How many times do you reuse your bottles?

[oogaboogachiefwalkingdeer]

Until they get a hole in them.

 

[doug293cz]

All materials fatigue if you apply enough stress.

Be careful of absolutes. Gases and liquids don't fatigue. Gold is so ductile that it doesn't fatigue when being deformed. That's why you can make gold leaf by pounding it out to ridiculously low thicknesses.

The fatigue stress level for most materials is way lower than the level at which it will deform, so there is no way of knowing how much the material has weakened. Depending on the stress level, a material may last a few cycles, or millions before failure.

I think the highlighted statement conflicts with what most people who have learned about fatigue were taught. Do you have any support for that statement, and can you provide references? Would be nice if the references explained on a molecular level what leads to fatigue at very low stress levels. Not saying you're wrong, it's just not the way I learned it.

Brew on

 

[doug293cz]

I had one batch go to 9 volumes (only 1 bottle broke) - I measured the gravity from another bottle to determine the carbonation level.

Can you explain how you used gravity measurements to determine carb levels? It's not immediately clear to me how this would be done, and it sounds like it might be a useful method to know.

Thanks, and brew on

 

[unionrdr]

There are some 8 different formulas out there I've seen. But I use the Cooper's one that agrees with Beersmith2 so far; (OG-FG)/7.46 + .5= ABV%. So if your OG was 1.053 & your FG was 1.012, then, (1053-1012)/7.46 +.5=ABV% or 41/7.46 + .5 =ABV . 5.49597855227882 rounded off to 5.49 + .5 = 6.4% ABV.

 

[doug293cz]

There are some 8 different formulas out there I've seen. But I use the Cooper's one that agrees with Beersmith2 so far; (OG-FG)/7.46 + .5= ABV%. So if your OG was 1.053 & your FG was 1.012, then, (1053-1012)/7.46 +.5=ABV% or 41/7.46 + .5 =ABV . 5.49597855227882 rounded off to 5.49 + .5 = 6.4% ABV.

Ok, but how do you get from ABV to carbonation level?

Brew on

 

[unionrdr]

Ok, but how do you get from ABV to carbonation level?

Brew on

Oh, so you're asking about volumes of Co2? You can do that easilly with a priming calculator. Like these;
http://www.northernbrewer.com/priming-sugar-calculator/
http://www.tastybrew.com/calculators/priming.html
Input the style of beer & your numbers & it'll give you Vco2.

 

[Calder]

I think the highlighted statement conflicts with what most people who have learned about fatigue were taught. Do you have any support for that statement, and can you provide references? Would be nice if the references explained on a molecular level what leads to fatigue at very low stress levels.

No references, but if you look in any material handbook, you will find everything you need to know. Try googling Aerospace Materials Handbook, and research some steels or aluminum materials in it. The data should be there. I work in the Aerospace industry and material fatigue is a critical item. Just winging some numbers off the top of my head, but; cast aluminum yield strength is about 30 KSI. Yield is where it will permanently deform (plastic rather than elastic), but High Cycle Fatigue stress (the level you want to stay below to ensure infinite life) is around 12 KSI. These numbers are for high temperature applications, I don't know what room temperature capabilities are since I deal with hot parts.

...... And (before someone brings it up), there is actually no lower limit for aluminum for fatigue. It may take billions of cycles to fatigue, but aluminum will eventually fail at whatever level of stress you give it, if you cycle it enough times.

Can you explain how you used gravity measurements to determine carb levels? It's not immediately clear to me how this would be done, and it sounds like it might be a useful method to know.

I bottled to 3 volumes. One bottle broke. I immediately put the rest in the fridge and set about consuming them as quickly as I could. I opened one of the beers, and let it go flat, and then took a gravity reading. It has been a while now, so my numbers may not be correct as I'm not looking them up, but I think I bottled at 1.016 (an Oatmeal Stout) and when measured sometime after bottling, it was something like 1.009. I calculated the difference in gravity to be about 6 volumes of CO2. Add that to the 3 I bottled at = 9 volumes.

