2 in it (some CO2 from the headspace will dissolve into the liquid). The pressure in the bottle will decrease, yet the volume (not "volumes of CO2", just regular volume) is the same. Hence the precaution to never open sparkling wine at room temperature (just chilling it will make it less dangerous to open).

Use the calculator I linked to eariler. It will estimate the amount of gas remaining at the end of fermentation (less as the temperature increases). The longer your cyser sits, the more gas will leak out, but if you prime within a month or so of the end of fermentation I'd say the calculator should be about right. Enter your desired carbonation level (say 2 volumes) and the volume of cyser (1 gallon) and out pops how much sugar you need (0.6 oz). If you degas, you'll need an additional 0.45ish oz of sugar to make up for what was there (leading to your 1 oz calculation earlier).

I used the calculator to figure out how to prime my almost-flat (1.5 volumes) English Mild ale, and it worked great. Yay calculator! ;D

So, in summary, there is no nice formula for "volumes CO2" = "atm/psi". Temperature and gas dissolving in liquid just make the situation screwy.

evenstill
06-16-2007, 06:05 PM
Thanks everyone for the great replies. This is just the kind of info I was looking for.

I think it's to late for one of my batches of Cyser though. I checked the gravity today and it's the same as the last time i took it which was 2 weeks ago (1.0236). This means that there hasn't been any fermentation in the last 2 weeks right? This gravity gives me about 6.792% sugar by weight right? I assume that if there was any life left in my yeast (Wyeast 4632 dry mead) it would have been fermenting this residual sugar for the past 2 weeks so if I added any sugar at this point to bottle prime it would just serve to make it sweeter, not sparkling right? It's really clear with little to no yeast at the bottom and since I haven't seen a change in gravity for 2 weeks is it ok to go ahead and bottle it then?

Thanks,
evenstill

Oskaar
06-17-2007, 04:19 PM
Thanks everyone for the great replies. This is just the kind of info I was looking for.

I think it's to late for one of my batches of Cyser though. I checked the gravity today and it's the same as the last time i took it which was 2 weeks ago (1.0236). This means that there hasn't been any fermentation in the last 2 weeks right? . . . I haven't seen a change in gravity for 2 weeks is it ok to go ahead and bottle it then?

Thanks,
evenstill


No, that's not a safe assumption to make.

Zero change in gravity for a period of two weeks is far too short a period to assume that the mead has stabilized. I've had meads that have sat for 3-5 months with no change, then BLAMMO, off they go again. This is even after 2 rackings. The problem with not filtering or sulfiting and sorbating is that you're at the mercy of time and guesswork. You cannot see the yeast with the naked eye, and while mead can appear clear, it can still have a significant enough population of yeast in suspension to begin fermenting again. You need to monitor the mead for several months (more than three in my opinion) in order to make that leap. Even then you're rolling the dice. If you want to stack the odds in your favor you should cold crash the carboy at about 39 degrees for two weeks and immediately rack after that time. Take a gravity reading after the mead has come up to room temperature and monitor again for eight weeks. At that point if you see no changes in gravity I would still cold crash again for a week and monitor for another four afterwards. Then I'd feel safe bottling. That's no guarantee by the way, but it seems to work for me on a pretty regular basis.

Hope that helps,

Oskaar