How long does it take for the karo corn syrup to work?

Karo corn syrup typically starts to work quickly, often within 15 to 30 minutes, depending on the context in which it's used. For baking or cooking, its effects are almost immediate as a sweetener or thickening agent. However, if you're referring to its use in a recipe for a specific purpose, like preventing sugar crystallization, its effectiveness can be observed almost right away during the cooking process.