Calculate max pressure during fermentation?

[whoaru99]

Made a couple small batches of ginger beer where in there is about 30oz of the concoction in each 1L plastic bottle (used carbonated water bottles).

There is 6oz of simple syrup in each bottle. Cane sugar 1:1 water.

Primed each bottle with CBC-1 yeast.

These bottles were getting ROCK hard and I was burping them every several hours until I put in the fridge to slow things down.

Curious if there is any way to calculate approximate max pressure that could develop in those bottles, presuming they had unlimited burst pressure (which of course they don't).

 

[Broken Crow]

So..is it fermenting in these bottles? From looking online to find out the max pressure that PET soda bottle can take before blowing up, I've seen varying reports from 90psi to 126psi..
IF you have those marvellous Kegland carb-caps (which can leak above 45 psi) and some spare EVABarrier and duotight tees, and a doutight spunding valve, you can chain them together on a spunding valve and obsrve the pressure and set the spunding valve below the risk threshold.
Just a thought.

 

[doug293cz]

Made a couple small batches of ginger beer where in there is about 30oz of the concoction in each 1L plastic bottle (used carbonated water bottles).

There is 6oz of simple syrup in each bottle. Cane sugar 1:1 water.

Primed each bottle with CBC-1 yeast.

These bottles were getting ROCK hard and I was burping them every several hours until I put in the fridge to slow things down.

Curious if there is any way to calculate approximate max pressure that could develop in those bottles, presuming they had unlimited burst pressure (which of course they don't).

Yes, it is possible, if you know exactly how much fermentable sugar you start with, the volume of liquid, the volume of the headspace, and the temperature. In a mostly full PET bottle, it would be enough to burst the bottle (or blow the cap off) if the high CO2 concentration and pressure don't kill the yeast before fermentation is complete.

Brew on

 

[MaxStout]

6oz of 1:1 simple syrup into a 1L bottle? You might want to put those bottles into a container to catch stuff if they blow up. Like a 5 gal pail.

 

[mac_1103]

You might want to put those bottles into a container to catch stuff if they blow up.

The Brewer's Friend priming calculator only goes up to 6 volumes. Looks like there's at least 5x that much sugar in each one of these bottles. Keep burping those babies. Or better yet, just leave the caps loose.

 

[MaxStout]

 

[whoaru99]

I did play around with the caps a bit, and with a bit of futzing how tight they're screwed down, one can establish a quasi relief valve.

It does not take much if any further tightning of the cap beyond "first contact" to get a seal that will maintain some pressure firmness but not be concerningly hard.

 

[mac_1103]

So is the goal to ferment most of the sugar for alcohol and then tighten the caps near the end to carbonate? You might find this thread interesting.

 

[whoaru99]

So is the goal to ferment most of the sugar for alcohol and then tighten the caps near the end to carbonate? You might find this thread interesting.

Frankly, it was a quick "just do it" project following a recipe and I failed to up front consider the ramification of that much sugar, and the recipe did not make any mention of alcohol to jog my reality.

My intent was not to produce dry beer per se, rather I went in thinking just bottle conditioning to get fizzy ginger "beer" soda aka Goslings, Reed's etc.

When I saw the level of activity it suddenly dawned on me the potential of the situation.

I'm expecting the first taste to be eye opening as in each 30oz is also 2oz fresh grated ginger root.