Carlsberg is a Danish brewing company founded in Copenhagen in 1847. It was started by J.C. Jacobsen and named after his son Carl. The pH scale, the standard measurement of acidity, was developed in Carlsberg’s laboratories in 1909. It is currently the world’s fourth largest brewing group. Carlsberg sells 114 million bottles of beer every day across more than 150 markets. The company began exporting beer in 1868 and one hundred years later opened its first overseasbrewery, in Malawi. It currently has dozens of different brands in many countries. Its most famous products are the Carlsberg lager, Special Brew (which has a 9% alcohol content) and Elephant beer. Carlsberg has been involved in some memorable advertising, using the slogans "Probably the best beer in the world".