Actually, Chilly, my ante-penultimate batch was made in November/December simply from common or garden oranges plus lemons, grapefruit and a couple of limes. Reason was that Sainsbury's were selling off surplus and soon to expire stocks at silly prices; as I can resist anything except temptation I came home with an inordinate amount. The marmalade turned out as good as any other batch. Sure, Sevilles are the right choice (more pips if less juice) but not an absolute requirement for waiting until everybody else is being creative. Maybe this should be a sticky?