Royal Swedish Opera

Gustave III who was assassinated here in the opera is also famous for his coffee experiment. Gustav III, who viewed coffee consumption as a threat to the public health and was determined to prove its negative health effects, ordered a scientific experiment to be carried out. The king ordered the experiment to be conducted using two identical twins. Both of the twins had been tried for the crimes they had committed and condemned to death. Their sentences were commuted to life imprisonment on the condition that one of the twins drink three pots of coffee, and the other drink the same amount of tea, every day for the rest of their lives. Two physicians were appointed to supervise the experiment and report its finding to the king. Unfortunately, both doctors died, presumably of natural causes, before the experiment was completed. Gustav III, who was assassinated in 1792, also died before seeing the final results. Of the twins, the tea drinker was the first to die, at age 83; the date of death of the surviving coffee drinker is unknown.