...are made from using the entire fruit, except the pits (though sometimes a few slip through!) Usually citrus, or a combination of fruits with citrus, true marmalade, as it originated in Spain and Scotland, is very thick, dark, and intensely piquant, with a bitter ‘edge.’ At least two days of preparation and cooking over low heat, stirring nearly continuously, goes into making each batch: literally “keeping an eye on the pot” as it cooks down to a lush density almost too thick to ladle into the jars.