Results of my first in-bottle pasteurization experiment!

BANG!!!!!

I will be cooking up another batch of ginger ale, and this time I really want to be able to ship some bottles off to my mom, who is a ginger freak. I've been wanting to experiment with pasteurizing already carbed bottles at home, but have found no info about it.

You see what the result was, but let me explain the experiment:

I knew the main concern would be the increase in CO2 pressure at elevated temperatures, so I filled a New Belgium bottle with club soda (very fizzy, as you know) and capped it off. I put the bottle in my pressure canner with 1 gallon of water, and started increasing the temp, rather gently, to a simmer. Pasteurization temp should be able to be kept below 180F I think (can't find good tables that aren't for milk), but I was going for a worst case experiment.

I removed the emergency relief valve (rubber plug) from the canner lid so that it was not generating pressure and high temps.

Anyway, about 5 minutes into the simmer, BANG!!! I now know that I'll be looking at low temp pasteurization!

Question: Anyone have a good idea of how the big guys do it? I know it involves hot water spraying of the bottles, but I don't have any temperature information.

Seen any pasteurization time and temp tables used for beer or soda?

PintOfBitter said:

[...]so I filled a New Belgium bottle with club soda (very fizzy, as you know) and capped it off. I put the bottle in my pressure canner with 1 gallon of water, and started increasing the temp, rather gently, to a simmer. Pasteurization temp should be able to be kept below 180F I think (can't find good tables that aren't for milk), but I was going for a worst case experiment.

I removed the emergency relief valve (rubber plug) from the canner lid so that it was not generating pressure and high temps.[...]

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Awesome!! :rockin:
Especially that part about removing the emergency relief valve...err...but no, seriously, this sounds dangerous. I'm no authority, but my guess is that in the commercial world pasteurization has nothing to do with glass bottles. Maybe try pasteurizing before fermentation and bottling? What do I know, I like to freeze my beer bottles to clear up the beer...

I looked through "Brewing, Science, and Practice" where I remembered reading about some pasteurization info.

Here's some quick info:
at 53C minimum time to kill population 56 min
at 60C minimum time to kill population 5.6 min
at 67c minimum time to kill population .56 min

The tunnel pasteurizers have a few zones. They first warm up the bottles, then kick it up to pastuerization temp, then cool them down

It also talks a bit about percentage of co2 in the bottle and percentage of head space, but it doesn't give an exact formula.

scopey said:

Awesome!! :rockin:
Especially that part about removing the emergency relief valve...err...but no, seriously, this sounds dangerous. I'm no authority, but my guess is that in the commercial world pasteurization has nothing to do with glass bottles. Maybe try pasteurizing before fermentation and bottling? What do I know, I like to freeze my beer bottles to clear up the beer...

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I took it as the emergency relief valve was removed so it would constantly vent and not build up pressure. Which is the opposite of dangerous

Bokonon said:

I took it as the emergency relief valve was removed so it would constantly vent and not build up pressure. Which is the opposite of dangerous

Click to expand...

Oh yeah, duh on me

Bokonon said:

I looked through "Brewing, Science, and Practice" where I remembered reading about some pasteurization info.

Here's some quick info:
at 53C minimum time to kill population 56 min
at 60C minimum time to kill population 5.6 min
at 67c minimum time to kill population .56 min

The tunnel pasteurizers have a few zones. They first warm up the bottles, then kick it up to pastuerization temp, then cool them down

It also talks a bit about percentage of co2 in the bottle and percentage of head space, but it doesn't give an exact formula.

Click to expand...

Thanks, this is very helpful. I may need to pick up that book sometime.

Yes, I removed the relief valve for safety purposes. The only reason I used the pressure canner was because it is bomb-proof, and would contain the glass. Good thing. One shard of glass blew out the hole where the relief valve used to be, along with a little shot of boiling water. Overall, a lot safer than it could have been, though.

I'll give it another shot with the temps you describe. Thanks again!

I've never used this type of quipment before so maybe I'm off base here, but it's the temp that kills the badies, so why not keep the canner vessel pressurized. Would that provide a sort of quasi equilibrium (the pressure in the vessel reoghly equivalent to the pressure in the bottle) and prevent the bottle from rupturing?
Obvouisly you'd have to cool it back to room temp before releasing the pressure or else "boom" again.

