What characteristics do all acids have?

All acids tend to have a sour taste, for example, vinegar, which contains acetic acid. Acids also turn blue litmus paper red after reacting with the indicator. Additionally, acids conduct electricity after they become dissolved in water and can either be strong or weak electrolytes. When acids react with metals, they produce hydrogen gas as byproducts. They are also able to corrode certain metals such as carbon steel and zinc. Additionally, when acids react with bases, they yield salts and water as byproducts. Lastly, all acids also have a pH lower than 7.