Can you tell what the bottle pressure limit is by what its weight per oz is. Here are some different bottles and what they weigh per oz:
Sierra Nevada, 16.7g/oz
RR Pliny, 21.7g/oz
Green Flash, 25.8g/oz
Logsdon, 27.5g/oz
RR Temptation, 31.5g/oz
Orval, 31.6g/oz
The Green Flash bottles are 9.1g/oz heavier than Sierra Nevada. The Green Flash are only 1.7g/oz lighter than the Logsdon bottles which are usually very highly carbonated. I want to bottle some Saison at around 3.5 volumes of CO2. Do you think the Green Flash bottles will be fine?
I like the chart. I’ve also noticed the substantial heft of Green Flash bottles and kept some for use because of that. You’re good with higher pressure in those GF’ers.
I tend to avoid embossed (Green Flash, New Belgium) and silk-screened (Stone) bottles when my mind is too much on acquiring a bottle that I can re-brand as mine. But I couldn’t bring myself to drop those GF heavies into the recycle bin.
I have a friend in the glass bottle business. Here’s what I asked him and his reply.
Hi Manny,
I’ve been following a thread on the AHA forum about the weight of commercial glass beer bottles and its relationship to the strength or volume of CO2 pressure they can hold. Is there a relationship or not? If one 12 ounce bottle (Green Flash) weighs significantly more than another is there a corresponding pressure safety range?
I’m thinking not so much, but I figured I could ask an expert…
Jeff
There is a difference in the process of how the bottles are made. Most bottles here in the USA are lightweight a process called press and blow. This makes a thin glass bottle used for 1 way production. The other process is blow and blow that makes a thicker glass bottle and much heavier. These are typically used for multiple use bottles like in Europe where they will re fill the same bottle up to 20 times. Both types are pressure tested to the specs of the brewery. Most Bottle conditioned beers are packaged in blow and blow containers for durability. These are preferred by home brewers.
They only sample test bottles from a given mold to find it’s burst pressure. We sell a machine to do this test. It is a distructive test.
Most exploding bottles are because of defects within the bottle. Small bubbles and stones from the furnace get embeded in the glass. Scratches can also cause a problem.
there might be a reasonable correlation, but all things considered the amount of pressure a cylinder will hold is a variable of radius and wall thickness, for a given material. but just based on weight per volume is not adequate due to being able to match this ratio for different configurations of height, radius, for a given volume and wall thickness thrown in for the weight as well.
I’ve got some various punted/flat bottom 750ml champagne-type beer bottles. One style weighs about 550g, the other about 650g. I’ve filled both with ~5 vol of CO2, and have yet to have a failure (knock on glass. . .). I purchased some crownable Belgian-style beer bottles, and those weigh about 550g and are rated from the manufacturer for 7 vol.
I guess I should mention, last year I had a few crown failures at those pressures, but not broken glass. Make sure the crown goes on straight and true!
Who hasn’t encountered a bottle of beer that had become over carbonated? What do you do when you realize your batch of bottled beers are over-carbed (e.g., bottled too soon before reaching FG)?
A practical pearl regarding dealing with over-carbed bottles exploding and how to safely diffuse the situation. If you don’t know the amount of overcarbonation–assume the worst, e.g., champagne-like levels in a bottle not designed for the purpose.
Safety first: Protective eye wear (and face shield), clothing, shoes, and gloves would be advised while handling the bottles. Wrapping the bottle with a thick towel adds another layer of protection during handling and processing. Careful handling and placement of the bottle onto surfaces is also wise.
1.) Chill the bottles down to refrigerator temps. Reasons to do this are: a.) to drive the excess CO2 into solution and b.) slow down/or stop fermentation (and further CO2 production).
2.) Once chilled, take one bottle at a time to a utility sink, set it down inside the sink, spray starsan around crown and neck of bottle, and carefully pry off the crown w/o bending the crown too much. At a minimum, eye glasses and gloves are suggested for safety. A thick towel loosely wrapped around the glass would also help absorb a bottle explosion if it should occur during handling or decapping.
3.) Excess gas will escape, some beer will foam and escape the bottle, as well. Expect to lose an ounce (or even more) if the beer is chilled; however, a warm over-carbonated beer may rapidly disgorge the entire contents of the bottle when opened. A chilled beer will retain some carbonation after recapping and keep the remaining beer reasonably carbonated. If excessively over-carbonated, you may still lose the entire contents of the bottle regardless of beer temp.
4.) Push down on the crown and recap with bottle capper. If the crown falls off, squirt star san onto both sides of the crown and recap.
5.) Rinse off beer foam.
6.) Keep chilled, thereafter.
It’s not perfect, but it allows one to safely defuse the bottle bombs, avoid potential injury to yourself and others, prevent further messes, all while saving most of the beer.
All good advice, but I also would use new caps and get the beer almost to freezing temps, then let it sit uncapped for 15 minutes to off-gas before recapping.
Freshly sanitized and New caps are fine if you’ve got them handy.
Just thought I’d make the point that a gently pried-off bottle cap can be reused if one has a wing capper
