In rec.food.cooking, aem > wrote:

> Not much mystery here, is there? Lid down, higher temp, shorter
> cooking time. Lid up, lower temp, longer cooking temp. Especially in
> cold winter air. What am I missing?

Things are not always as simple as they seem. Using a weber kettle, the
coals radiate much less heat, at a lower temperature, with the top on.
This is because the top severely restricts the airflow.

When I want HOT coals, I leave the top off. When I want moderate (pretty
much perfect for most stuff) coals, I put the top on for a while.

Note that I am talking about the radiant heat from the coals. Obviously,
the top increases the trapped heat, and therefore the amount of
convective heat surrounding the food.

So for searing, or for thin cuts, top off. For thicker cuts, top on.

--
In the councils of government, we must guard against the
acquisition of unwarranted influence, whether sought or unsought,
by the military-industrial complex. The potential for the
disastrous rise of misplaced power exists and will persist.
-- Dwight David Eisenhower