I understand your line of reasoning, but I think that the increase in pressure in the bottles due to CO2 expansion would far outweigh the increase in pressure in the canner due to heating. Not sure, but that was my assumption. I didn't have any good info for the solubility of CO2 at different temps.

PintOfBitter said:

Yes, I removed the relief valve for safety purposes. The only reason I used the pressure canner was because it is bomb-proof, and would contain the glass. Good thing. One shard of glass blew out the hole where the relief valve used to be, along with a little shot of boiling water. Overall, a lot safer than it could have been, though.

I'll give it another shot with the temps you describe. Thanks again!

Click to expand...

I think the pressure canner is a great tool for this since it is really strong. The only thing that it makes difficult is the lack of way to monitor temperature.

You might be better off without using the lid, putting a lot of water in there so the temp changes are slow, stick a temp probe in the water. You would have to come up with some way to cover the vessel but still let out pressure/steam.

Then you could ramp it up really slowly to see how much pressure it can take.

Most glass bottles aren't really designed for high pressure, but clearly they still get pasteurized by the big guys so somehow they do it.

i've got another experiment in the works today, and will be controlling the temperature of the bottles. stay tuned for results. i can't see how this will fail using Bokonon's numbers, unless my CO2 volume or headspace is way off. again using carbed H2O for simplicity.

If all else fails you could get a keg and Co2 tank just for soda. Carbonate it at room temp, cool it down in a tub of ice to bottle, that way you don't involve yeast at all.

Success! I was able to bring the bottle of highly carbed H2O to 158° without 'sploding. I ran a temp probe through the hole in the lid into a chilled, uncapped bottle of water. I monitored this temp, knowing it would stay close to the temp of the capped bottle. When the temp hit 153° I removed it from the heat, and began running cool water into the canner through the same hole. I removed the lid gasket this time, so when it filled, it just ran out under the lid and into the sink. The bottle temp ended up coasting up to 158 (due to the high temp of the water bath) before it began to cool.

Now that I know that even a highly carbed bottle can be safely brought to pasteurization temps ("safely" assuming some precautions are followed), I'll next try it on some ginger ale!

The next step will be to use a temp controller to switch a hotplate on and off to maintain a water bath at an appropriate temperature. Using this method, it would be much safer to run a big batch of bottles, since it wouldn't be necessary to keep such a close eye on the bottle temp.

Looking forward to the ability to create all natural sodas in bottles!

conpewter said:

If all else fails you could get a keg and Co2 tank just for soda. Carbonate it at room temp, cool it down in a tub of ice to bottle, that way you don't involve yeast at all.

Click to expand...

I'm actually not planning to use yeast at all, I just want to prevent wild yeast/bac from creating bottle bombs in the mail... I'll carb the stuff with a carbonater cap in a 2 liter, or maybe cook up a whole 5 gallons and just dedicate a keg to it for a while.

Watching, watching, watching!

Very cool. Can't wait to see how it turns out.

I pasteurized a sixer of ginger ale and shipped it cross country. It's been at room temp for a week now with no sign of any kind of infection, and nothing exploded in the mail.

During the pasteurization, my temp probe's alarm quit working, so I overshot my temp - got to 180° and one bottle burst. This time I wrapped them all in a towel inside the canner to contain the glass shrapnel, and all was well. I suppose the remaining bottles were "ultra pasteurized" heheh.

I'll definitely continue to do this in the future. I'd recommend a temp controller.

Very cool. Glad it worked out.

How much head space did you end up leaving in the bottles?

It could be an interesting experiment to bottle conditions some beers and pasteurize half of them. Then at different intervals do some side by side tastings to see how the non-pastuerized beers change compared to the pasteurized ones

Just a thought. I read about this being done in Brazil. They stressed in putting some type of "riser" in the heating pot so the BOTTLES DO NOT TOUCH THE BOTTOM OF THE POT. This may be some of your problem. The bottoms of the bottles are getting much hotter than you intend due to the direct contact with the heat source (bottom of the pan). Try using a steamer tray (or something else that allows the water to pass through) under the bottles to keep the heat on the bottles more uniform.

Hope this helps.
Dougieb

I've read about this being done in Brazil. One thing they stressed is to put some sort of "riser" under the bottles. It is very important to keep the bottom of the bottles from touching the pot. This would put the bottles in direct contact with the heat source.

