WEBVTT - How Does Butter Get Its Texture, Flavor, and Color? 0:00:01.890 --> 0:00:07.850 Welcome to BrainStuff, a production of iHeartRadio. Hey BrainStuff, Lauren 0:00:07.870 --> 0:00:14.420 Vogelbaum here. Butter has been a source of nutrition, pleasure, disagreement, 0:00:14.640 --> 0:00:19.419 and fascination for millennia. It was probably invented by accident 0:00:19.660 --> 0:00:22.860 in many Neolithic or late Stone Age societies that were 0:00:22.920 --> 0:00:27.530 starting to herd and domesticate grazing mammals like goats, sheep, camels, 0:00:27.650 --> 0:00:32.360 and cattle around 7,000 BCE. We know that people were 0:00:32.380 --> 0:00:36.740 making butter on purpose by at least 2500 BCE because 0:00:36.780 --> 0:00:40.540 of Sumerian tablets that recorded info about the technology and 0:00:40.600 --> 0:00:44.620 ritual use of butter. It's been used in religious and 0:00:44.700 --> 0:00:49.070 spiritual practices from around Africa to India to Northern Europe 0:00:49.190 --> 0:00:53.310 and beyond, and was reviled by some olive oil-steep cultures 0:00:53.370 --> 0:00:57.630 around the Mediterranean. We've gotta admit that butter is a 0:00:57.650 --> 0:01:02.830 little magical, scientifically speaking. Today, let's talk about the science 0:01:02.970 --> 0:01:07.850 of butter. Butter is a concentration of the fatty and 0:01:07.930 --> 0:01:12.990 fat-soluble parts of milk, or cream, really. In its solid form, 0:01:13.090 --> 0:01:17.930 it's actually a crystallization of those fats. Forget gemstones, I'd 0:01:17.970 --> 0:01:20.830 like to submit butter as the most beautiful type of crystal. 0:01:22.050 --> 0:01:24.950 But in explaining butter, let's start with milk and cream. 0:01:26.390 --> 0:01:29.690 Milk is mostly water, but about 5-12% of it is 0:01:29.830 --> 0:01:33.940 little globules of fats suspended throughout that water in an emulsion. 0:01:34.980 --> 0:01:37.420 An emulsion is a mixture of two things that don't 0:01:37.500 --> 0:01:39.980 like to be mixed together, and more on how milk 0:01:40.040 --> 0:01:43.680 accomplishes that in a second. A cream is a greater 0:01:43.740 --> 0:01:51.120 concentration of those fat globules emulsified in water, about 15-25%. Butter, meanwhile, 0:01:51.220 --> 0:01:53.910 has had almost all of that water taken out. It's 0:01:53.950 --> 0:01:59.460 about 80-90% fats. Of course, there are also water-soluble and 0:01:59.560 --> 0:02:02.740 fat-soluble things mixed in with the water and fats here, 0:02:03.160 --> 0:02:07.200 proteins and sugars and minerals, but today we're mostly concerned 0:02:07.220 --> 0:02:10.870 with the fat. And now, just filtering the water out 0:02:10.910 --> 0:02:14.299 of cream won't get you butter. You have to agitate it. 0:02:15.070 --> 0:02:17.869 By agitate, I don't mean you're sending it links to 0:02:17.970 --> 0:02:22.820 inflammatory opinion pieces. You're physically shaking it up. This is 0:02:22.880 --> 0:02:25.700 necessary because in order to get the fats in there 0:02:25.800 --> 0:02:31.460 to clump together, you've got to invert the emulsion of cream. Okay, 0:02:32.000 --> 0:02:35.200 cream is, again, an emulsion, an even mixture of fats 0:02:35.240 --> 0:02:38.310 and water, which do not usually like to mix, because 0:02:38.610 --> 0:02:43.190 cream also contains these protein chains called caseins that are 0:02:43.250 --> 0:02:48.690 made up of both hydrophilic, or water-loving, and lipophilic, or fat-loving, particles. 