Why do crock pot recipes for roasts say to put vegetables on the bottom and roast top?

You're right, there's a good reason why most crock pot roast recipes recommend placing vegetables on the bottom and the roast on top. Here's why:

* Even Cooking: The vegetables at the bottom get exposed to more heat and moisture from the juices released by the roast as it cooks. This helps them cook evenly and prevents them from becoming dry or burnt.

* Flavor Infusion: The vegetables absorb the flavor of the roast as the juices drip down, resulting in a more flavorful and aromatic dish.

* Tenderness: The roast, being positioned above, gets bathed in the steam and juices released by the vegetables, which helps it cook evenly and become tender.

* Easy Cleanup: Having the roast on top simplifies the clean-up process as there's less mess to scrub.

However, it's not an absolute rule. Some recipes may call for a different arrangement depending on the specific ingredients and desired outcome.

Here are some variations you might encounter:

* Larger vegetables: If the vegetables are large, placing them on top allows them to cook more evenly.

* Different cooking times: Some recipes may require the vegetables to cook longer than the roast. In this case, it may be preferable to place the roast on the bottom so the vegetables don't overcook.

Ultimately, the best approach is to follow the specific instructions of your chosen recipe.