 

[doug293cz]

No references, but if you look in any material handbook, you will find everything you need to know. Try googling Aerospace Materials Handbook, and research some steels or aluminum materials in it. The data should be there. I work in the Aerospace industry and material fatigue is a critical item. Just winging some numbers off the top of my head, but; cast aluminum yield strength is about 30 KSI. Yield is where it will permanently deform (plastic rather than elastic), but High Cycle Fatigue stress (the level you want to stay below to ensure infinite life) is around 12 KSI. These numbers are for high temperature applications, I don't know what room temperature capabilities are since I deal with hot parts.

...... And (before someone brings it up), there is actually no lower limit for aluminum for fatigue. It may take billions of cycles to fatigue, but aluminum will eventually fail at whatever level of stress you give it, if you cycle it enough times.

Yield stress is an engineering definition, conventionally set at some fixed amount of deviation from the linear portion of a stress/strain curve resulting from a standardized test. Plastic deformation starts as soon as stress is sufficient to cause any change in the microstructure of a solid material, even if the deformation is not detectable at a macroscopic level. These microstructural changes can occur at much lower stresses than the yield stress, as you have noted. It's the microstructural changes that accumulate over time, and multiple cycles, which eventually lead to fatigue and failure. I'm no expert on aluminum, so have no idea at what stress level microstructural changes can occur.

I bottled to 3 volumes. One bottle broke. I immediately put the rest in the fridge and set about consuming them as quickly as I could. I opened one of the beers, and let it go flat, and then took a gravity reading. It has been a while now, so my numbers may not be correct as I'm not looking them up, but I think I bottled at 1.016 (an Oatmeal Stout) and when measured sometime after bottling, it was something like 1.009. I calculated the difference in gravity to be about 6 volumes of CO2. Add that to the 3 I bottled at = 9 volumes.

Ok, I get the general idea. Thanks.

Brew on

 

[VT-NAV]

^^^ this!

I had some bottles of stout blow up on me. It's enough to put the fear of God in you when you start handling the other bottles.

My bottle collection grew immensely when my father-in-law, a prolific beer drinker who runs marathons to stay in shape, started saving his empties for me. For two months in 2013, he was giving me two or more cases of Sierra Nevada bottles a week. Eventually I had more than I could store.

About six months later, I started getting bottle bombs. It wasn't very many (about 5 bombs in total over the course of about 300 beers bottled), but for me, one bottle bomb is too many. Every time I got a bottle bomb, I would carefully uncap and pour out the rest - I will not risk an exploding bottle potentially injuring a family member.

I was at a total loss to explain the first couple bottle bombs. Even though my sanitation is extremely thorough, my first thought was that I had made a mistake somewhere that resulted in infection. My palate isn't very sensitive, so I thought I must be missing subtle off-tastes that an infection would produce. I went crazy cleaning and sanitizing my major pieces of equipment. Long soaks in PBW followed by high-pressure rinsing, followed by another PBW soak and rinse, followed by a bath in Star-San. After cleaning all my glass, I also sanitized it with a strong bleach solution. I replaced everything else that was relatively easy to replace; e.g., auto-siphon, tubing, bottling spigot. On the next batch I brewed, I went nuts making sure nothing was contaminating my wort during cooling and transfer - every opening had aluminum sprayed with Star-San guarding it. I threw away all my banked yeast (even though pretty much all of it was first or second generation) and started fresh. I thought I was good.

Then I got a couple more bottle bombs on my next batch.

Since the problem didn't seem to be infection. I figured I must be bottling before achieving FG. I don't use secondary fermentation, but I tend to let my beers ride a long time in primary. After dozens of batches, I'd never had a beer fail to reach FG by 8 weeks, and I had neglected to do FG readings for the bottle bomb batches.

So, I did another batch carefully repeating my detailed sanitation steps and meticulously measuring everything to include FG. When gravity was stable for two weeks, I bottled. I was also very precise with my priming additions.

And I got another bottle bomb.

I was really pissed and disappointed. I felt like I'd done everything as best as I could, and I still couldn't get it right. I took a good, long break from brewing.

One night, I was at my father in law's house for dinner with the family. He and I were chatting in the kitchen when he poured himself something from Sierra Nevada. After the pour, he tossed the empty bottle into a bin he keeps in the pantry for beer bottles (he empties it in the morning). There were already a number of bottles in there, and it made a hell of a racket when he threw one in. A light went on in my brain. I asked my father in law if the bottles he saved for me were tossed in the bin, and then fished out in the morning. Yup.