0:02:50.080 --> 0:02:54.000 When presented with both water and fats, caseins will grab 0:02:54.080 --> 0:02:58.060 bits of fat and cluster up into globules called micelles, 0:02:58.440 --> 0:03:01.130 with the fat safely stored on the inside and the 0:03:01.370 --> 0:03:06.490 water-loving bits on the outside. These water-loving particles grab onto 0:03:06.590 --> 0:03:10.410 electrons in the water, meaning that each micelle winds up 0:03:10.450 --> 0:03:14.660 having a negative charge. And since negatively charged particles repel 0:03:14.690 --> 0:03:18.380 each other, the globules suspend themselves throughout the water in 0:03:18.419 --> 0:03:22.450 order to keep their distance. Thus, an emulsion is created. 0:03:23.130 --> 0:03:25.840 And to make butter, you have to invert that emulsion. 0:03:27.060 --> 0:03:29.360 The way you do that is you agitate it so 0:03:29.380 --> 0:03:32.900 that the micelles slam into each other, physically breaking up 0:03:32.940 --> 0:03:36.360 the bonds that hold them together. The fats that used 0:03:36.380 --> 0:03:39.630 to be cuddled safe inside the micelles are freaking out. 0:03:39.790 --> 0:03:44.170 Water is everywhere. Thrashing out for safety, they'll cling first 0:03:44.310 --> 0:03:46.890 to air bubbles in the mixture. And this is how 0:03:46.930 --> 0:03:50.210 you get whipped cream. But if you keep shaking the 0:03:50.250 --> 0:03:54.450 mixture up, breaking apart more micelles, eventually you expose enough 0:03:54.510 --> 0:03:58.950 fats that they can clump together and push the water out. Begone, 0:03:58.990 --> 0:04:03.780 foul beast. This is inverting the emulsion. It's also called 0:04:03.790 --> 0:04:08.160 the churning process. When you're done, you're left with clumps 0:04:08.220 --> 0:04:12.360 of butterfat surrounded by buttermilk. That is, that water and 0:04:12.460 --> 0:04:17.060 water-soluble milk stuff. you then work or knead the clumps 0:04:17.100 --> 0:04:21.520 together to press out more liquid. So that's your concentrated 0:04:21.580 --> 0:04:26.390 butter fat, but remember how I mentioned that butter is crystallized? Okay, 0:04:26.410 --> 0:04:28.830 the physics of this part get a little complicated, and 0:04:29.070 --> 0:04:32.710 I was an English major, but here's how I understand it. Basically, 0:04:33.130 --> 0:04:36.170 the wee particles of fats that start out wrapped up 0:04:36.290 --> 0:04:40.440 cozy inside their micelles can be either liquid or crystalline 0:04:40.510 --> 0:04:45.310 in structure, depending on their temperature. There's a wide range 0:04:45.370 --> 0:04:50.010 of freezing transformation points for fats, but again, basically, butter 0:04:50.029 --> 0:04:55.650 fats start crystallizing at around 50 degrees Fahrenheit, or 10 Celsius. So, 0:04:55.980 --> 0:04:59.220 in cream that has been cooled before churning, you've got 0:04:59.240 --> 0:05:03.940 a mixture of both liquid and crystal fat particles. Those 0:05:04.020 --> 0:05:07.180 microstructures interact with each other, especially as the butter is 0:05:07.300 --> 0:05:10.500 churned and worked, and the liquids will stick to the crystals. 0:05:11.750 --> 0:05:14.530 To get the consistency of your final butter just right, 0:05:14.550 --> 0:05:18.550 neither melty and greasy nor stiff and flaky, you want 0:05:18.570 --> 0:05:21.250 to get your mix of liquid and crystal fats just right. 0:05:22.050 --> 0:05:24.770 The exact way that you cool the cream is important, 0:05:25.150 --> 0:05:27.310 and the way that you cool the butter after churning 0:05:27.529 --> 0:05:32.130 is important. Before the advent of machinery and gauges to 0:05:32.190 --> 0:05:36.099 achieve these factors precisely, butter probably did feel a lot 0:05:36.130 --> 0:05:39.849 like magic. There's actually been a bunch of super in-depth 0:05:39.930 --> 0:05:43.630 physics research into exactly how these butter microstructures work, which 0:05:43.710 --> 0:05:48.290 is fabulous. But okay, that is the basic process for 0:05:48.330 --> 0:05:52.929 making butter. Churning, working, and simultaneous cooling all the while. 