The action of the yeast is stopped by cold, which is why it is necessary to ferment in ambient air.
Be careful to use plastic bottles and do not fill them completely as gas will form and the bottles may explode. Also be careful when opening the bottle after fermentation so as not to splash yourself.
You can keep your Ginger Beer for two to three days in a cool place in a tightly closed bottle, but once opened, it is better to drink it more quickly because it tends to lose its gas.