It is a common misconception that Mormons are not allowed to consume caffeine, the limitation is actually on "hot drinks," which is interpreted as having meant tea and coffee specifically in the time it was written down. They still drink soda and other heated drinks such as wassel, hot chocolate, and postum (a morning coffee substitute most folks find absolutely disgusting).

(we live near a de facto Mormon college and pester our neighbors, who are largely Mormon professors, about such things)