{"id":1175,"date":"2018-04-10T16:04:22","date_gmt":"2018-04-10T20:04:22","guid":{"rendered":"http:\/\/harvestpartners.farm\/connect\/?p=1175"},"modified":"2018-04-10T19:02:25","modified_gmt":"2018-04-10T23:02:25","slug":"what-is-pressure-cooking-doing-to-your-food","status":"publish","type":"post","link":"https:\/\/harvestpartners.farm\/connect\/2018\/04\/10\/what-is-pressure-cooking-doing-to-your-food\/","title":{"rendered":"What is Pressure Cooking Doing to Your Food?"},"content":{"rendered":"

Cooking Methods Matter<\/h3>\n

How food is grown\u00a0greatly affects its flavor and nutrition.\u00a0 But cooking and preparation methods also play a big role in the availability of nutrients and the presence of toxins and anti-nutrients.\u00a0 Why spend good money or effort\u00a0finding high-quality food (such as grass-fed beef and lamb, pasture-raised chicken and eggs and organic vegetables), only to lose the benefits during preparation?<\/p>\n

The Modern Programmable Cooker<\/h3>\n

We live out of our freezer for our meat and eat a wide variety of fresh and frozen vegetables.\u00a0 So, we’ve really enjoyed the convenience of our Instant Pot programmable cooker.\u00a0 \u00a0But the Instant Pot, while useful as a slow cooker, saut\u00e9 pan and yogurt maker, is primarily used as a pressure cooker in our household.\u00a0 What, pray tell, is the effect of pressure cooking on your food?<\/p>\n

Does Pressure Cooking Use Really High Heat?<\/h3>\n

Conventional wisdom\u00a0once had\u00a0it that pressure cooking was a fast, high temperature method of cooking that would destroy the vitamins in your food.\u00a0 For all of us who have come to love the convenience, tenderness and vivid flavors offered by the Instant Pot, let’s hope that’s just incorrect.\u00a0 Let’s examine this more closely.<\/p>\n

Grit Your Teeth for a Return to Science Class!<\/h3>\n

You may remember from your school days (or maybe not!) the equation that relates pressure, volume and temperature:\u00a0 PV=nRT, where P=pressure, V=volume, T=temperature and, for our purposes here, nR is a numeric constant.\u00a0 This equation says\u00a0that, given a fixed volume (V) (corresponding to the\u00a0fixed size of the pressure cooker), that increasing temperature (T) will result in a proportional increase in pressure (P) or vice versa.\u00a0 Now, our pressure cookers have no way of independently increasing pressure inside the cooker (e.g.,\u00a0there are no vacuum pumps, etc.)\u00a0Therefore, pressure is strictly a function of the temperature, which in our Instant Pot, is a function of the internal heating element.\u00a0 If we leave the heating element turned on, the pressure cooker will eventually reach a maximum temperature (and pressure) limited by the size of the cooker and the heating element itself.\u00a0 The million dollar question is, “What is the maximum temperature and is it high enough to damage nutrients in the food we’re cooking?”<\/p>\n

Eureka!\u00a0 The Maximum Temperature is…<\/h3>\n

My initial research shows that we’ll need to work backwards from maximum pressure in order to find our maximum temperature.\u00a0 Fortunately, there is actually somewhat of a standard (though not a formalized one) for pressure cooker maximum pressures.\u00a0 \"\"<\/a>It’s 15 pounds per square inch (psi) for cookers made in the United States and 14.5 (psi) for European cookers.\u00a0 We\u00a0see from the chart<\/a> that the boiling point of water at\u00a015 psi is 250 degrees Fahrenheit.\u00a0 250 degrees is the maximum temperature of the steam inside the cooker and therefore, the maximum cooking temperature (assuming of course that you are suspending the food somewhere above and out of direct contact with the heating element.)\u00a0 I’m not sure where my cooker is manufactured, so I removed the pressure regulator (that little thingy that rocks back and forth on top of the older pressure cookers) and looked at the bottom of it (see picture at right.)\u00a0 It says 105 KPa which translates to just over 15 psi and corresponds to a maximum cooking temperature of about 250 degrees Fahrenheit.<\/p>\n

