Ovens are the workhorses of the restaurant industry, but different kinds are needed for different restaurants. Choosing the right oven takes time and a bit of research, as you have probably seen what happens when you’ve tried cooking something you’re familiar with in a new type of oven. For instance, an oven great for high-volume bread baking might be terrible for a delicate pastry or a roast.
Convection ovens are a popular option in many restaurants because they allow food to cook faster, more evenly, and at a lower temperature. Yet they do have their share of problems. This guide is meant to help you sort out the facts about convection ovens and help you decide whether they are right for you.
What is a convection oven?
Heat is primarily transmitted in three ways: conduction, convection, and radiation. Conduction is how a stove works. Heat is applied directly to the bottom of a cooking vessel to warm it up. Radiation is how a standard conventional oven works. The heating element transmits heat through the air and absorbed by the objects in the oven. Convection works by the motion of something hot passing something cool. If you’ve ever stood out in a wind you know the effect of convection.
Convection ovens combine traditional oven heating elements with fans to create currents of air within the oven. The radiation from the elements combined with the moving air allows food to cook faster since it is heated by two different methods. Conventional ovens do have some natural convection due to the presence of air inside, but it can also be easily blocked if the oven is very full. A convection oven forces hot air to move despite this.
Some convection ovens have elements on the top and bottom of the oven with fans to assist. Others hide the elements behind the walls of the oven and force heated air through vents into the cooking chamber. In this type, some radiant heat is provided through the heating of the walls. You might also be familiar with impingement ovens. These are special high-speed convection ovens commonly used in the pizza industry to cook large volumes of pizza.
Benefits of Convection over Other Ovens
The primary benefit of convection ovens is that they greatly reduce hot and cold spots inside of the oven. By forcing heat to travel through the chamber by fan, the interior is evenly heated. This has several add-on effects.
First, food is cooked much more quickly. Hot air moving over food combined with the radiant heat from the elements and walls. Cooking times can be reduced by a quarter with a convection oven compared to a standard oven. In a high-volume kitchen this can make a tremendous difference in how fast food can reach customers.
Alternatively, food could also be cooked at a lower temperature for the same amount of time. Depending on the efficiency of your current oven, a convection oven may lower energy costs. For the cook, a lower cooking temperature means less chance of browning the food too much. However, overbrowning can be a major problem for chefs inexperienced with cooking in a convection oven. This can be an especially difficult problem for pastry chefs.
Since the temperature of a commercial convection oven is far more even, this means everything in the oven will also cook more evenly. Large pieces of meat do very well in a convection oven. Convection ovens also render fat very rapidly and create crispy skins.
Another advantage is that you won’t need to rotate food nearly as often. Normally a pan in an oven must be rotated to deal with hot and cool spots. With a good convection oven you can pop in a tray of diced bread and get even croutons. Drying fruit in a convection oven can be done even faster than a dehydrator.
Finally, convection allows more food to be cooked in the same space. Conventional ovens are normally limited to two racks to prevent the food in the oven from creating a cold space. The top element heats the upper rack and the lower element heats the lower. A convection oven removes this limitation.
Choosing the Right Convection Oven
Convection ovens are becoming very popular in the home market. Unfortunately, this is causing some marketing confusion. A true convection oven will generally have three heating elements: the top and bottom elements standard in a conventional oven and a third one in the back near or as part of a fan. Often the fan is covered by a panel. The fan sucks in outside air, blows it over the heating element, and pushes it up into the chamber. Look for terms like “true convection”, “third-element convection”, or “European convection” in marketing descriptions.
Avoid all ovens that have a rear fan but no third element. The third element is necessary to avoid mixing different air temperatures inside the chamber. Without this, you’ll get hot and cold spots within your convection currents. Most countertop convection ovens do not have a third element.
If you are a fan of gas ovens, you’ll need to do research to find out how each model prevents uneven air temperatures inside of the oven. If you’re looking to replace a range, many brands offer a dual-fuel system where gas is used for the stove and electric for the oven.
Another thing you’ll need to watch for is capacity. For best results with convection there needs to be a 2” air gap around the edges of whatever you’re cooking to allow the air currents to flow. If you need to, take a baking sheet or roasting pan and a mockup of the largest thing you expect to cook in your oven when you go shopping. A simple foam block or even cardboard cut and taped together into a box will work.
You will also need to be aware of depth requirements. If you’re getting a stand-alone oven this isn’t as much of a concern, but if you’re replacing a slide-in range then you’ll need to measure both the depth of the unit and the depth of the cooking chamber as well. There is commonly a “bump” at the back of the oven wall where the fan and third element go. You’ll need to make sure the reduction in back-to-front space does not interfere with your pans and sheets.
For commercial convection ovens, Vulcan, Southbend, and Blogett are excellent brands. Blogett is the most highly regarded brand. According to Foodservice Equipment and Supplies magazine, Blogett has won the “Best in Class” award for convection ovens for ten years running. You can find information about these brands at their websites:
- http://www.blodgett.com/products/convection-ovens/
- http://southbendnc.com/convectionovens.html
- http://vulcanequipment.com/products/ovens/
Cost of Convection Ovens
On the whole, convection ovens are more expensive than conventional ovens, but additional features can drive up the costs significantly. Expect to spend $3000 minimum per convection oven, with average prices hovering around $6k-$7k. The highest end Blogett ovens can run over 15k.
The biggest driver of increased cost is capacity, but there are many oven features that can adjust the cost of the oven up or down, including:
- Steam vents for bakery ovens
- Adjustable heat for each element
- Programmable recipes
- Energy improvements. Some models are Energy Star rated.
- Improved seals and locks
- Ability to reach very high heat (important for pizza ovens)
- Ability to turn off convection (this is becoming standard)
- A wide variety of settings for baking and roasting to overcome certain problems with convection ovens (see below)
- Ability to hold food at temperature after cooking
Know what you need your oven to do before shopping around. Also, consider buying an Energy Star rated model. You may be able to receive a rebate for your purchase depending on local laws. See http://www.energystar.gov/rebate-finder for more details.
Where can Convection go wrong?
One major thing to note is that you will need to alter the temperatures and cooking times for all of your recipes. Like any other kitchen tool, you’ll need to get experience with it before using it in your restaurant. Expect a learning curve. Watch for over-drying and over-browning of your food. In general, the thinner the food is the more convection will be an effect in the cooking.
For most food, convection is an excellent way to cook in an oven. However, some foods are much trickier to cook on one. Since the air temperature is mostly constant, it’s very difficult to cook dishes that require a crisp crust and an unburnt top like meringues. Some ovens try to get around that by having adjustable element temperatures.
Convection currents love to blow around parchment paper and disturb batters. One thing you can do if you have to cook pastries on parchment is to put a little dough in the corners to tack it down. Silicone baking sheets are another option. Avoid tin foil. Bits can break off and get into the fan.
Convection ovens lose heat much faster than standard ovens when the door is opened. In a bakery where the oven constantly in operation, the opening and closing of the door can heat the space very quickly. Each time the door is opened it takes time to heat up the oven again.
If baking is your specialty, consider getting a deck oven before getting a convection oven. Deck ovens are specially designed for baking at volume, and have adjustable temperatures for the top and bottom of the chamber. However, they can be far more expensive than a convection oven and many foods cannot be cooked in them due to the narrow space.
Last Words of Advice
Remember that there is no perfect oven. Each type of oven has its own inherent flaws, depending on what you’re cooking. There are, however, ovens suited to certain needs over others. The first step to getting any oven is to do your research on it. Ask around, look at reviews of the models that you’re thinking about, and check out the forums here to see if anyone’s got suggestions.
