Many people buy a toaster oven so that they don’t have to turn on their energy hogging full-sized oven for small meals. Then, to their dismay, they notice that most prepackaged frozen meals have this warning: “Do not cook in a toaster oven.” These countertop ovens are just smaller versions of normal ovens, so is it really a bad idea to cook frozen meals in them?
First, lets look at the differences between toaster ovens and full-sized conventional ovens. Both produce dry heat and in general, both have the same temperature range. The method of heating varies from oven to oven, with conventional models using either gas or electricity as the primary energy source. Toaster ovens rely solely on electric heat, but this is no different from many regular ovens out there. So why would you not be able to cook a frozen meal in a toaster oven?
I had some idea of why this would be, but rather than rely on conjecture I went straight to the source. I contacted four major companies whose products warned against using a toaster oven. All four gave me the same answer: uneven and unpredictable heating could lead to improperly cooked food. This can lead to food poisoning.
I have tested many toaster ovens throughout the years and I can tell you that they do not all have uneven and unpredictable heating, but many do. The issue with many is a discrepancy between the heat setting and actual internal oven temperature. You may have set the oven to 375 degrees F as directed by the package instructions but have an actual temperature of much less than that. This is especially true with cheap models that are poorly insulated. This can lead to undercooked foods which can be dangerous to consume.
Is there a way around this problem? There certainly is! Accurate instant-read thermometers are easy to find and inexpensive. Many have probes that can be left inside the oven while it is in use. This will allow you to ensure the internal oven temperature is where it needs to be. This will take care of any issues regarding unpredictable heating or temperature.
Uneven heating is much more difficult to overcome. Many inexpensive toaster ovens cook food very unevenly, leaving some portions of the food burnt while others are raw or undercooked. This isn’t just a problem with frozen meals; it is problematic with anything you cook. The problem is just amplified when you start with a product that is frozen rather than room temperature or close to it. I would never attempt to cook a frozen meal in an appliance that has issues with uneven heating. I would also not want to use that appliance for any of my other cooking needs.
So is it safe to cook a frozen meal in a toaster oven? I would say the answer to that is “maybe.” You probably should not risk it unless you are absolutely sure the appliance you are using cooks things evenly …