1 00:00:01,840 --> 00:00:08,760 Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff, Lauren Bolebaum. Here, 2 00:00:10,640 --> 00:00:14,760 Speaker 1: Burned chunks or gooey paste can be the disappointing result 3 00:00:14,920 --> 00:00:18,160 Speaker 1: of rice gone wrong, but with the use of a 4 00:00:18,239 --> 00:00:21,440 Speaker 1: rice cooker, the odds even up for even the glutsiest 5 00:00:21,520 --> 00:00:25,400 Speaker 1: in the kitchen. A rice is the staple grain in 6 00:00:25,440 --> 00:00:28,720 Speaker 1: many cuisines around the world. But before the invention and 7 00:00:28,800 --> 00:00:33,440 Speaker 1: adoption of modern kitchen technology alike electric and gas heating elements, 8 00:00:33,840 --> 00:00:38,080 Speaker 1: cooking rice was a finicky, hours long process that required 9 00:00:38,120 --> 00:00:41,520 Speaker 1: you to stand around over a cast iron pot, making 10 00:00:41,520 --> 00:00:44,440 Speaker 1: adjustments to a coal or wood fire in order to 11 00:00:44,440 --> 00:00:46,839 Speaker 1: get the heat just right during different parts of the 12 00:00:46,880 --> 00:00:51,559 Speaker 1: cooking process. Although simple electric rice cookers go back to 13 00:00:51,600 --> 00:00:55,160 Speaker 1: the nineteen twenties in Japan, the first commercial one for 14 00:00:55,240 --> 00:01:00,520 Speaker 1: home use didn't debut until nineteen fifty six from Tashiba. People, 15 00:01:00,720 --> 00:01:03,680 Speaker 1: and perhaps specifically women who often took on the task 16 00:01:03,920 --> 00:01:07,839 Speaker 1: were Ready. Company records show that just four years later, 17 00:01:08,120 --> 00:01:12,600 Speaker 1: about half of Japanese homes had a rice cooker. These days, 18 00:01:12,760 --> 00:01:15,760 Speaker 1: rice cookers range from basic models that'll run you less 19 00:01:15,800 --> 00:01:18,839 Speaker 1: than thirty bucks to ones with fancy features that cost 20 00:01:18,880 --> 00:01:22,680 Speaker 1: over five hundred and Although they're ostensibly meant for cooking 21 00:01:22,800 --> 00:01:27,680 Speaker 1: you know, rice, they can be very versatile. Some people 22 00:01:27,800 --> 00:01:31,080 Speaker 1: use rice cookers as their primary cooking tool for everything 23 00:01:31,160 --> 00:01:36,200 Speaker 1: from spaghetti to spare ribs to scrambled eggs. So today 24 00:01:36,440 --> 00:01:41,880 Speaker 1: let's talk about the technologies behind rice cookers. Rice needs 25 00:01:41,920 --> 00:01:45,080 Speaker 1: two things to go from hard, shelf stable grains to 26 00:01:45,319 --> 00:01:50,240 Speaker 1: tender morsels, lots of water and lots of heat. You 27 00:01:50,480 --> 00:01:53,760 Speaker 1: generally accomplish this by boiling grains of dried rice in 28 00:01:53,880 --> 00:01:57,080 Speaker 1: water anywhere from equal parts of each to twice as 29 00:01:57,160 --> 00:02:01,080 Speaker 1: much water by volume. The rice is done when all 30 00:02:01,120 --> 00:02:03,760 Speaker 1: of the water has been absorbed and or steamed off, 31 00:02:04,080 --> 00:02:07,120 Speaker 1: and the grains are whatever degree of tender you're looking for. 32 00:02:08,440 --> 00:02:11,360 Speaker 1: It is ideal if you can do this without melting 33 00:02:11,400 --> 00:02:14,000 Speaker 1: a layer of rice into a sticky, burnt mass at 34 00:02:14,000 --> 00:02:17,160 Speaker 1: the bottom of the pot. There are a few ways 35 00:02:17,160 --> 00:02:21,320 Speaker 1: to accomplish this automatically. Most start with an electric heating 36 00:02:21,320 --> 00:02:23,840 Speaker 1: element set into a base which can also hold a 37 00:02:23,840 --> 00:02:27,200 Speaker 1: cooking pot. You add rice and water and cover with 38 00:02:27,200 --> 00:02:29,840 Speaker 1: the lid that came with the appliance. The heating element 39 00:02:29,880 --> 00:02:34,120 Speaker 1: heats the pot, which boils the water. But how does 40 00:02:34,160 --> 00:02:39,200 Speaker 1: it know when it's done. The classic technology, the least expensive. 