Does Pressure Cooking Destroy Nutrients?<\/h3>\n

The verdict?\u00a0\u00a0It turns out that most of the cooking done by the pressure cooker is a result of the pressure and the steam created inside the cooker, not the heat.\u00a0 Pressure cookers actually cook at a\u00a0lower<\/em>\u00a0temperature than most other methods (steaming, roasting, etc.) but do it more efficiently.\u00a0 It’s the combination of high pressure and steam that allows the cooker to do its job so quickly and at such (relatively) low temperature.\u00a0 So, while all cooking methods reduce nutrients to some degree, the pressure cooker is one of the better options for retaining nutrients.\u00a0 (Here<\/a> is just one study I found that showed favorable results of pressure cooking over other methods.) Now, to be fair, there\u00a0have been a few studies that showed a decrease in nutrients within the cooked foods.\u00a0 However, follow up studies showed that the nutrients were not lost but transferred to the cooking liquids within the cooker.\u00a0 It’s for this reason that we do not cover our foods with liquid in either the slow cooker or the pressure cooker but instead include a small amount of liquid in the bottom of the cooker with the food suspended on a rack above.\u00a0 You can also make a gravy, sauce or other drinkable broth from the liquid.<\/p>\n

What Can We Cook?<\/h3>\n

Today’s programmable cookers are extremely versatile and can cook anything from cheesecake to quick breads to hard-boiled eggs.\u00a0 But we use ours mostly for making stock, roasts, soups, stews and broths, vegetables and some occasional rice.\u00a0 We like that we can get a frozen\u00a0roast from the freezer to the table in about an hour and 15 or 20 minutes!\u00a0 Ground beef or Italian sausage, much faster.<\/p>\n

Pressure Cooking: Bottom Line<\/h3>\n

Like other methods of cooking, pressure cooking can destroy some of the nutrients in food, but it has been shown to preserve more than any other cooking method.<\/p>\n

With the newer programmable models, pressure cooking is a safe, convenient and healthy way to get food on the table for your family while still preserving the nutrients in your food.<\/p>\n

Do you use a pressure cooker? What’s your favorite way to use it?\u00a0 We’d love to\u00a0hear your ideas or experiences in the comments below.<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

Cooking Methods Matter How food is grown\u00a0greatly affects its flavor and nutrition.\u00a0 But cooking and preparation methods also play a big role in the availability of nutrients and the presence of toxins and anti-nutrients.\u00a0 Why spend good money or effort\u00a0finding high-quality food (such as grass-fed beef and lamb, pasture-raised chicken and eggs and organic vegetables), only to lose the benefits […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"footnotes":""},"categories":[76,110,87,28,29,30,96,35],"tags":[],"class_list":["post-1175","post","type-post","status-publish","format-standard","hentry","category-diet","category-eggs","category-food-preparation","category-grass-fed","category-grass-fed-beef","category-grass-fed-lamb","category-harmful-dietary-practices","category-pasture-raised-turkey"],"_links":{"self":[{"href":"https:\/\/harvestpartners.farm\/connect\/wp-json\/wp\/v2\/posts\/1175","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/harvestpartners.farm\/connect\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/harvestpartners.farm\/connect\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/harvestpartners.farm\/connect\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/harvestpartners.farm\/connect\/wp-json\/wp\/v2\/comments?post=1175"}],"version-history":[{"count":9,"href":"https:\/\/harvestpartners.farm\/connect\/wp-json\/wp\/v2\/posts\/1175\/revisions"}],"predecessor-version":[{"id":1187,"href":"https:\/\/harvestpartners.farm\/connect\/wp-json\/wp\/v2\/posts\/1175\/revisions\/1187"}],"wp:attachment":[{"href":"https:\/\/harvestpartners.farm\/connect\/wp-json\/wp\/v2\/media?parent=1175"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/harvestpartners.farm\/connect\/wp-json\/wp\/v2\/categories?post=1175"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/harvestpartners.farm\/connect\/wp-json\/wp\/v2\/tags?post=1175"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}