PASSIVE COOKING USING A BLANKET: IT CAN’T BE MORE SUSTAINABLE THAN THIS
Today I want to share with you a photo of this chickpea salad bowl, a simple but very tasty dish. What’s so special about it? Nothing, except the fact that the chickpeas are prepared by passive cooking, using a blanket.
Legumes are cornerstones of sustainable cooking, but also of any other well-balanced mealplans. Reducing animal proteins should make us increase their consumption, so as to cover the requirements for proteins and minerals. Fortunately, legumes are very versatile and can be used in dozens of variations for each phase of a meal: appetizers, soups, pastas, side dishes, main courses, but also as… desserts!
Every rose has its thorn and legumes make no exception; cooking them so as not to risk a bad digestion, involves a considerable expenditure in terms of energy and greenhouse gas emissions. And we should also know that 80% of energy applied in our kitchens are dedicated for cooking. Is there anything we can do to mitigate the situation? Sure we can, following my instructions for this simple but effective passive cooking method using a blanket, we can make a difference: reducing our carbon footprint and energy costs considerably, without compromising on health.
For years I have been successfully passive cooking pasta with the stove turned off (with the term “successful”, I mean by my standards: I would never call myself a gourmet, instead I prefer to vaunt of my practicality in the kitchen); but I had never considered extending this method for legumes. Until one day, my gas tank let me down out of the blue: we were sailing over a rough sea and replacing it was just unthinkable, so I remembered this ancient solution and started to apply it with a certain skepticism; on the other hand there was nothing to lose, except our lunch -thought to be pasta and chickpeas. Well, skepticism apart, I can confirm it out loud: you can do it!
In fact, it’s so easy to give way to doubt about its goodness!
What you need besides a stove and a pressure cooker, is just a large blanket made of wool or heavy fleece and of course plenty of time. Recently ‘slow cookers’, alias ‘crock-pot’ that offer this type of slow cooking are very popular: everyone says that you should try those “portentous” pots, with cooking times ranging from 8 to 12 hours, and significant purchase costs if you require the quality. But I can’t spend so much on a device that I can rarely use (you know I’m a “nomad”, who lives most of the year aboard on a sail boat and for me, using 220 Volts for such a long time is not always easy). And so my “genius stunt” which has peasant roots, has nothing to envy to those elegant pots: the farmers who were leaving home early in the morning to go to work in the fields, were bringing with them the pots full of foodstuff, of which cooking stage was slowly completed under heavy blankets while they were working.
I’d strongly recommend you to use the pressure cooker; I know that there are many of you who have doubts about its safety, but I have to add unjustly: it is both very safe and indispensable to save time, energy and greenhouse gases. If you use it properly; which doesn’t mean anything mysterious or complicated, just don’t forget to clean its valves and seals well, and don’t exceed the indicated capacity level of the pot; modern pressure cookers equipped with safety valve and recognized brands are to be considered really safe. The initial investment may perhaps frighten you, but I assure you that already in a year you can amortize the cost difference from a normal one, thanks to the gas or electricity savings.
Let’s start from the beginning: Soak 500 grams of chickpeas for 36 hours, changing the water every 6-8 hours to reduce the phytate content, but as well other anti-nutrients such as protease inhibitors, lectins, tannins and calcium oxalates. When this time limit expires, rinse them off for the last time and put the chickpeas in your pressure cooker with plenty of cold water to cover them.
When the pressure cooker arrives at operating pressure, it starts whistling or the red button is popped up; at this point lower the heat, note down the time, and continue to cook: 7 minutes is more than enough to have an impeccable cooking for chickpeas, without running any risk of intoxication or food infection. Once the stove is turned off, use a thick table mat to insulate the base of the pot well, and wrap everything with one or two heavy blankets: carefully place the ‘bundle’ in an area at room temperature, sheltered from the wind.
