Some say it’s madness – others call it pure genius. Marmite and Guinness have joined forces to create a limited edition Guinness Marmite. The glass jar appears black when full, and together with the white lid (to replicate a pint of Guinness) is set to be a must-have for collectors of cool. With just 300,000 jars being created and only on sale for around six to eight weeks, Guinness Marmite is set to fly off the shelves. The special recipe uses 30% Guinness yeast (a specific strain of yeast used only to make the iconic Irish stout), giving it a subtle, yet distinctive Guinness flavour, without the alcohol. 250g jars of Guinness Marmite are priced £2.49 RRP.