0:05:54.150 --> 0:05:56.830 But there are a bunch of different types of butter available. 0:05:57.480 --> 0:05:59.760 On grocery shelves in the U.S., you can usually find 0:05:59.779 --> 0:06:05.160 varieties including sweet cream, salted or unsalted, cultured, and European. 0:06:06.630 --> 0:06:09.200 Sweet cream unsalted butter is the type that a lot 0:06:09.220 --> 0:06:11.900 of American cooks and bakers will reach for when they're 0:06:11.920 --> 0:06:15.700 looking for a light, slightly sweet buttery flavor, and if 0:06:15.720 --> 0:06:18.419 they prefer to add their own salt to recipes to taste. 0:06:19.680 --> 0:06:23.180 But this is a newfangled invention, born of the industrial 0:06:23.420 --> 0:06:28.330 age of pasteurization, refrigeration, and the speedy mechanical separation of 0:06:28.470 --> 0:06:33.310 cream from milk. Prior to the 1880s, all butter would 0:06:33.330 --> 0:06:37.520 have been either salted or cultured or both. Butter is 0:06:37.750 --> 0:06:43.710 traditionally a cultured, that is, fermented, product. Like other common foods, 0:06:43.890 --> 0:06:48.410 like yogurt, cheese, sourdough bread, and pickles, some of butter's 0:06:48.470 --> 0:06:53.650 characteristics originally came from fermentation with friendly lactic acid bacteria. 0:06:54.940 --> 0:06:57.700 This category of bacteria eat some of the sugars in 0:06:57.760 --> 0:07:01.940 milk and excrete acids. Those acids help out in a 0:07:01.980 --> 0:07:05.040 few ways. At first, they can make the milk or 0:07:05.100 --> 0:07:08.960 cream an unwelcome environment for unfriendly microbes that might make 0:07:09.000 --> 0:07:13.220 you sick. Also, the acids help break up the globules 0:07:13.320 --> 0:07:17.100 in the cream, making churning easier, and give a slight 0:07:17.220 --> 0:07:21.940 tangy flavor to the finished butter. Lactic acid bacteria live 0:07:22.040 --> 0:07:26.120 all around us, so prior to pasteurization and refrigeration, they 0:07:26.140 --> 0:07:28.660 would have naturally gone to work on milk and cream 0:07:28.720 --> 0:07:32.510 before it was made into butter. These days, cultured butter 0:07:32.610 --> 0:07:35.690 is usually made from cream that's been pasteurized to peel 0:07:35.750 --> 0:07:39.340 off any potentially harmful microbes, and then specific strains of 0:07:39.400 --> 0:07:42.580 lactic acid bacteria are added on purpose to culture it. 0:07:43.960 --> 0:07:47.560 Sweet cream butter is made without culturing. Most of what 0:07:47.600 --> 0:07:51.550 we consider butter flavor actually comes from lactic acid bacteria. 0:07:52.090 --> 0:07:56.330 They also excrete diacetyl, which is the compound that tastes buttery. 0:07:57.380 --> 0:08:00.900 Diacetyl is sometimes added to sweet cream butter to make 0:08:00.940 --> 0:08:04.880 it taste like butter. This compound is also at work 0:08:04.980 --> 0:08:08.640 in other products of fermentation. It's what makes some chardonnays 0:08:08.790 --> 0:08:13.430 taste buttery, for example. Salt was traditionally not as much 0:08:13.470 --> 0:08:17.210 a flavoring as another way to preserve butter before refrigeration. 