Green bean casserole usually bakes for about 30–40 minutes in a 350°F (175°C) oven until it is hot, bubbly, and the topping is golden brown.

Typical bake time

• For a standard recipe using canned or frozen green beans and cream soup, bake uncovered at 350°F for about 30 minutes, then check that the center is hot and the edges are bubbling.

• Many traditional versions that also brown a fried onion topping run closer to 35–40 minutes total at 350°F.

If made ahead or from scratch

• If the assembled casserole has been refrigerated, add about 10 minutes of baking time to ensure it heats through before the top browns.

• Scratch versions with a from‑scratch sauce sometimes use a hotter oven (400–425°F) but then only need about 15–25 minutes, again baking until bubbly and golden.

Quick doneness check

• The casserole is done when the sauce is visibly bubbling in the center, the green beans are tender, and the topping is lightly browned and crisp.