Try using a steamer tray (or something that lets the water pass through but keeps the bottles off the bottom).

Maybe this will keep the temps more uniform on the bottles.

Hope it helps.
Good luck.

Dougieb

Dougieb said:

I've read about this being done in Brazil. One thing they stressed is to put some sort of "riser" under the bottles. It is very important to keep the bottom of the bottles from touching the pot. This would put the bottles in direct contact with the heat source.

Try using a steamer tray (or something that lets the water pass through but keeps the bottles off the bottom).

Maybe this will keep the temps more uniform on the bottles.

Click to expand...

Since he is using his pressure cooker I suspect the riser is installed in it just like you would do for canning, but it is a good point

Bokonon said:

Since he is using his pressure cooker I suspect the riser is installed in it just like you would do for canning, but it is a good point

Click to expand...

Yes, canners come with a riser, and I had it in place for the pasteurization. Without it, I'm sure the risk of bombs would be much higher.

I left a normal amount of headspace, approximately 1.5" in longneck bottles (estimate from memory). The bottle that exploded did get filled significantly higher than the others, which explains its early failure.

Has anyone tried this on an entire keg? You could place a whole vented keg in a brew kettle and bulk pasteurize...and reason this wouldn't work?

would probably work fine, but I'd worry about the rubber boot on the bottom of the keg getting damaged and/or falling off in the heat.

You thinking of doing this for kegged soda, or do you just not drink your homebrew quickly enough?

I am planning to make another batch of hard cider for the coming holidays. Last year, I back-sweetened after a a long fermentation/secondary and a campden/sorbate treatment before racking into the sanitized original 1gal. jugs.

After a few days, there was pressure building up in the jugs because of another fermentation. Wasn't a big deal because we drank in within a week, maybe it just tasted a bit different because of the yeast growth, but it was still tasty.

This year I was planning on fermenting 3gal. then racking it onto another gallon, then re-filling the jugs. Immediately after that, I plan to place the jugs in a large cooler, and fill the cooler with near boiling water. This should pasteurize the cider to prevent the extra fermentation this year. I could easily just crack the twist off caps a little to release pressure, and then seal before cooling so that not much air gets sucked back in.

Any thoughts on this process?

Thanks,

mthompson said:

I am planning to make another batch of hard cider for the coming holidays. Last year, I back-sweetened after a a long fermentation/secondary and a campden/sorbate treatment before racking into the sanitized original 1gal. jugs.

After a few days, there was pressure building up in the jugs because of another fermentation. Wasn't a big deal because we drank in within a week, maybe it just tasted a bit different because of the yeast growth, but it was still tasty.

This year I was planning on fermenting 3gal. then racking it onto another gallon, then re-filling the jugs. Immediately after that, I plan to place the jugs in a large cooler, and fill the cooler with near boiling water. This should pasteurize the cider to prevent the extra fermentation this year. I could easily just crack the twist off caps a little to release pressure, and then seal before cooling so that not much air gets sucked back in.

Any thoughts on this process?

Thanks,

Click to expand...

sounds good, but you may wanna do some quick calcs to make sure you hit your temp. the gallon jugs will take quite a while to come up to temp, so if you just wing it, you may think everything's ducky but the interior of the jugs is still cool. maybe throw a control jug in there with water at the same initial temp as the cider, and put your thermometer probe in that.

PintOfBitter said:

the gallon jugs will take quite a while to come up to temp...maybe throw a control jug in there with water at the same initial temp as the cider, and put your thermometer probe in that.

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Yeah, I was just going to do periodic checks of the jugs, and start timing when the temp is right. I am shooting for 60-65°C and depending on what I reach, I'll let them sit for the correct amount of time, then cool.

Now I have to figure out the temperature tolerances of the plastic jugs...my guess is they are fine because they are already pasteurized.

Thanks,

I'm interested in pastuerizing my cider also. Just getting ready to try some experiments and this thread is great. How long do you hold your cider @160 degrees.

This may sound foolish but I was talking to someone who pastuerizes their cider in the dishwasher? Have you heard of that one? I would think that the water temp would damage the flavor of the cider but they claim it doesn"t. Anyone know the temp of dishwashers?

very interesting.....

RugenBrau said:

I'm interested in pastuerizing my cider also. Just getting ready to try some experiments and this thread is great. How long do you hold your cider @160 degrees.