41 00:02:39,400 --> 00:02:42,959 Speaker 1: The type I've got operates on a simple heat sensitive 42 00:02:43,200 --> 00:02:47,720 Speaker 1: magnetized switch. Okay, you turn on this type of rice 43 00:02:47,720 --> 00:02:50,000 Speaker 1: cooker by pressing down a switch on the outside of 44 00:02:50,000 --> 00:02:53,240 Speaker 1: the unit, and when you do, you'll hear a little clock. 45 00:02:53,639 --> 00:02:56,240 Speaker 1: That's because the switch is connected to a lever that 46 00:02:56,320 --> 00:02:59,240 Speaker 1: brings two surfaces in contact with each other that are 47 00:02:59,320 --> 00:03:03,920 Speaker 1: electrically conducive. This completes an electrical circuit and powers the 48 00:03:03,960 --> 00:03:07,600 Speaker 1: heating element. The circuit stays closed because the two surfaces 49 00:03:07,639 --> 00:03:12,760 Speaker 1: are magnetic, but one surface, the upper surface of the pair, 50 00:03:13,320 --> 00:03:16,000 Speaker 1: is made of a material that's only magnetic up to 51 00:03:16,040 --> 00:03:19,240 Speaker 1: about one hundred and two degrees celsius, which is right 52 00:03:19,280 --> 00:03:23,119 Speaker 1: above the boiling point of water. This is a very 53 00:03:23,280 --> 00:03:27,440 Speaker 1: clever bit of physics. Water boils at one hundred degrees 54 00:03:27,480 --> 00:03:31,440 Speaker 1: celsius and won't get hotter than that at normal Earth pressure. 55 00:03:32,320 --> 00:03:34,800 Speaker 1: So as long as there's water in the pot as 56 00:03:34,840 --> 00:03:37,400 Speaker 1: the rice is cooking, the temperature at the bottom of 57 00:03:37,480 --> 00:03:41,160 Speaker 1: the pot will hold steady. At one hundred the temperature 58 00:03:41,200 --> 00:03:44,680 Speaker 1: is in check thanks to the presence of water, but 59 00:03:44,840 --> 00:03:47,680 Speaker 1: when it's all absorbed and or boiled off, the heating 60 00:03:47,720 --> 00:03:49,960 Speaker 1: element can get to work on the pot and or 61 00:03:49,960 --> 00:03:53,320 Speaker 1: the rice itself, which can get considerably hotter than one 62 00:03:53,360 --> 00:03:57,680 Speaker 1: hundred degrees at normal Earth pressure, so the temperature at 63 00:03:57,680 --> 00:04:01,600 Speaker 1: the bottom of the pan leaps up, at which point 64 00:04:01,880 --> 00:04:05,840 Speaker 1: our temperature sensitive magnet stops being magnetic and drops the 65 00:04:05,880 --> 00:04:08,960 Speaker 1: other half of the pair, breaking the circuit and turning 66 00:04:08,960 --> 00:04:14,000 Speaker 1: the heating element off with another little clunk. Except in 67 00:04:14,040 --> 00:04:16,320 Speaker 1: a lot of rice cookers like this, the heating element 68 00:04:16,360 --> 00:04:19,000 Speaker 1: doesn't turn all the way off, but rather switches to 69 00:04:19,080 --> 00:04:23,400 Speaker 1: a warming function. This works thanks to another type of 70 00:04:23,400 --> 00:04:28,080 Speaker 1: heat sensitive switch called a bimetal switch. A bimetal switch 71 00:04:28,120 --> 00:04:29,800 Speaker 1: is a type of switch that's made up of two 72 00:04:29,800 --> 00:04:34,480 Speaker 1: types of metals sandwiched together. Makes sense, right. Each of 73 00:04:34,520 --> 00:04:37,479 Speaker 1: the two is chosen because they are bendable and because 74 00:04:37,520 --> 00:04:41,520 Speaker 1: they expand at different rates when exposed to heat. So 75 00:04:41,640 --> 00:04:44,560 Speaker 1: the switch starts out flat but will bend one way 76 00:04:44,680 --> 00:04:47,640 Speaker 1: or the other at different temperatures because the metals are 77 00:04:47,640 --> 00:04:52,440 Speaker 1: expanding or shrinking at different rates, and you can use 78 00:04:52,480 --> 00:04:56,440 Speaker 1: this property to connect and disconnect a circuit at different temperatures. 