Birrell's on South Street, St Andrews, sold fresh fruit and vegetables and delicatessen items. Crucially, it also sold wines, and was the main supplier for student parties. Of special interest were the fortified wines that it sold from huge barrels on high, with taps from which the staff would fill containers you took along. They would sell these wines by the gallon. We kept plastic flagons that had once held cider to fill with their sherry. They sold good sherry by the bottle, but from their casks came a brown, sweet sherry, good enough for students and maybe elderly ladies, but not for much else, and the other was a paler and drier sherry, a little more expensive. We called them BSU, which stood for Birrell's Special Unlabelled.
They came in those two varieties, the first of which we called "El Grotto" because it was grot, and the second we dubbed "El Goodo" because compared to the first one, it was relatively good. At a party we held we served the first. A student friend, Robert Jones, who later became a government minister, asked us next day what was the nice sherry we served. We told him it was El Grotto from Birrell's. It caused much merriment when he later told us that Birrell's had never heard of it. He'd gone there and asked for some El Grotto, not realizing that this was our nickname for the grot stuff.