This may sound foolish but I was talking to someone who pastuerizes their cider in the dishwasher? Have you heard of that one? I would think that the water temp would damage the flavor of the cider but they claim it doesn"t. Anyone know the temp of dishwashers?

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My brother works in a restaurant, and he says that dishwashers are actually sanitizers. The main difference between the one at his work and the one at his house is that at his work it's a lot hotter, so it needs less time.

The variable is that if something is not clean, it can't really be sanitized. This is true even of autoclaves and medical equipment. If you are sanitizing/killing bugs on the inside of the bottle, where it never touches the dishwater, this is less of a big deal.

If you can just put full bottles in the dishwasher and run it to pasteurize, that is frickin' awesome. I'm going to try that!!

Justibone - Did the dishwasher trick work? Or did you end up with bottle bombs in the washer?

Scratch that question. Searching for "dishwasher pastuerization" did the trick.
Darn newbie gotta hit the search first!

I haven't brewed another sparkling brew since then, so I don't know if it will work or not.

Make sure you check your dishwasher. Mine only got to 135 degrees. I've been putting mine into a large pressure cooker(WITH THE BLOW OFF SEAL REMOVED) and holding it at 160 for 20 minutes.

i did about 4 cases of cider in my dishwasher and i havent had any issues. The cider tasted funny the first couple days but after it sat for about 2 weeks the apple flavor came out more. I would always pasteurize this way from now on. Granted i dont know anything about my dishwasher. Its about 15 years old and a kenmore portable i bought it off a friend, but it gets real hot and i use hot water coming out of my faucet which gets to about 155 degrees anyway. It worked great and my cider is great. (did i mention that already) So i say big yes to dish washer pasteurization.

i made this for beer and must work for cider, i put beer bottles in my BK filled with water, warm the water at 73 celsius degrees, wait for 10-30 min, drain the hot water, add water at room temp (use a hose to fill the BK from the bottom) wait 10-20 min, drain the water, add cold water around 10 celsius degrees, wait 10-20 min (fill from the bottom) drain the cold water. So you have to have your bottles well capped because co2 expands with warm temps also use new bottle if you can they resist more pressure.


this was an experiment at the beggining but i got an overcarbonated beer (by some gusher critter) so i vent the excess of co2, i recapped, and i pasteurized them and works very welll overcarbonation stopped.


I have made blackberry,reapsberry liquor or wine but i boil the juice i add cane or fructuose sugar, i chill the liquid and add yeast, do you guys boil you juice? with these liquors i have had good results very yummy beverages i got and im not supporting sulfites and that stuff as many i like to be natural hehe

Just had a thought after reading these posts. My nephew wants a sweet apple pie cider. Rack to a keg, cold crash, bottle and bring the temp up slowly. Oh yes, he wants it carbed. Why can't I use my MLT with a flat false bottom, recirculate the 160F water for a half hour or so?

Bokonon said:

Here's some quick info:
at 53C minimum time to kill population 56 min
at 60C minimum time to kill population 5.6 min
at 67c minimum time to kill population .56 min

Click to expand...

To elaborate, this is based on a calculation of pasteurization units.

Pasteurization units are calculated as follows, where T is the temperature in °C:
PUs = minutes * 1.393^(T - 60)

The times Bokonon listed were the times/temperatures necessary to achieve 5.6 pasteurization units. This is a common number, but some breweries go for more and some less.

PUs below 60°C may not be accurate (heating to 40°C for 3 days would give you food poisoning instead of pasteurizing). And PUs will not be applicable to microbes unless they are killed around 60°C, so it's better not to have any infection in the first place.

PintOfBitter said:

I understand your line of reasoning, but I think that the increase in pressure in the bottles due to CO2 expansion would far outweigh the increase in pressure in the canner due to heating. Not sure, but that was my assumption. I didn't have any good info for the solubility of CO2 at different temps.

Click to expand...

Bingo. Or perhaps BANG-o

Here are a few online calculators for Pasteur Units (PUs) for beer and juices that also let you calculate headspace pressure at target temp for a given carbonation level:

https://www.interupgrade.com/en/pasteurisation-berechnen

For beer 10 to 15 PUs should be more than enough.

FYI a beer carbed with 5.5 g/l CO2 will give a pressure of 12.4 bar at 70°C. That's a lot of bang, so be very careful.