Drinking carbonic acid excavated from the refrigerator. In many cases, I was completely disappointed.
I found an item that prevents this at the 100-yen shop Daiso. Its name is "Carbonic acid escape plug".
The usage is as follows.
Remove the lid of the carbonated PET bottle that is being drunk and attach this product.
While holding the bottle, move the pump up and down to compress the air inside the bottle. It feels like a bicycle pump.
OK if the bottle is a little hard. After that, leave the cap part, remove the pump part, and store it upright in the refrigerator.
Repeatedly the bottle will become a little stiff
Store upright in the refrigerator
After leaving it for a week and drinking it, I enjoyed the crisp and stimulating carbonic acid. For those who often do not drink all at once, such as using only a small amount as a split material for sake, why not try it.