What does glucose do to cake icing?

Glucose doesn't directly "do" anything to cake icing. However, it's often added to cake icing for these reasons:

* Moisture: Glucose is a humectant, meaning it attracts and holds moisture. This helps keep the icing soft and prevents it from drying out and becoming brittle.

* Gloss: Glucose adds a beautiful shine and gloss to the icing, making it look more appealing.

* Flavor: Glucose has a subtle, slightly sweet flavor that enhances the overall taste of the icing.

* Stability: Glucose can help to stabilize the icing, preventing it from separating or becoming runny.

* Sugar replacement: Glucose can be used as a partial replacement for granulated sugar, reducing the overall sweetness and adding a unique flavor profile.

It's important to note that glucose is not a direct substitute for sugar in icing. While it can partially replace sugar, it will affect the texture and sweetness of the icing. If you're unsure how much glucose to use, start with a small amount and adjust based on your desired outcome.