When I got home I went through my bottle collection with a very bright light. The Sierra Nevada bottles had small cracks, chips, and other camouflaged problems I had never noticed before. I threw them all out and haven't had a bottle bomb since.

 

[wilserbrewer]

Thanks guys...I guess basic materials science hasn't changed much in the last 30 years

Just as I suspected, the life of a bottle is somewhere between zero and infinite uses...

I did play briefly with heat sanitizing bottles in the oven years ago and lost a few bottles due to cracks / breakage likely due to heating cooling too quickly or unevenly. Probably not a great idea, and also a bit of a hassle IME. Some people love heat sanitizing bottles in the oven / dishwasher.

 

[Kee]

I bottled to 3 volumes. One bottle broke. I immediately put the rest in the fridge and set about consuming them as quickly as I could. I opened one of the beers, and let it go flat, and then took a gravity reading. It has been a while now, so my numbers may not be correct as I'm not looking them up, but I think I bottled at 1.016 (an Oatmeal Stout) and when measured sometime after bottling, it was something like 1.009. I calculated the difference in gravity to be about 6 volumes of CO2. Add that to the 3 I bottled at = 9 volumes.

According to this:
http://braukaiser.com/wiki/index.php/Accurately_Calculating_Sugar_Additions_for_Carbonation

1 gravity point drop will add about .51 volume of CO2 (last line under the title Remaining or Residual Effect).

I have seen other values (higher) for this. Is there a different formula that you are using? I've been taking this as gospel but really don't know if this is accurate or not.

 

[unionrdr]

It's the heating & cooling cycles that can cause stress fatigue cracks, etc. they can be very small & nearly unnoticeable. Kinda like magnafluxing crankshafts & such. In this case, I don't think the pressure the average beer puts on the bottles to be of much concern. It's basically how the bottles are treated that matters most.

 

[Calder]

1 gravity point drop will add about .51 volume of CO2 (last line under the title Remaining or Residual Effect).

I have seen other values (higher) for this. Is there a different formula that you are using? I've been taking this as gospel but really don't know if this is accurate or not.

I forget how I calculated it in the past, or even if I am using the right numbers now. But just as a check I just pulled up a recipe in Beersmith (just the first sample recipe I found). Adding 12 ozs of corn sugar gave a gravity rise of .007. Checking the carbonation calculator, it says 12 ozs of corn sugar will give 5.7 volumes of CO2 - less the entrained CO2 (which looks like it is 1.2 volumes), would mean .007 change in gravity = 4.5 volumes.

Maybe my beer was 7.5 volumes (3+4.5). I can't remember the actual numbers, but it seemed to work out to 9 volumes at the time.

 

[ExcuseRobin]

I don't bottle as much anymore since I started kegging, but my original 22oz bombers from 5 years ago are still working fine and I've never had an issue.
In Europe they reuse bottles almost exclusively. You get a beer and the bottle is all scuffed up because they reuse instead of recycle, and based on how gnarly some of the bottles look we're talking hundreds of times most likely.

That's not true at all. In Europe we recycle, but bottles are remade from scratch.

 

[doug293cz]

Thanks guys...I guess basic materials science hasn't changed much in the last 30 years

I hope not, since I graduated ~40 yrs ago

Brew on

 

[unionrdr]

Ha, yeah. When I graduated high school, material science was flint swords & bear skins. But proper care will make them reusable for a long time to come. They better last, the old style Paulaner bottles with the bearded monks on the shoulder aren't made anymore! Seems like the German bottles seal better with their unique lip design?

 

[doug293cz]

Is there a reliable way to determine when they will break? No.

Sorry about the self quote, but on further reflection, there is a way to tell if a bottle is strong enough to use safely. The method is a hydrostatic test, similar to what we have to have done to our CO2 cylinders periodically.

A hydro test is a type of proof test, which simply tests if the bottle is strong enough to withstand expected maximum use pressure + a safety margin. It the bottle doesn't break during the test, then all of the preexisting defects are small enough that no stress concentration due to them, at working pressure, will be enough to cause failure. The test is short enough that no significant stress corrosion (crack growth) can occur during the test, and the test pressure is low enough that it will not cause microstructure deformation (fatigue) on it's own. So, if the bottle survives the hydro test it is safe to use, and if not, then you can't use it anyway.

