Loose the terracotta plate
Cover the waterpan with foil
Would you please elaborate on this. I go round and round with using a water pan with and without and a terracotta plate.
I'll try, until swamprb steps in again.
The original purpose of the water pan (when filled with hot water or sand) is to act as a heat sink, to help stabilize temperature swings. The density of a terra cotta (clay) pan, also filled with water or sand, is meant to serve the same purpose. If you have a WSM (real one, not mini WSM) then you shouldn't need a terra cotta pan, right?
Weber began to include a deeper water pan on the 18 a few years ago, for more water capacity/longer cooks. Similar in capacity to a 15" Brinkmann water pan which can be swapped out on the older 18" WSMs,
http://www.amazon.com/Brinkmann-812-0002-0-Charcoal-Discontinued-Manufacturer/dp/B0049EYYCS << be careful, build quality/paint quality on those isn't great.
So yes, opinions, methods, vary about whether or not you should use a water pan for water. But I don't see why you'd use one
with a terra cotta pan.
My opinion is that a WSM often seals poorly unless you either: 1) have a new one that hasn't yet had anything get bent 2) have an old one sufficiently gummed up to seal with grease 3) have one you added gaskets to.
So a heat sink/water pan becomes a crutch to compensate for the increased airflow you don't want. I'm not convinced the added moisture keeps food juicy. That's called "steam" and it goes out the top.
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I don't use water anymore, because my results didn't improve when I did. And it's a messy sludge you don't want to toss in the yard or down the sink. SO, my "water pan" is only functioning as a diffuser and drip pan, covered in foil for easier cleanup.