Why is my pizza coming out "soggy"?

First of all, like Max said you should definitely be cooking your pizzas at a higher temperature. In any case, this doesn't sound like an oven problem. If the more toppings you put then the more watery your pizzas get, it would only makes sense that your toppings are releasing water. Even if you strain canned mushrooms they will still retain a lot of water. Some cheeses have a lot of water in them, but this mostly happens with fresh mozzarellas. In general I'd say experiment by cooking pizzas with only one topping to see which are releasing water, then make the necessary adjustments.

IMO, 475 is not enough, turn up the heat to as high you can get it, 600+ if possible.

You want to bake the pizza as quick as possible.

Use fresh ingredients, especially mushrooms, they tend to absorb a lot of water if canned (and hard to remove).

Check the tomato sauce, maybe you put too much on your pizza.

Make sure you give your sauce a quick stir before use. If it's a heavy topping pizza use your judgement and compensate with less sauce and cheese. Also check air flow of the oven. Regulating the cook time for top of the pizza may help evaporate the moisture. Experiment first it's easy to cook the top too fast

I got to study abroad in Italy this past summer. We dropped by a pizzeria and talked to the owner on how he makes his pizza the way he does. Here was his advice:

• Make sure you knead the dough thoroughly, adding more flour as you go (especially under the center).
• The only ingredients that should have a saucy component (or additional water) would be your marinara. Here in the states, I would suggest adding tomato paste or just a can of tomato paste to can of diced tomatoes.
• Ingredients are going to increase the cooking time, especially in the center; but this doesn't matter.
• The man used a brick oven with logs (so no regulation of temperature). He said that "You know when to put it in by the color of the brick." This deep dark red is usually at 600-650 and is only meant for 5 minutes. "From start to finish, a pizza should only take 15 minutes to get to the table."
• Lastly, he mentioned you know the pizza is done by two factors.
  • The sides of the pizza are a dark golden brown.
  • The bottom of the pizza is charred at sporadic locations.
• Note: True Italian style pizzas actually come out more soggy than their American counterparts and should be eaten with a fork and knife.

  ---

  To answer your question, look to my second bullet point. My family has always mays a thicker sauce that we spread very thinly. The tomato paste will help cut down on the runniness of your current sauce.