79 00:04:57,400 --> 00:04:59,560 Speaker 1: In the case of our rice cooker, at around sixty 80 00:04:59,560 --> 00:05:03,279 Speaker 1: degrees ce elius, that's one forty fahrenheit fairly cool. The 81 00:05:03,279 --> 00:05:06,400 Speaker 1: switch bends and connects the circuit, turning the heating element 82 00:05:06,440 --> 00:05:10,440 Speaker 1: on a butt at around eighty celsius or one hundred 83 00:05:10,480 --> 00:05:13,960 Speaker 1: and seventy five fahrenheit fairly hot. The switch bends the 84 00:05:14,000 --> 00:05:17,400 Speaker 1: other way, breaking the circuit and turning the element off. 85 00:05:18,640 --> 00:05:21,360 Speaker 1: It will keep toggling, holding the temperature of the pot 86 00:05:21,480 --> 00:05:26,400 Speaker 1: nice and warm until you unplug the unit. But of 87 00:05:26,480 --> 00:05:31,200 Speaker 1: course we humans are not confined to manual physical switches anymore. 88 00:05:32,160 --> 00:05:35,920 Speaker 1: Digital rice cookers contain digital thermometers connected to a simple 89 00:05:35,920 --> 00:05:38,120 Speaker 1: computer that can be programmed at the touch of a 90 00:05:38,120 --> 00:05:40,760 Speaker 1: few buttons on the outside of the unit to heat 91 00:05:40,920 --> 00:05:43,960 Speaker 1: or warm the pot, two particular temperature settings, four particular 92 00:05:44,040 --> 00:05:47,720 Speaker 1: lengths of time, like the way that we use standard microwaves. 93 00:05:48,920 --> 00:05:53,440 Speaker 1: Computer controlled rice cookers were first introduced in nineteen seventy nine. 94 00:05:53,720 --> 00:05:55,840 Speaker 1: But if you are going to go ahead and put 95 00:05:55,880 --> 00:05:58,839 Speaker 1: a computer into a rice cooker, why not ask it 96 00:05:58,920 --> 00:06:02,159 Speaker 1: to do a bit more work for you. Rice cookers 97 00:06:02,200 --> 00:06:04,720 Speaker 1: were one of the first home appliances to make use 98 00:06:04,760 --> 00:06:07,600 Speaker 1: of the theory of fuzzy logic, which was developed by 99 00:06:07,640 --> 00:06:11,239 Speaker 1: computer scientists in the nineteen seventies and now helps everything 100 00:06:11,279 --> 00:06:16,600 Speaker 1: from washing machines to refrigerators to subway cars function. Fuzzy 101 00:06:16,640 --> 00:06:21,480 Speaker 1: logic is sort of what it sounds like, logic with variables. 102 00:06:22,680 --> 00:06:26,320 Speaker 1: Digital devices operate on boolean logic, which means ones in 103 00:06:26,440 --> 00:06:31,000 Speaker 1: zeros you know on or off, yes or no. Fuzzy 104 00:06:31,040 --> 00:06:33,680 Speaker 1: logic opens up the field of answers to all of 105 00:06:33,720 --> 00:06:38,120 Speaker 1: the numbers in between one and zero. Devices programmed with 106 00:06:38,200 --> 00:06:42,400 Speaker 1: it can recognize an almost yes versus a slightly yes 107 00:06:42,720 --> 00:06:47,160 Speaker 1: and act accordingly. This lets you program algorithms that take 108 00:06:47,279 --> 00:06:52,080 Speaker 1: variables into consideration, like not just is the pot hot, 109 00:06:52,360 --> 00:06:55,760 Speaker 1: but is it getting hotter quickly, and then make a 110 00:06:55,800 --> 00:06:58,440 Speaker 1: decision about how to control the temperature based on that. 111 00:06:59,760 --> 00:07:02,640 Speaker 1: Idea is that these machines can adjust for the actual 112 00:07:02,680 --> 00:07:07,400 Speaker 1: circumstances occurring in real time. Maybe the ambient pressure is 113 00:07:07,440 --> 00:07:11,080 Speaker 1: making the cooking go faster, or you added too much water, 114 00:07:11,480 --> 00:07:15,800 Speaker 1: and it can cook the rice perfectly regardless. It's way 115 00:07:15,840 --> 00:07:19,600 Speaker 1: better than just using on off temperature settings, and probably 116 00:07:19,640 --> 00:07:23,080 Speaker 1: better than any adjustments a hungry and impatient human might make. 117 00:07:24,360 --> 00:07:27,280 Speaker 1: While fuzzy logic rice cookers function under the same premise 118 00:07:27,360 --> 00:07:31,280 Speaker 1: as basic models, their mathematical programming can deliver a slew 119 00:07:31,360 --> 00:07:35,920 Speaker 1: of customized cooking options, making precise fluctuations in cooking time 120 00:07:35,960 --> 00:07:40,840 Speaker 1: and temperature depending on the programs selected. These may include 121 00:07:40,840 --> 00:07:45,600 Speaker 1: settings for white rice of varying textures, sushi rice, jasmine rice, 122 00:07:45,760 --> 00:07:50,640 Speaker 1: brown rice, germinated brown rice, mixed rices, knge steel cutoats, 123 00:07:50,840 --> 00:07:55,600 Speaker 1: rapid cooking, extended warming, and reheating. And that's just the beginning. 