Guinness has sifted through the archives to find recipes dating back more than 200 hundred years for their latest brews.
The Guinness Dublin Porter (1796) and the Guinness West Indies Porter (1801) will be available to buy in selected bars and shops from the beginning of next month.
The head of innovation for Guinness, Nick Curtis-Davis, said that now was the perfect time to invest in new beers.
"If you look at the world of beer, all of a sudden people are excited about craft beer and it's the right time to explore the depths of our archives and find some treasured recipes.
"What we're seeing is people are just reacting to a mainstream society and the gap between the producer and the consumer is shortening," added Mr Curtis-Davis.
The Guinness Dublin Porter is inspired by the idea of quenching a working man's thirst at the end of a long hard day.
The Guinness West Indies Porter was originally created to withstand long-distance voyages while always retaining its freshness.