I'll come clean. I've been emotionally involved with my pressure cooker for many years now. It's always there when I need it, very fast and it produces tasty meals. What more could any person want?
There is more. It can also be a very energy efficient choice for your cooking.
In the last month I've used it to save energy cooking: Roast chicken, lamb curry, beef & vegetable pie, chicken & pearl barley soup but you can use pressure cookers very effectively with pulse based vegetarian meals as well.
In the first three meals, I used the pressure cooker to pre-cook the ingredients prior to adding them to the rest of the meal. The soup was cooked entirely using the pressure cooker.
Here's how my calculations work out on energy saving.
On my propane range (we live in rural Wales) I simmer on the lowest setting on the smallest ring which is rated at 0.3KW. I use a 3.5kW ring to bring the cooker to pressure. These ratings mean that each ring uses that amount of energy in a hour.
This means, that once the pans are up to heat* the pressure cooker consumes energy about five times as fast as simmering. Therefore, any cooking that takes more than five times as long as cooking 'normally' will use more energy. With the more flavourful meats that require long slow cooking, the pressure cooker is a real bonus.
For the roast chicken the calculation is a little more involved. A 1.5kg chicken will need about 20-25 minutes pre-cooking in the pressure cooker depending on whether you want it firm or falling apart! This uses about 1kW. In my small oven the elements combined are 1.5kW. After the pre-cook you can brown the chicken in the oven for 10-15 minutes using 0.4 kW. Including bringing the cooker up to pressure*, this method uses less than 2kW in total.
Using just the oven, the minimum roasting time (from warm oven) is from about 80 minutes to give just cooked, to 120 minutes for falling apart. So the energy usage would range from about 2kW to 3kW.
If I use my big oven I can cook other things such as roast potatoes as well. So this will affect the usage and saving. If you're not roasting other things there's no need to brown and you have a beautifully tender, moist chicken. And, either way, you get some 'free' stock for your gravy at the same time.
Being frugal, I reused the chicken carcass with more veg to make stock for the soup. This took 20 minutes pressure cooking. Jamie Oliver recommends 3-4 hours simmering for chicken stock. So pressure cooking uses 50% of the energy of the slow simmer method.
To make the soup, I strained out the stock, fried some veggies in the pressure cooker, added the pearl barley & popped the stock back in with some seasoning. 20 minutes pressure cooking later, I had a beautiful tasty soup ready to serve with a herb garnish.
I cooked the lamb for the curry (stewing cuts, neck etc) in 10 minutes from coming to pressure. It would have taken about 90 minutes or so to do that normally - almost a 50% saving. While that cooked I made the curry sauce and added the lamb & some cooking stock to that to combine flavours
With the beef I was under time pressure to get a meal ready super quick. The (welsh black) stewing beef was frozen. I didn't have the time to thaw it & then to gently simmer it for 2 to 3 hours. It cooked to super tender in the pressure cooker in 20 minutes from frozen. I then added the cooked beef and some of the thickened cooking stock to the vegetables for the pie mix.
Pressure cooking is not suitable for everything. I think vegetables by themselves and fish deserve quick cooking to preserve texture and flavour.
Some flavourings such as gentle herbs and many spices do not survive the pressure process and you need to think of other ways to incorporate these flavours afterwards. For example, the roast chicken had lemon slices under the breast skin for flavour and these survive the process. However, if I'd used say thyme and garlic to flavour these would not. The solution is to mix up some olive oil with the herbs & garlic and paint this on the chicken prior to the final browning in the oven.
Meats that are very lean don't really benefit texture-wise from the method.
So pressure cooking is not a solution for every meal. It is a useful contribution with the right ingredients for super succulent food cooked fast using less energy. And, if you're clever, you can do it all in the one pan and so save on your washing up too.
You could love your pressure cooker too...
*I've assumed that getting to cooking temperature takes about the same amount of energy for both methods. There is a difference but it's not material. It takes about 5 minutes using the 3.5kW ring to get the pressure cooker up to pressure using about 0.3kW.
Carl Legge is the author of The Permaculture Kitchen, a book of seasonal, local, home-grown delicious recipes for Permanent Publications, the book publishing arm of Permaculture magazine. He lives on the Llyn Peninsula in Wales on a permaculture smallholding and writes a regular blog full of delicious recipes and more.