0:08:18.350 --> 0:08:21.240 Just like us, the microbes that spoil food need water 0:08:21.300 --> 0:08:25.560 to live, so salt can really muck them around. But 0:08:25.620 --> 0:08:29.340 because most butter today is made from pasteurized cream, salt 0:08:29.480 --> 0:08:33.240 is added as an optional flavoring. These days, butter may 0:08:33.280 --> 0:08:37.860 also be colored during manufacturing. The yellow of butter comes 0:08:37.920 --> 0:08:42.319 from fresh grass in cows' diets. And I know, grass 0:08:42.400 --> 0:08:46.500 is green, not yellow, but it contains beta-carotene, you know, 0:08:46.620 --> 0:08:49.580 that useful compound that our bodies convert to vitamin A 0:08:50.220 --> 0:08:53.260 and that gives a lot of orangey plants like pumpkins 0:08:53.300 --> 0:08:57.040 and carrots their rich color. It's locked up in grass 0:08:57.100 --> 0:08:59.699 so you can't see it, but it does get transferred 0:08:59.740 --> 0:09:04.179 to cow's milk. And I know cow's milk is white, 0:09:04.820 --> 0:09:09.560 but beta-carotene is a fat-soluble compound. In milk, it's locked 0:09:09.600 --> 0:09:12.340 up in the fat molecules, which are themselves locked up 0:09:12.400 --> 0:09:16.459 in micelles. Or rather, they are, until you start messing 0:09:16.480 --> 0:09:20.959 with those micelles during the churning process. So milk from 0:09:21.000 --> 0:09:23.800 cows fed on more fresh grass, which is only available 0:09:23.820 --> 0:09:27.510 in the summer, is will create yellower butter. This is 0:09:27.530 --> 0:09:30.320 also what makes some cheeses yellow or orange in color. 0:09:31.580 --> 0:09:34.559 When cows are given less fresh grass, maybe because they 0:09:34.620 --> 0:09:37.800 aren't allowed to pasture graze, or maybe because it's winter, 0:09:38.440 --> 0:09:43.699 that butter will be whiter. So, for consistency or preference, 0:09:44.040 --> 0:09:47.540 or to fib about their quality in feeding practices, some 0:09:47.600 --> 0:09:53.490 brands color their butter. The same thing happens with some cheeses, too. Okay. 0:09:54.070 --> 0:09:57.980 But what about European butter? Folks outside of Europe might 0:09:58.020 --> 0:10:02.660 have seen fancy-looking and often fancy-priced packages of foil-wrapped butter 0:10:02.720 --> 0:10:05.300 in your grocery store or on your favorite cooking show 0:10:05.660 --> 0:10:09.910 and wondered what the hubbub is about. Different governments regulate 0:10:09.950 --> 0:10:13.530 foods differently, which is perhaps obvious, but those details can 0:10:13.650 --> 0:10:18.040 and do impact a finished product. The European Union's rules 0:10:18.080 --> 0:10:23.350 for butter include that it must contain at least 82% butterfat. U.S. 0:10:23.400 --> 0:10:28.309 regulations require only 80% butterfat. It sounds small, but it 0:10:28.330 --> 0:10:32.470 can absolutely make a difference in a dish. European butters, 0:10:32.710 --> 0:10:36.090 and particularly ones that get exported and sold in specialty stores, 0:10:36.490 --> 0:10:39.290 are also more likely to be cultured and tangy, and 0:10:39.309 --> 0:10:43.880 to have more noticeable grassy or pasture flavors. Of course, 0:10:44.040 --> 0:10:47.100 producers outside of Europe, like in the States, can make 0:10:47.280 --> 0:10:51.120 higher-fat and more flavorful butters, too. Check your labels if 0:10:51.160 --> 0:10:54.939 you're looking for something special for a particular use. If 0:10:54.980 --> 0:10:56.780 you want to, you can even make your own butter 0:10:56.820 --> 0:10:59.700 at home. You don't even need a churn. You can 0:10:59.720 --> 0:11:02.520 just shake a cup of heavy cream in a quart-sized 0:11:02.590 --> 0:11:05.470 mason jar for about 15 minutes, or until the butter 0:11:05.500 --> 0:11:08.430 forms up. Then rinse it with cold water a couple 0:11:08.450 --> 0:11:11.189 of times and knead it until the pockets of air 0:11:11.290 --> 0:11:15.090 and water work themselves out. Some parents report that this 0:11:15.150 --> 0:11:16.410 is a good way to get a kid involved in 0:11:16.429 --> 0:11:20.510 the kitchen. This is also a micro-scale version of the 0:11:20.610 --> 0:11:26.500 traditional industrial process, which goes something like this. First, cream 0:11:26.580 --> 0:11:30.000 is separated out from whole milk and pasteurized, then cooled. 