Kombucha Bottle Bombs?

[trav77]

I'm just about to get myself a scoby and give kombucha brewing a shot. Brewing the sweet tea and the primary fermentation seem pretty straightforward but I wonder about bottling and secondary fermentation.

Most of the recipes I see online recommend adding flavourings (juices, fruits, etc.) at bottling time and refermenting in the bottle to carbonate. Given that the amount of fermentables being added at bottling will vary greatly depending on what/how much is being added, doesn't that pose a risk of bottle bombs or at the very least unpredictable carbonation levels?

The process is in pretty stark contrast to typical beer practice where we ferment out to FG, then add a measured amount of sugar to achieve a predictable level of carbonation.

 

[snarf]

..., doesn't that pose a risk of bottle bombs or at the very least unpredictable carbonation levels?

Yes, indeed it does!
That's why it's usually recommended to refrigerate the bottles after a couple of days, if you use this method.

 

[trav77]

Yes, indeed it does!
That's why it's usually recommended to refrigerate the bottles after a couple of days, if you use this method.

Yeah there are an awful lot of kombucha bottle bomb stories out there on the interweb.

I guess I was wondering if anyone tries to be more precise by fermenting to terminal gravity then adding a measured amount or sugar to referment in the bottle (a la beer brewing). But from what I've also read the fermentables in kombucha aren't 100% attenuated at bottling usually anyways, correct? So maybe that's not really a viable option and using thick bottles + refrigeration is really the only method.

 

[snarf]

If you let the kombucha ferment until all the sugar is gone, it's pretty sour. That's why most people bottle before it gets too acidic.
Personally I let my kombucha ferment for a bit longer than is usually recommended and then bottle in champagne bottles (without adding sugar). The brew takes a bit longer to get carbonated (a couple of weeks up to 2 months at room temperature), but on the other hand, I don't have any experience with bottle bombs...

 

[Owly055]

I'm just about to get myself a scoby and give kombucha brewing a shot. Brewing the sweet tea and the primary fermentation seem pretty straightforward but I wonder about bottling and secondary fermentation.

Most of the recipes I see online recommend adding flavourings (juices, fruits, etc.) at bottling time and refermenting in the bottle to carbonate. Given that the amount of fermentables being added at bottling will vary greatly depending on what/how much is being added, doesn't that pose a risk of bottle bombs or at the very least unpredictable carbonation levels?

The process is in pretty stark contrast to typical beer practice where we ferment out to FG, then add a measured amount of sugar to achieve a predictable level of carbonation.

I have a simple, 100% effective method of preventing this. I use 1 Liter EZ Cap brand beer bottles, which by the way are rated at over 100 PSI. These are a Grolsch type bottle but much better quality. Using a standard size 64 rubber band, I pass it through the bail, and loop it through itself like half hitch. I then stretch it down under the bottom of the bottle holding the bail down with it's tension instead of latching the bottle. This allows the gasses to vent, but retains plenty of pressure for carbonation. With kombucha, I add home made bottling syrup, and give it anywhere from about 3 days to a week to carbonate.
I've been doing this for quite a few years. It's a very effective and safe system. My original system involved two pieces of lumber, and a spring connecting them. The bottles sat in a recess in one piece of lumber, and the other laid on top with the spring drawing it down. The bottles...... also EZ caps were not latched.

H.W.

 

[trav77]

I have a simple, 100% effective method of preventing this. I use 1 Liter EZ Cap brand beer bottles, which by the way are rated at over 100 PSI. These are a Grolsch type bottle but much better quality. Using a standard size 64 rubber band, I pass it through the bail, and loop it through itself like half hitch. I then stretch it down under the bottom of the bottle holding the bail down with it's tension instead of latching the bottle. This allows the gasses to vent, but retains plenty of pressure for carbonation. With kombucha, I add home made bottling syrup, and give it anywhere from about 3 days to a week to carbonate.
I've been doing this for quite a few years. It's a very effective and safe system. My original system involved two pieces of lumber, and a spring connecting them. The bottles sat in a recess in one piece of lumber, and the other laid on top with the spring drawing it down. The bottles...... also EZ caps were not latched.

H.W.

Awesome. I'll give that a shot as I'm not too keen on even taking a chance on bottle bombs.

 

[Morden2004]

I've been bottling for more than a year using plastic beer bottles (1 litre) and I've yet to have a bottle bomb. I ferment the booch to just shy of sour, add my flavouring and 2 table spoons of sugar to my 20 litre batch and bottle immediately. I wait 2 days then test open 1 bottle to test the co2 level. It usually takes 3 full days at 72F room temp to get the co2 level where I like it.

Paul

 

[GregP507]

Yes, indeed it does!
That's why it's usually recommended to refrigerate the bottles after a couple of days, if you use this method.

I'm using 2 liter plastic bottles which can swell up a bit when the cap is too tight, but they don't generally explode. The worst I've seen is a friend who started a batch, and went to the hospital for a week. The batch was ruined, but it didn't explode the bottle; it swelled up like a football, that's all.

 

[mr_stout]

I'm using 2 liter plastic bottles which can swell up a bit when the cap is too tight, but they don't generally explode. The worst I've seen is a friend who started a batch, and went to the hospital for a week. The batch was ruined, but it didn't explode the bottle; it swelled up like a football, that's all.

Why did he go to the hospital? What does that have to do with a bottle that did not explode?

 

[GregP507]

Why did he go to the hospital? What does that have to do with a bottle that did not explode?

What I could have said, more simply, is that he went away for a week, leaving the bottle unattended. The hospital visit is unrelated to the anecdote.