M&S St Claritas is brewed for the M&S range by Harbour Brewing Co, based in North Cornwall. The recipe uses spring water drawn directly from the brewery's farm in Lanivet, giving it a specific provenance unusual for a retailer own-label beer. The style is golden ale, with a profile described by M&S as malty and citrusy with a measured bitterness. St Claritas sits within the M&S 'St' beer series, a range that also includes full-strength counterparts, marking it as the low-alcohol entry to an established brand line.