Sometimes known as London Major, Lord Derby is still grown commercially today. The tree produces lavish crops of initially shiny green fruit that later bulge and become golden yellow, sometimes with russet patches. They are fine to use in October when still green, usually with plenty of brown sugar as the younger fruit are very acid. Taking some of the earlier fruit like this will keep your tree cropping well into December. The flesh of the mature yellow fruit is softer and slightly sweeter, with a delicate grain that holds its shape after baking.