WEBVTT - Why are the ice cream machines at McDonald's "always" broken? 0:00:04.440 --> 0:00:12.319 Welcome to tech Stuff, a production from iHeartRadio. Hey there, 0:00:12.320 --> 0:00:15.680 and welcome to tech Stuff. I'm your host Jonathan Strickland. 0:00:15.680 --> 0:00:19.079 I'm an executive producer with iHeartRadio and how the tech 0:00:19.120 --> 0:00:22.480 are you so. Over the last couple of years, I've 0:00:22.560 --> 0:00:26.840 talked a lot about the concept of right to repair. 0:00:27.000 --> 0:00:29.400 In fact, I've talked about it this week simply, but 0:00:30.040 --> 0:00:32.920 the right to repair is all about giving individuals the 0:00:33.000 --> 0:00:35.760 right to perform their own maintenance and repair on the 0:00:35.760 --> 0:00:39.040 products that they buy, rather than being forced to go 0:00:39.120 --> 0:00:44.680 through some official channel from the manufacturer itself. So a 0:00:44.720 --> 0:00:47.919 lot of hardware companies will lock down their products in 0:00:47.960 --> 0:00:51.640 ways that make it difficult or sometimes even impossible for 0:00:51.760 --> 0:00:56.000 the average person or independent repair shop to do maintenance 0:00:56.120 --> 0:00:59.480 or repair on their products. A company could use stuff 0:00:59.600 --> 0:01:04.440 like dietary fasteners, for example, that require specialized tools to 0:01:04.480 --> 0:01:08.040 remove them, or the company might not provide any useful 0:01:08.080 --> 0:01:12.280 documentation on how their technology works or what to do 0:01:12.319 --> 0:01:15.160 if something goes wrong. And if you don't know how 0:01:15.200 --> 0:01:17.800 something works, you really don't have a way to fix 0:01:17.840 --> 0:01:20.920 it when it's not working. There are lots of ways 0:01:21.040 --> 0:01:24.880 that a company might lock down a product. It's not 0:01:24.959 --> 0:01:29.000 unusual in the world of vehicles, from automobiles to heavy 0:01:29.040 --> 0:01:32.120 farm equipment, for a company to tie everything into a 0:01:32.160 --> 0:01:36.040 computer system, and that computer system is more or less 0:01:36.040 --> 0:01:39.080 inaccessible unless you have the right equipment and knowledge to 0:01:39.160 --> 0:01:42.400 tap into it. So these are all examples of almost 0:01:42.400 --> 0:01:46.199 turning products into black boxes. And meanwhile you have people 0:01:46.200 --> 0:01:48.560 who say, I want to be able to fix this 0:01:48.680 --> 0:01:51.000 if something goes wrong and not have to bring it 0:01:51.360 --> 0:01:54.080 all the way back to some official store. Now, a 0:01:54.080 --> 0:01:56.640 lot of companies will actually tell you the reason that 0:01:56.680 --> 0:01:58.919 they even do this, that they do all this locking 0:01:58.960 --> 0:02:05.080 away stuff is for your own good. Take Apple for example. Traditionally, 0:02:05.520 --> 0:02:09.800 Apple had argued that locking down its systems really keeps 0:02:09.840 --> 0:02:13.880 customers safe because Apple can guarantee a high level of service. 0:02:14.280 --> 0:02:16.480 And if just any Yahoo out there could open up 0:02:16.480 --> 0:02:19.000 an iPhone and make changes, then who knows what evil 0:02:19.080 --> 0:02:22.400 doers would get up to. Maybe you would think that 0:02:22.520 --> 0:02:25.079 you're taking your phone to get your battery swapped out, 0:02:25.360 --> 0:02:28.880 but what's really happening is Joe Schmo of Joe Schmo's 0:02:28.880 --> 0:02:33.600 iPhone and VCR repair is actually installing like geo trackers 0:02:33.639 --> 0:02:38.200 on your device or something. Other companies like e bike companies, 0:02:38.240 --> 0:02:40.800 I talked about this this week. They have argued that 0:02:40.880 --> 0:02:44.320 any repairs that are done outside the company's own ecosystem 0:02:44.840 --> 0:02:49.160 could lead to dangerous situations like a fire. And it's 0:02:49.200 --> 0:02:52.760 true that some electric vehicles, you know, stuff like hoverboards 0:02:52.760 --> 0:02:57.080 and even some e bikes have been involved in some fires, 0:02:57.080 --> 0:03:00.520 some of them really catastrophic ones. But these fires typically 0:03:00.520 --> 0:03:06.359 result from poor manufacturing processes and damage to batteries. And 0:03:06.680 --> 0:03:08.799 in this case, you talk about a battery where you've 0:03:08.840 --> 0:03:12.079 got a flaw somewhere that creates a short circuit inside 0:03:12.160 --> 0:03:15.880 the battery itself. It is a pathway through which the 0:03:16.120 --> 0:03:20.960 electrochemical