Chances are that if you are beginning to take an interest in your food, you may also lean toward home prepared versus industrially prepared foods.
As more food preparation takes place in the home, and less in the factory, the energy bill of the factory decreases, but that of the home increases. More of the energy used in the food chain falls under the control of the local chef. This presents both an opportunity and responsibility to apply a little critical thinking to the energy consumed in the kitchen.
Energy intensive home cooking tasks include: cooking beans, rendering down broths. Sustainable energy sources certainly become easier to consider. Cooking vegetables is less intensive.
Boiling vegetables is the default cooking method in many kitchens, but how does boiling compare to steaming? The following is more intuition than science.
Firstly, steaming vegetables uses less water. Secondly, bringing less water to a boil uses less energy. Thirdly, less water requires less energy to maintain a boil. Steaming appears to be more energy efficient that boiling.