Katra wrote:

> Or use a soda pump.
> They have a pump cap now where you can put a cap on it and pump pressure
> into a bottle to prevent anymore "flattening" of the carbonated product.
>

Those don't work. Pumping air into the bottle won't hold the CO2 in
solution. If you want a scientific explanation of why not, look up
"partial pressures".

Best regards,
Bob