system that can generate electricity has a shortcut. It 0:03:21.040 --> 0:03:24.520 bypasses everything else. This leads to the battery overheating very 0:03:24.600 --> 0:03:29.799 quickly and in some cases exploding into flame. But again 0:03:30.360 --> 0:03:33.600 that's not necessarily because some e bike owner decided they 0:03:33.600 --> 0:03:36.400 were going to replace a battery on their own. More 0:03:36.440 --> 0:03:38.600 often than not, it happens because there's a flaw in 0:03:38.640 --> 0:03:43.480 the actual manufacturing process and the owner had nothing to 0:03:43.480 --> 0:03:46.640 do with it whatsoever. In fact, in yesterday's news episode, 0:03:46.680 --> 0:03:50.360 I talked about how a representative for the lobbying organization 0:03:50.520 --> 0:03:54.080 called People for Bikes, which by the way, represents the 0:03:54.120 --> 0:03:59.240 bike industry. It doesn't represent the bicyclist community anyway. This 0:03:59.320 --> 0:04:05.440 representative couldn't give evidence of this being a situation at all. Instead, 0:04:06.040 --> 0:04:10.000 this person said the evidence was quote unquote anecdotal. Does 0:04:10.040 --> 0:04:12.480 this mean that it would be impossible for someone to 0:04:12.520 --> 0:04:15.240 accidentally cause a fire while trying to repair their own 0:04:15.280 --> 0:04:19.239 e bike? No, it would be possible, but it isn't 0:04:19.279 --> 0:04:23.960 something that's actually been documented. So the reason for the 0:04:24.000 --> 0:04:27.839 policy is based upon something that hasn't been proven to 0:04:27.880 --> 0:04:30.960 actually happen. You know, it's like one of those protective measures, 0:04:31.000 --> 0:04:33.599 and you're saying, but if the thing that it's protecting 0:04:33.680 --> 0:04:38.120 against hasn't happened, how is it protecting anyone other than 0:04:38.160 --> 0:04:42.560 your own interests? Anyway. A big reason why companies actually 0:04:42.560 --> 0:04:45.880 do this is that it makes them a lot more money. 0:04:46.160 --> 0:04:50.720 A company like Apple, by controlling the entire ecosystem, can 0:04:50.760 --> 0:04:54.760 make money throughout the whole life cycle of your Apple device. 0:04:55.279 --> 0:04:58.200 So let's say it's an iPhone. Well, first, Apple gets 0:04:58.240 --> 0:05:01.720 money when you buy your eye phone. They get money 0:05:02.000 --> 0:05:05.400 if you pay for Apple Care. They also make money 0:05:05.440 --> 0:05:07.480 if you don't have Apple Care, and then you have 0:05:07.520 --> 0:05:10.599 to bring the phone into an Apple store for repairs, 0:05:11.600 --> 0:05:14.840 or they make money by granting a license to repair 0:05:14.880 --> 0:05:17.520 shops that pay for the privilege of being able to 0:05:17.560 --> 0:05:21.760 work on Apple devices. By controlling the big picture, Apple 0:05:21.800 --> 0:05:26.400 can generate revenue the whole time. There's every touch point 0:05:26.480 --> 0:05:30.320 is a place where Apple makes money. So recently, Apple 0:05:30.360 --> 0:05:33.320 has actually backed off of this a little bit. The 0:05:33.360 --> 0:05:36.360 company has started to offer a self service repair kit, 0:05:36.760 --> 0:05:39.560 which includes some of the tools needed to access the 0:05:39.640 --> 0:05:43.599 innerds of stuff like iPhones, and you can purchase a kit, 0:05:43.760 --> 0:05:46.440 or you can rent one for a week. You know, 0:05:46.480 --> 0:05:48.800 if you're someone who doesn't need to own one of 0:05:48.839 --> 0:05:50.320 these kits, you could just rent it for a week 0:05:50.360 --> 0:05:52.640 for like fifty bucks and then use it to do 0:05:52.680 --> 0:05:56.440 your own repairs. You can also purchase replacement parts from 0:05:56.480 --> 0:06:00.839 Apple and repair manuals Apples providing those as well. It's 0:06:00.880 --> 0:06:04.400 not exactly cheap, and if you're just working on your 0:06:04.400 --> 0:06:07.159 own device, you might eventually come to the conclusion that 0:06:07.200 --> 0:06:10.080 it would actually be less hassle and less expensive to 0:06:10.080 --> 0:06:13.520 bring your device into Apple anyway. But if you're an 0:06:13.560 --> 0:06:16.080 independent repair shop owner, the program could make a lot 0:06:16.120 --> 0:06:20.720 of financial sense anyway. The whole reason that I'm bringing 0:06:20.760 --> 0:06:22.960 this up again is to talk about something that has 0:06:23.040 --> 0:06:25.919 been a long standing issue, one that has led to 0:06:26.120 --> 0:06:30.119 endless jokes and posts