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The Science Behind Combi Cooking: Steam, Convection & Magic

The Science Behind Combi Cooking: Steam, Convection & Magic

Erin McGill |

In a professional kitchen, precision is everything. Whether you’re baking delicate pastries, roasting meats, or bulk-cooking vegetables, you need consistency, speed, and control. That’s where combi ovens shine, combining steam, convection, and a touch of culinary “magic” to deliver results that traditional ovens simply can’t match.

Let’s break down the science behind why combi cooking is revolutionizing modern kitchens.

What Is a Combi Oven?

A combi (combination) oven uses three cooking modes:

  1. Convection (Dry Heat)
    A fan circulates hot, dry air evenly around the chamber — great for roasting, baking, and browning.

  2. Steam (Moist Heat)
    Pressurized steam surrounds the food, preserving moisture and nutrients — perfect for vegetables, fish, and rice.

  3. Combi Mode (Mixed)
    The magic happens here: precise blends of heat and steam allow for faster cooking, less shrinkage, and superior results.

The Science at Work

Convection = Consistent Dry Heat

Standard ovens heat from one or two sources. But convection ovens use fan-driven airflow, ensuring even temperature throughout. This means:

  • Faster cook times

  • Even browning and crisping

  • Better colour and texture control

Steam = Moisture Retention

Steam transfers heat faster than dry air. Why?

  • Water vapor has a higher heat capacity than air

  • Steam surrounds food on all sides, penetrating quickly

  • It prevents drying, meaning juicier meats and vibrant vegetables

Combi ovens generate steam using either:

  • A boiler (generating steam outside the chamber)

  • An injection system (spraying water directly onto hot elements)

Combi Mode = Precision Balance

In combi mode, the oven monitors:

  • Humidity levels

  • Chamber temperature

  • Food temperature (using core probes)

By precisely adjusting humidity and dry heat, you can:

  • Bake croissants with perfect flake and rise

  • Roast meats that are crisp on the outside, juicy on the inside

  • Regenerate pre-cooked meals without drying them out

Why Combi Cooking Is a Game Changer

Faster Cooking Times

Steam accelerates heat transfer. When combined with convection, cooking can be up to 30–40% faster than traditional ovens.

Better Yields

Dry ovens shrink proteins by up to 25%. Combi ovens reduce that to 10–15%, preserving weight (and profit).

Consistent Quality

Pre-programmed settings and climate control mean every dish is cooked the same, regardless of who's at the controls.

Healthier Cooking

Less fat needed, more nutrients retained. Perfect for hospitals, schools, and health-forward kitchens.

Smart Controls: The Modern Twist

Today’s combi ovens (like Rational iCombi or Unox ChefTop) include:

  • Touchscreen interfaces

  • Auto-cleaning cycles

  • Recipe programming

  • Remote monitoring

These aren’t just ovens,  they’re intelligent kitchen assistants.

Final Thoughts

Combi ovens aren’t magic, they’re just smart engineering built for chefs who demand more. By combining steam and convection, they unlock new textures, flavours, and efficiencies that traditional cooking methods simply can’t match.

Whether you're running a café, restaurant, or institutional kitchen, combi cooking is no longer a luxury — it's a necessity.

Thinking of upgrading?
At Catercombi, we supply, install, and service the UK’s leading combi ovens. Talk to our team to find the perfect fit for your kitchen.