One day I measured the temperature of the pot (just for my curiosity, and not for scientific purposes since I do not have a reliable tool): at a pressure of 1 bar we can cook ‘nominally’ at 121 degrees; but we are talking about nominal values, i.e. factory values and not taking reality into account. This means that even if the pressure was below 1 bar we would still reach a temperature of about 110 degrees: in any case, a very respectable temperature for food hygiene. Starting from this theoretical data I made my measurements: after 1 hour the external temperature of the pot was still above 60 degrees (although I don’t know how much above: my thermometer has 60°C as full scale); after 4 hours it had dropped to 55 degrees; after 8 hours to 35 degrees. And hear hear, after that time the chickpeas are perfectly cooked!
Of course for some folks it may not seem very brilliant to spend so much time on such a simple dish. But I start from an equally disarming reasoning which starts from the old proverb “in for a penny in for a pound”: if I preferred dedicating 36 hours for the soaking phase to obtain a healthier and more nutritional food, what would be another 8 hours for cooking?! On the other hand, these extra 8 hours will pass without any effort, skill or presence of a person: even your supervision is not required. You just need to organize yourself and remember when you come back from work, while preparing the dinner of the day, to prepare also the dinner of the day after tomorrow. By now, the following is my infallible method: for example, on Tuesday evening I soak the chickpeas, on Thursday morning I cook them with the passive cooking method, in the evening when I turn back home, I mix them with the other ingredients as I like and serve them whether hot or not. Nothing is easier, and if we consider that with the normal procedure of pressure cooking, the required time is about 30 minutes, (while with a traditional pot it may take even 90 minutes) I‘d saved about 23 minutes of gas (or 83 in the other case). It means that I can cook with this method other 3 more times for free and without producing greenhouse gases; or more in the case of lentils, which require only 5 minutes of cooking, after the red button pops up. Don’t you think this is a great idea?
But wait, there’s more!
If you had not yet convinced yourself to dedicate so many precious hours to the poor legumes, wait for the rest.
The aspired iron contained in legumes is not assimilated simply by swallowing them. Unfortunately, its bio availability is adversely affected by the presence of anti-nutrients such as phytates. The only way to reduce their concentration is to soak them for many hours and in the meantime, to make many rinses; otherwise the phytates will always be too many and the bio availability of iron will be less and less(*).
But now I want to explain to you what happens with long cooking times.
You know what else bothers the phytates? The high temperature. Well, so using the pressure cooker to cook legumes would seem very wise to obtain a greater destruction of phytate, considering that cooking in the pressure cooker takes place at 121 degrees; however, prolonged cooking at high temperatures would threaten to damage most minerals, including iron. At this point I imagine you have already guessed how to obtain more iron from some legumes: the passive cooking method with the blanket, allows to applicate high temperatures only for a short period, and this gives us a valid compromise to have as less phytate as possible and as much iron as possible.
Food not suitable for this method
Slow cookers when set to Low, they work around 85°C; the passive cooking technique with the blanket, however cannot maintain a temperature above 63 degrees for several hours (in the food hygiene jargon the temperature between 5 and 63 degrees is defined ‘danger zone’, in particular between 20 and 50 degrees). This does not allow an acceptable guarantee to stop the proliferation of pathogenic bacteria or spores. For this reason, do not use it for cooking food that may pose a health risk: such as meat in general (red, white, seafood or fish), rice (due to the risk from Bacillus cereus), nor potatoes when not washing their skins (Clostridium botulinum); nor red kidney beans or black eyed beans (Clostridium perfringens). Therefore, in order not to create any hazard to health, I would advise you to use standard methods for these foods.
In addition, phytohaemagglutinin, a lectin that acts as a natural toxin in plants to defend themselves against parasite attacks etc., present in fresh and dried beans (in particular red kidney and white beans) needs to be heat-treated appropriately in order to be degraded and thus become harmless; for this reason use the standard cooking method also for these species of beans. Regardless of the method chosen, always wash them very well before cooking
Enjoy your meal and good revolution to all
(*) R.Y. Khattab, S.D. Arntfield. (2009). Nutritional quality of legume seeds as affected by some physical treatments LWT – Food Science and Technology ISSN: 0023-6438, Vol: 42, Issue: 6, Page: 1113-1118.