To select the pressure for a hydro test: pick a maximum possible carb level (let's say 10 volumes to keep Calder out of trouble ), and a maximum possible storage temperature (let's say 110°F). So, we have to figure out the pressure that corresponds to 10 volumes of CO2 @ 110°F, and that is the proof pressure. Of course, if all or most of bottles break at this pressure, then we would have to settle on a lower pressure with a smaller safety factor (no more priming to 9 volumes.)

Pressure should be applied using a liquid (water is probably best) rather than air, as the driving force behind shrapnel acceleration drops off much faster with an incompressible fluid than with a gas. Still, a shrapnel shielding enclosure for the apparatus is a must. You'd want to suspend the bottle from the neck, but with jaws specifically designed to prevent possible damage to the neck (unlike wing capper jaws. ) Then we just need a stopper with plumbing connecting it to a high pressure, flow restricted, water source.

Any demand for such a tester? Any DIY'er want to take it on?

Brew on

 

[unionrdr]

10 Vco2 is a whole lot higher than the 3 1/2 Vco2 they say the average beer bottle can withstand. I didn't go higher than 2.8 Vco2 with my hefe & still got plenty of carbonation. Drove the head like a winter tornado.

 

[doug293cz]

10 Vco2 is a whole lot higher than the 3 1/2 Vco2 they say the average beer bottle can withstand. I didn't go higher than 2.8 Vco2 with my hefe & still got plenty of carbonation. Drove the head like a winter tornado.

10 volumes was a little tongue in cheek, but the example works anyway for illustration. 5 volumes might be more reasonable for proof testing with some safety margin for normal cases. I've seen the 3.5 volumes number mentioned seveal times, but never seen an authoritative reference for the number. And a volume number by itself is not sufficient. We also need to know the max assumed temperature, since the pressure increases significantly with temperature for a given volume.

Brew on

 

[unionrdr]

Yeah, some empirical data would be great. Never actually saw that yet...

 

[user 30639]

Some pretty interesting information in this thread. I usually use mine until I see gunk in them, and then they go in the recycling bin.

 

[ol-hazza]

Every now and then I take pity on the world due to the fact they don't live in New Zealand..

Over here we have a phenomenon called swappa crates, which are a wooden crate of 12 745ml bottles which when emptied can the be returned and swapped for a full one at discount price.

The bottles are thick glass and take a beating, and have the added advantage that every single house in the country has at least one full crate!

Being made specifically to be reused, they are very unlikely to cause you any trouble. A mate of mine carbed some cider using dry ice in these bottles and it went horribly wrong, and opening a bottle resulted in a cider shower, but still none bombed.

Also if they get too dirty or cracked, you just put them aside and when you have a full crate go and swap it out for a full one. Most bottle stores will also sell them too you for about $5-6.

The pine crate can also be used as fire wood at a pinch, as only the bottles are counted and not the actual crate.

The one problem I had with them was when i was using boiling water to sterilise bottles, and the bottom popped off one of them, i'm thinking because of some cold water on the bench at the time.

So yeh i re-use bottles a lot.

 

[beerenstein]

The most recently bottled batch of beer I bottled was done with 1 full cup of agave nectar in about 4.5gallons of porter(I wanted to see what highly carbonated porter tastes like [it had an interesting mouthfeel and taste ]) It has more fermentables than a cup of table sugar. I'm a novice, first time bottling with glass bottles. No bottle bombs.

 

[Calder]

The most recently bottled batch of beer I bottled was done with 1 full cup of agave nectar in about 4.5gallons of porter(I wanted to see what highly carbonated porter tastes like [it had an interesting mouthfeel and taste ]) It has more fermentables than a cup of table sugar. I'm a novice, first time bottling with glass bottles. No bottle bombs.

Agave nectar is a syrup. The fermentable Part of Agave nectar is sugar. 1 cup of Agave nectar has less fermentables than 1 cup of sugar because it also has some water content. It probably has 25% less fermentables than sugar.

 

[beerenstein]

Agave nectar is a syrup. The fermentable Part of Agave nectar is sugar. 1 cup of Agave nectar has less fermentables than 1 cup of sugar because it also has some water content. It probably has 25% less fermentables than sugar.

Hah! Noob Misunderstanding by myself! Notice that this document says 40% sweeter. I'd read something wrong at some point. But that porter IS highly carbonated and definitely has a great taste and bite to I.