0:11:30.679 --> 0:11:34.340 Then it is time for churning. Churns these days are 0:11:34.440 --> 0:11:38.240 huge aluminum drums spun on the horizontal axis by motors, 0:11:38.800 --> 0:11:42.260 like a clothes dryer. A clothes dryer that fits thousands 0:11:42.280 --> 0:11:45.760 of gallons of stuff inside. the cream is piped in 0:11:45.900 --> 0:11:48.959 and you start spinning the churn. There's often a porthole 0:11:49.020 --> 0:11:50.970 on one end of the cylinder, so you can keep 0:11:51.000 --> 0:11:54.490 an eye on things. Within an hour, the fats come 0:11:54.510 --> 0:11:58.350 together and the liquids separate out. You then drain off 0:11:58.370 --> 0:12:01.070 the buttermilk and sometimes rinse the butter with cold water. 0:12:02.030 --> 0:12:04.710 After that, you start the butterfat spinning again to work 0:12:04.750 --> 0:12:07.990 it further and to mix in any flavorings or colorings. 0:12:09.270 --> 0:12:12.150 The butter clumps together into a huge mass, which you 0:12:12.170 --> 0:12:14.719 then pull or spin out of the drum and weigh 0:12:14.780 --> 0:12:17.800 out into batches, and mold and package for industry and 0:12:17.860 --> 0:12:23.660 consumer use. Industrial producers may be handling between 1,500 to 0:12:23.660 --> 0:12:28.280 5,000 pounds of butter per batch, which is about 700 0:12:28.280 --> 0:12:33.170 to 2,300 kilos, which is a lot. By the way, 0:12:33.390 --> 0:12:36.929 going back to buttermilk. Although any liquid that comes off 0:12:36.970 --> 0:12:40.550 of butter during the butter-making process is technically buttermilk, the 0:12:40.590 --> 0:12:45.160 term refers specifically to soured, that is, cultured butter liquids. 0:12:46.040 --> 0:12:50.070 And because most American butter is not cultured, generally, the 0:12:50.110 --> 0:12:53.110 buttermilk that's sold in the U.S. is not a byproduct 0:12:53.250 --> 0:12:57.219 of the butter-making process. It's just milk that's been soured 0:12:57.290 --> 0:13:00.520 by adding lactic acid and maybe a thickener to change 0:13:00.540 --> 0:13:05.059 the consistency. And finally, if you came here wondering about 0:13:05.100 --> 0:13:10.120 the nutritional science of butter... Nutrition is always complicated, and 0:13:10.150 --> 0:13:13.220 the story of how our bodies process different fats, and 0:13:13.360 --> 0:13:16.520 why there's so much confusion about that, is nuanced enough 0:13:16.600 --> 0:13:19.640 that it deserves its own episode. And that's on my list. 0:13:20.240 --> 0:13:24.940 But very basically, butter is a calorie-dense food. It's just 0:13:25.000 --> 0:13:28.400 fine to eat unless a healthcare professional has told you otherwise. 0:13:28.900 --> 0:13:36.850 Just don't overdo it. Today's episode was written by me, 0:13:37.070 --> 0:13:40.670 Lauren Vogelbaum. BrainStuff is a production of iHeart Podcasts in 0:13:40.720 --> 0:13:44.540 partnership with HowStuffWorks.com and is produced by Tyler Klang. For 0:13:44.580 --> 0:13:47.520 more shows from iHeart Podcasts, visit the iHeart Radio app, 0:13:47.850 --> 0:13:50.809 Apple Podcasts, or wherever you listen to your favorite shows.