Q: We switched to an air impingement oven but can’t get a good, balanced bake between the top and bottom of our pizzas. Why?


A: Your question is a fairly common one. I assume you’ve already worked with the baking time and temperature and made sure the oven has been cleaned and operates properly, but the problem persists. Now you need to look at the oven finger profile.

Air impingement ovens are sold with a “stock” finger profile, which is typically full open across the bottom but varied across the top. The top finger profile varies according to the type (gas or electric), size and manufacturer of the oven. Some ovens come with a custom or proprietary finger profile. This feature can be troublesome if you’re working with a used oven—it might have one of those custom finger profiles, which, in all probability, will not be the best for baking your pizzas.

Since there are so many different possible fingers for air impingement ovens, you should first confirm that all of the bottom fingers are fully open for maximum airflow. (This requires removing the conveyor belt, which is not a difficult task and has to be done for routine cleaning anyway.) Then remove the top fingers (being careful to note their respective positions), record the number on each finger insert, and contact the oven manufacturer with this information to see if it conforms to their stock pizza finger profile. If it does, you will then need to discuss with them what changes should be made to the finger profile to achieve the type of bake you are looking for.

If you buy a new oven, manufacturers will make sure it has the correct finger profile for your pizzas. If the oven is used, you may have to swap out fingers to create the best baking profile for your pizza. Some vendors are quite accommodating, while others are not. So remember: Before buying an oven, inspect the top and bottom finger profile and compare it to the manufacturer’s stock finger profile for that oven. This will at least ensure you are buying an oven profiled for pizza rather than baking seafood dishes, and you won’t have to pay the extra cost of changing the finger profile in addition to the cost of the oven!  


Tom Lehmann, Tom Lehmann: In Lehmann's Terms