How to add sugar to Carbonated Water without decreasing the Carbonation?!

The problem is stirring. Stirring releases the suspended carbon dioxidel

If you use a syrup instead of granulated sugar, it will work better. Either buy a flavored soda syrup or make a simple syrup (heat equal amounts of sugar and water until the sugar completely disolves into the water and the solution looks clear). Chill the syrup and use as needed. A simple syrup can be used to make italian ices, sweeten soda, moisten cakes and many other uses. It will last a few weeks if refrigerated. I usually make a quart at a time although I usually use it for italian ices. My kids sometimes make sodas with it.

It's the edges of the crystals that create what is called a "nucleation point" that allows CO2 gas to be easily released from the water when you add the sugar.

This is the principle behind the Diet Coke and Mentos trick - where you turn a soda bottle into a fountain of soda.

The way to prevent is to not use dry sugar - use a sweet liquid to sweeten your drink. You can make simple syrup by heating one cup of dry sugar and one cup of water in a pan until the sugar dissolves, then cool and keep in the fridge. When you add this to the drink, it won't fiz up.

If you were making your own soda water at home with something like a soda stream, then the option would be to sweeten the drink first and THEN add the carbonation.

I hope that helps.

Mark is correct. It will also help if you chill the carbonated water as close to 32 degrees F as possible because the warmer it is the faster the carbonation is released.