Why Microwavable Foods Often Tell You to Microwave Something That Shouldn't Be

Have you ever picked up a microwavable frozen meal and noticed the instructions warn against microwaving certain components? It's a strange and sometimes frustrating practice, but there is a reason behind these seemingly contradictory instructions. Understanding the science and technology behind microwavable foods can help demystify why the instructions are the way they are.

The Mystery of the Microwave Instructions

When you’re browsing the frozen food aisle, you might come across a packaged meal with a label that reads something like this:

Blend the pasta separately. Do not microwave.

This is a strange way to ask it. Why is it that something shouldn’t be microwaved? The makers of microwavable food know how their food works, and they wouldn't use confusing or contradictory instructions unless there was a valid reason.

Why Foods Can't Be Microwaved in Their Packaging

Some foods, particularly those with certain packaging materials or coatings, might not be safe to microwave in their current state. For example, pies are often mentioned in these instructions. Typically, the crust of a pie is not designed to handle the heat produced by a microwave, and it can become soggy or burn. However, with the proper packaging, the coating on the packaging is designed to heat up and make the crust crisp. This is why the instructions might say not to microwave the pie as is, but to place it in the microwave with the correct packaging in place.

Understanding the Packaging's Role

The packaging of microwavable foods plays a crucial role in the heating process. Many manufacturers use special coatings on the packaging to achieve specific heating outcomes. For instance:

Heating Coatings: These coatings are designed to heat up and apply heat to particular parts of the food. In a pie, these coatings can be used to heat the crust, making it crispy and delicious.

Moisture Barriers: Packaging may contain special barriers that are designed to keep moisture out during the heating process, ensuring the food remains crisp.

Temperature Control: Some packaging materials and coatings may be designed to handle higher temperatures better than others, providing a safer and more effective heating experience for the user.

Common Foods That Require Separate Heating

There are several types of foods that often require separate heating or the removal of certain components before microwaving. Here are a few examples:

Pies: As mentioned, pies are often noted as requiring separate heating due to the crust not microwaving well.

Sauces and Sauces with Gloves: Some sauces are coated with a protective layer that might not be suitable for microwaving. The coatings can prevent the sauce from getting hot or can cause it to burn.

Certain frozen desserts might have toppings or coatings that can interfere with the microwaving process, and they often require separately microwaving the cake and topping.