Direct Contact Heat Transfer
Simultaneous heat transfer from both sides
shortens process time for products thinner
than approximately 30 mm (1.2 in).
Cooking 11 mm (0.43 in) thick burger patties
on a tabletop requires approximately
4.5 minutes, or slightly more than
2 minutes per side.
When direct contact heat is applied
simultaneously from both sides,
process time is 55 seconds.
Natural chicken breasts weighing 200 g
(7 oz) reach 74°C (165°F) in under
5 minutes, compared with 16 to 24 minutes
in a hot-air steam oven.
Sliced RTE bacon requires 20 to 45 seconds,
depending on the desired level of cook-out,
color and crispness.
55 sec
11 mm burger patties
<5 min
200 g chicken breasts to 74°C
20–45 sec
Sliced RTE bacon
Dry Cooking vs. Wet Cooking
Understanding the effects of steam,
moisture and static dry heat on yield,
browning and product appearance.
Steam is frequently added to the air
in ovens using fans to force air
through heat-exchangers.
Moisture in the closed loop evaporates
when moist air passes through
a heat-exchanger, resulting in drier air.
Steam is added to reduce dehydration,
much as a hairdryer illustrates
how effectively moving hot air
removes moisture.
Adding steam can increase retained yield
for many products. However, wet cooking
does not aid browning.
Steam can wash off marinades and coatings
and generate a pale product appearance.
Static dry heat uses non-moving air
and does not force air and moisture
through heat-exchangers.
Therefore, no additional steam needs
to be added. This avoids associated
steam costs, energy use and interference
with the Maillard reaction.
Dry static air, often combined with
direct-contact heat, supports broiling,
searing and roasting in shorter
process times.