124 00:07:56,440 --> 00:08:00,840 Speaker 1: Some machines have settings for steaming foods, baking cakes, auto cleaning, 125 00:08:01,240 --> 00:08:03,920 Speaker 1: and delayed timers, so you can preset the machine to 126 00:08:03,920 --> 00:08:08,000 Speaker 1: start cooking at a particular time. Oh and if you 127 00:08:08,160 --> 00:08:11,040 Speaker 1: do want a layer of crisp, golden brown rice at 128 00:08:11,040 --> 00:08:14,120 Speaker 1: the bottom of your pot for dishes like tadig, there 129 00:08:14,160 --> 00:08:17,000 Speaker 1: are rice cookers for that too. You add a bit 130 00:08:17,000 --> 00:08:19,360 Speaker 1: of vegetable oil to the pot, and after the main 131 00:08:19,360 --> 00:08:21,800 Speaker 1: cooking is done, a timer holds the pot to the 132 00:08:21,840 --> 00:08:26,080 Speaker 1: heat long enough to crispit. There are also rice cookers 133 00:08:26,120 --> 00:08:29,200 Speaker 1: out there that don't use a standard electric heating element. 134 00:08:30,040 --> 00:08:33,439 Speaker 1: These days, you can find models that use induction heating technology, 135 00:08:33,920 --> 00:08:36,360 Speaker 1: which I could have sworn had already done an episode about, 136 00:08:36,400 --> 00:08:38,360 Speaker 1: but I have not, and I'll have to rectify that 137 00:08:38,440 --> 00:08:43,360 Speaker 1: in the future. Very basically, induction cookers don't waste energy 138 00:08:43,400 --> 00:08:46,240 Speaker 1: heating an element that then heats a pan, but rather 139 00:08:46,400 --> 00:08:50,439 Speaker 1: use magnetic fields to heat the pan directly. There are 140 00:08:50,480 --> 00:08:54,199 Speaker 1: also pressure rice cookers, which seal and pressurize their contents 141 00:08:54,280 --> 00:08:58,080 Speaker 1: to allow for faster cooking times and hotter temperatures. Pressure 142 00:08:58,080 --> 00:09:02,080 Speaker 1: cooking also a whole different episode. Whatever kind of rice 143 00:09:02,080 --> 00:09:04,920 Speaker 1: cooker you're using, there are all kinds of recipes out 144 00:09:04,960 --> 00:09:06,679 Speaker 1: there for how to get the most out of it. 145 00:09:06,840 --> 00:09:10,600 Speaker 1: When it comes to rice and beyond, at a certain point, 146 00:09:10,679 --> 00:09:13,320 Speaker 1: it's a hot pad with a fitted pot. Anything you 147 00:09:13,400 --> 00:09:16,160 Speaker 1: want to warm or cook, especially anything involving a lot 148 00:09:16,160 --> 00:09:18,920 Speaker 1: of liquid, can be done in a rice cooker with 149 00:09:19,200 --> 00:09:23,440 Speaker 1: enough tenacity a rice cooker. Poached fruit, hard boiled eggs, 150 00:09:23,679 --> 00:09:27,800 Speaker 1: homemade soups, whatever you're cooking in it. Take a moment 151 00:09:27,840 --> 00:09:31,280 Speaker 1: to appreciate your humble or not so humble rice cooker, 152 00:09:31,920 --> 00:09:34,320 Speaker 1: and if you don't have one, consider picking up a 153 00:09:34,320 --> 00:09:38,320 Speaker 1: basic model. After all, it's a robot that, if it 154 00:09:38,400 --> 00:09:41,640 Speaker 1: could want things, would want you to eat good rice. 155 00:09:42,480 --> 00:09:49,719 Speaker 1: That's a good robot to have around. Today's episode is 156 00:09:49,760 --> 00:09:52,600 Speaker 1: based on the article how rice cookers work on HowStuffWorks 157 00:09:52,600 --> 00:09:55,480 Speaker 1: dot com, written by Jessica Tooothman for more about the 158 00:09:55,559 --> 00:09:58,280 Speaker 1: history of rice cookers. Check out my other podcast Savor 159 00:09:58,640 --> 00:10:02,760 Speaker 1: for the Warm and Fuzzy rice Cooker episode. Brainstuff is 160 00:10:02,760 --> 00:10:05,319 Speaker 1: production by Heart Radio in partnership with how stuffworks dot 161 00:10:05,320 --> 00:10:08,000 Speaker 1: com and is produced by Tyler Klang. But four more 162 00:10:08,040 --> 00:10:12,120 Speaker 1: podcasts from iHeartRadio. Visit the iHeartRadio app, Apple Podcasts, or 163 00:10:12,160 --> 00:10:14,000 Speaker 1: wherever you listen to your favorite shows.