Vegetables are nature’s gift to human health. Most people don’t get enough vegetables in their diet, and even when they do, the variety is usually limited to potatoes in the form of French fries. This is unfortunate as there are countless ways to prepare vegetables – raw, mixed into salads, steamed, cooked, broiled, roasted, grilled, sautéed, and more.
Today, I’d like to share some tips about roasting.
The reason roasted vegetables taste so good is the chemical change they undergo as a result of direct dry heat in the oven. The browning effect happens at temperatures of 300-500 degrees Fahrenheit and above. This change is also called caramelization, and it is truly miraculous, morphing simple starches and sugars into complex, rich compounds with sweet, bitter, fragrant, brown-colored flavors.
These changes occur only on the outer surface of the vegetable. That is why cutting your vegetables into small pieces and increasing the total surface in contact with direct heat can intensify the flavor.
Lightly oiling your vegetables just before placing them in a pre-heated oven helps increase the surface temperature and speeds up the caramelization. To use just a tiny amount of oil, place a pound of diced veggies in a large bowl and add one tablespoon of oil, mixing well with your hands to make sure all the pieces get coated.
Make sure there is enough space in your baking pan for the veggies so that they all get a chance to caramelize. If needed, halfway through roasting you can carefully toss them about.
If the oven temperature is too high, the oil may start to smoke, creating an off taste, and releasing harmful chemicals. For olive oil, the smoke point is about 400 degrees. For other oils, such as canola, it’s slightly higher.
If you don’t have issues with salt, add a little to your roasted veggies after roasting, as the salt decreases the smoke point of the oil.
Each vegetable requires a different amount of roasting time. Here is a list of the common veggies and their roasting time at approximately 400 degrees. The time range is based on the size of each piece – smaller means less roasting time :
- Winter squash – butternut squash, acorn squash – 20 minutes to 1 hour
- Root vegetables such as beets, potatoes, sweet potato and carrots – 35 to 50 minutes
- Onions take 30 to 45 minutes
- Crucifers such as broccoli, cauliflower, Brussels sprouts – 15 to 25 minutes
- Soft vegetables like zucchini, summer squash, and bell peppers take 10 to 20 minutes.