ginger beer bizarre negative pressure

[gvmsia]

i started making ginger beer 4 weeks/attempts ago. the first 3 batches went relatively well. my method/ingredients were to simmer 2 litres water, 100g sugar, 60g fresh grated fresh ginger, and after cooled added 120ml liquid from the ginger bug, approx 30g ginger pieces from the bug, juice of 8-9 medium sized limes.
when i sieved and bottled the final product after 3-4 days into plastic soda bottles, i left them on the countertop for 24 hours before refrigerating. after that 24 hrs the bottles had expanded slightly and were hard from the pressure built up inside, pushing outwards.

for the 4th batch, the opposite happened!!! after 24 hrs the bottles were skinnier and pushing itself inwards! it had an opposite/negative pressure.

the 4th batch ingredients were mostly the same except increased sugar from 100 to 150g, and juice of 2 lemons instead of limes. the taste was sweeter (as expected), heat from the ginger same, as well as smell & colour. but hardly if any bubbles.

what happened to the 4th batch that caused the different type of pressure?

 

[Abhishek Dewan]

i started making ginger beer 4 weeks/attempts ago. the first 3 batches went relatively well. my method/ingredients were to simmer 2 litres water, 100g sugar, 60g fresh grated fresh ginger, and after cooled added 120ml liquid from the ginger bug, approx 30g ginger pieces from the bug, juice of 8-9 medium sized limes.
when i sieved and bottled the final product after 3-4 days into plastic soda bottles, i left them on the countertop for 24 hours before refrigerating. after that 24 hrs the bottles had expanded slightly and were hard from the pressure built up inside, pushing outwards.

for the 4th batch, the opposite happened!!! after 24 hrs the bottles were skinnier and pushing itself inwards! it had an opposite/negative pressure.

the 4th batch ingredients were mostly the same except increased sugar from 100 to 150g, and juice of 2 lemons instead of limes. the taste was sweeter (as expected), heat from the ginger same, as well as smell & colour. but hardly if any bubbles.

what happened to the 4th batch that caused the different type of pressure?

Few guesses:
You didn’t oxygenate well. The gravity was higher, did you take readings? Usually for 2litres I add 1 cup of sugar. You should refrigerate only after 3-4 days of carbonation done outside. I usually let it ferment for at least a week and then close the cap tightly. I also check for cap tightness everyday as pressure causes the caps to loosen up and result in loss of carbonation. Hope this helps. I also add lime/ lemon zest for flavour. I also add pinch of cream of tartar, Epsom salt and Himalayan pink salt.

 

[gvmsia]

thanks Abhishek. sorry i didnt take any reading coz i'm new to this and dont have any equipment. so correct me if my understanding is wrong. my problems are...

- not enough oxygenation. will stirring once a day fix this?
- not enough sugar. solution: increase from 150g to 1 cup (200g)
- not enough fermentation at the 1st stage. solution: increase from 3-4days to 7+ days
- not enough carbonation at the 2nd stage after bottling/capping. solution: increase from 24 hours to 3-4 days.

 

[Abhishek Dewan]

Hello, you need to oxygenate only before start of fermentation. Shake vigorously for few minutes after adding yeast and that should do. For small batches, you can ferment in the PET bottle itself but remember to burp the bottle thrice a day. After active fermentation slows down (typically a week or so), put the cap tightly and don’t burp. Within 3-4 days it should harden and carbonate nicely. Then keep refrigerated for 24 hours and feel the hardness of the bottle. If it is less, take it out and leave outside to ferment further, else drink it. The advantage of this approach is you don’t run risk of infection and no need to add priming sugar (usually, unless you keep burping beyond a week). Good luck.

 

[gvmsia]

thanks i will tweak my method for the next batch to closely follow your recommendations. i am still puzzled though why my last batch gave the opposite result even though i was doing basically the same steps as previous batches. thanks for your help.

 

[gvmsia]

i'm just wondering... the only ingredient that could have changed so much that would cause a complete opposite reaction would be the ginger bug, right? could it be my ginger bug has changed? what test can i do to the bug to confirm if its ok or not?

 

[Abhishek Dewan]

The ginger bug can be stored in the fridge for generations. I always have mine in the fridge and I take it out every 2-3 weeks and leave on the counter top with some brown sugar or jaggery for the night. In the morning, you can see it bubbling nicely. Unlikely it'll change unless you made a new starter.

 

[gvmsia]

better late than never...here is a video of it...

 

[Abhishek Dewan]

I'm hazarding a guess - yeast trying to suck in oxygen/air. When you heat/boil water, oxygen/air is reduced in it that's how you make clear ice. Maybe you didn't oxygenate it enough before pitching in the yeast. Initial part of fermentation requires healthy dose of oxygen.
Personally something like this never happened to me.