ketchup
Also known as: bottle ketchup
A sweet-tangy condiment made from tomatoes, vinegar, and sugar; used as a table condiment and, in cooking, as a fast source of tomato sweetness and acidity in sauces, glazes, and braises.
Buying guidance
Any standard brand works interchangeably in most cooking; check the label if avoiding added sugar, since ketchup is sweeter relative to its tomato content than most people expect. It has enough sugar to scorch under high heat, so add it later or keep the heat moderate when using it in a glaze.
Substitutions
- Tomato paste plus a little sugar and vinegar -- gives direct control over sweetness and tang; start with about 3 parts tomato paste to 1 part each sugar and vinegar and adjust to taste.
- Barbecue sauce -- works in a glaze but brings extra smoke and spice, so it isn't a neutral swap.
- Tomato sauce reduced with a pinch of sugar and vinegar -- thinner than ketchup, so reduce further or cut back liquid elsewhere.
Tips & common mistakes
It isn't a substitute for tomato paste or plain tomato sauce -- it's much sweeter, thinner, and already seasoned with vinegar and spices, and swapping it in changes both flavor and consistency more than most cooks expect.
Storage
Its vinegar and sugar content make it very shelf-stable refrigerated -- an opened bottle holds its quality well for months. Slight darkening or watery separation at the top of an older bottle is just oxidation, not spoilage; stir it back in.