After many searches on the Google, I still can't find out how to make club soda. So, I have to ask the question – what is club soda exactly?
I bought a iSi Soda Siphon and have figured out how to make carbonated water (finally).
Now what do I have to do to make club soda? How about seltzer?
Best Answer
Seltzer and carbonated water are the same thing. Club soda is slightly different. "Seltzer" comes from German:
So, the primary difference is that seltzer has no added ingredients, but club soda does:
Here's a decent review of the ingredients list and taste of various types of fizzy water.
So to answer your question directly, you can make seltzer just by carbonating regular tap water, and you can make club soda by adding potassium bicarbonate, potassium sulfate, or baking soda to water and carbonating it.