Albrecht reportedly died last Wednesday in the town of Mülheim an der Ruhr, but reports of his death first surfaced Monday in the Frankfurter Allgemeine and Süddeutsche newspapers. His company later confirmed the news.
"We mourn the death of our company founder, Karl Albrecht," it said in a statement.
Born and raised in the western city of Essen, he and his brother Theo learned the grocery store trade working in their mother's supermarket. During the Second World War, Karl served in the German army. Afterwards, the famously media-shy brothers took over their mother's business.
Karl founded discounter grocery store chain Aldi together with his brother Theo in 1960. The company then split into north and south supermarket chains. Theo ran Aldi Nord, while Karl took charge of Aldi Süd.
The so-called "Aldi equator" runs between Essen and Mülheim, where Aldi Süd is headquartered.
Theo, two years younger, died in 2010.
Today, Aldi Süd employs some 35,000 workers at around 18,000 different locations.
Albrecht had an estimated personal wealth of 19.15 billion euros ($25.9 billion), according to Forbes magazine.
Aldi chains can be found in Austria, Belgium, the Netherlands, France, Spain, Portugal and the United States, among other countries.
dr/pfd (AFP, Reuters, dpa)