What is a dirty soda? Originating in Utah in 2010, "dirty soda" became a custom daytime drink made from a mix of name brand sodas and flavored syrups. The concept of making sweet, non-alcoholic concoctions became most popular within the Mormon community as rules against drinking alcohol or caffeine made soda the common base for creative and appropriate mixology. Shops like Swig, which just specialize in dirty soda, started to establish as drive-thrus all across the West Coast.