Considering the prices of Le Creuset and other high quality enamel on cast iron cookware, figuring out what size dutch oven to purchase is an important question. If you purchase a piece that is too large, it is going to cost you extra money. Also, enamel coated cast iron pans are heavy, so a too large pan means extra effort when you use it.
On the other hand, purchasing one too small means cramming your food in the pot, allowing it to steam rather than braise or roast. This makes your food mushy and renders your investment in good quality cookware nearly worthless.
The way manufacturers measure dutch ovens (also called French Ovens) is confusing. Sometimes it is the radius of the cookware - but is the measurement in centimeters or inches? Sometimes it's how much volume the pot will hold. But how do those measurements convert to what we really need to know: What is the best dutch oven size to produce a certain number of servings.
As a rough rule, I use the following guide:
Cooking for 1-3 people? Use a 4.5 or 5.5 quart dutch oven. Cooking for 4-8 people? Move up to the 7.5 quart, and seriously consider purchasing the 9 quarter. Cooking for party of 10 or more? The 13.5 monster is what you need, but be sure you will have help or lots of muscles to move it from stove top to oven, or from oven to table.
The cast iron does produce the terrific even heating the Le Creuset Dutch Oven is famous for; however, it also makes the cookware quite heavy. One of these 13.5 quart bad boys will make some grandfathers worry about a hernia. On the plus side, nothing is better for braising or for slow cooking for a crowd.
You should also consider the shape of your dutch oven. Many sizes come in a choice of oval or round. The more traditional round shape fits well on a stove top burner. When used on the stove top, the oval shape does produce a bit of uneven heating around the far edges that are outside the heating ring. However, that is not a big deal when you use Le Creuset primarily for slow-cooking in the oven. In the larger sized french ovens, the oval shape is a minor inconvenience compared to the big benefit of being able to easily fit a whole chicken or a roast into the pot.
Think about what the best dutch oven size for your needs is prior to purchasing and you will receive big returns on your investment in Le Creuset.