and memes and videos of people 0:06:30.200 --> 0:06:33.000 really frustrated as they go through drive through I'm talking 0:06:33.000 --> 0:06:36.400 about the much maligned ice cream machines at the fast 0:06:36.400 --> 0:06:40.360 food chain McDonald's. So the company I fix It, which 0:06:40.400 --> 0:06:41.880 I love, by the way, I fix It, is a 0:06:41.920 --> 0:06:44.800 phenomenal resource. If you want to learn how stuff works, 0:06:45.839 --> 0:06:48.800 check out I fix it because they have these detailed 0:06:48.960 --> 0:06:53.600 repair sections on all these different devices and as a result, 0:06:53.680 --> 0:06:56.760 you will learn how those devices work. You have to again, 0:06:56.920 --> 0:06:58.279 if you want to be able to fix something, you 0:06:58.279 --> 0:07:00.680 gotta know how it works in the first place. It 0:07:00.720 --> 0:07:05.200 does get very technical, but it is incredibly detailed. Anyway, 0:07:05.480 --> 0:07:08.160 I fix It has been documenting how to repair all 0:07:08.240 --> 0:07:11.240 types of technology for years, and they recently did a 0:07:11.240 --> 0:07:14.720 piece on the ice cream machines at McDonald's and it's 0:07:14.720 --> 0:07:18.320 actually well worth checking out their YouTube video on the subject. 0:07:18.320 --> 0:07:24.000 It is really fantastic. It's entertaining and informative, and it's 0:07:24.040 --> 0:07:26.400 you know, like just like ten minutes long. It's not 0:07:26.920 --> 0:07:29.400 long at all, so it's really worth checking out. So 0:07:29.920 --> 0:07:31.480 some of the stuff I'm going to talk about will 0:07:31.520 --> 0:07:34.240 overlap what they cover in that video, but I'm also 0:07:34.280 --> 0:07:37.200 looking at some other things as well. Now, the issue 0:07:37.280 --> 0:07:42.280 here is that there's this essentially a perception more but 0:07:42.360 --> 0:07:45.040 really based in reality, that the ice cream machines at 0:07:45.080 --> 0:07:48.840 McDonald's are quote unquote always broken. So I fix it 0:07:48.920 --> 0:07:51.440 found that this perception has at least some merit to it, 0:07:51.480 --> 0:07:56.000 because at any given time, according to various tools online, 0:07:56.440 --> 0:07:59.680 around a third of McDonald's franchises have an ice cream 0:07:59.720 --> 0:08:03.760 machine that's not currently working, which almost makes it sound 0:08:03.800 --> 0:08:07.760 like it's a conspiracy. So what's going on here? Well, 0:08:07.800 --> 0:08:10.200 to answer that, we have to learn a little bit 0:08:10.240 --> 0:08:14.160 about the company that provides those ice cream machines. Once 0:08:14.240 --> 0:08:17.240 upon a time, it was called the Tailor Freezer Corporation. 0:08:17.800 --> 0:08:21.520 Now it's just known as the Tailor Company. And way 0:08:21.560 --> 0:08:24.679 back in nineteen twenty six, a man named Charles Taylor, 0:08:24.800 --> 0:08:28.840 whom the company describes as a third generation ice cream maker, 0:08:29.440 --> 0:08:32.679 wanted to create a means of making ice cream without 0:08:32.720 --> 0:08:36.360 having to hand crank a device, and to guarantee better 0:08:36.440 --> 0:08:40.560 consistency between ice cream batches. I guess it would benefit 0:08:40.640 --> 0:08:44.280 us to first understand how ice cream actually you know 0:08:45.040 --> 0:08:50.280 happens which involves some physics and some chemistry. So essentially, 0:08:51.040 --> 0:08:54.040 you need to take your ice cream mixture, which typically 0:08:54.040 --> 0:08:58.240 includes ingredients like sugar, milk, and fat, and then any 0:08:58.240 --> 0:09:02.280 other flavorings that you want, and you might be using 0:09:02.280 --> 0:09:05.160 something like heavy cream to provide the fat, and you 0:09:05.240 --> 0:09:09.280 want to freeze this mixture. But the structure of this liquid, 0:09:09.520 --> 0:09:11.800 you know, in order to get to crystallize, it actually 0:09:11.880 --> 0:09:15.480 requires a lower freezing point than what we get using 0:09:16.000 --> 0:09:19.440 just ice, and that presents a challenge. How do you 0:09:19.480 --> 0:09:22.839 get a mixture to a cold enough temperature to freeze, 0:09:23.640 --> 0:09:25.960 particularly if you want to make ice cream during the 0:09:26.080 --> 0:09:29.160 dog days of summer, how do you get that mixture 0:09:29.240 --> 0:09:33.280 colder than the temperature of ice. If you've ever used 0:09:33.280 --> 0:09:36.160 an old fashioned ice cream churn, you know, the hand 0:09:36.160 --> 0:09:40.680 cranked kind, you know that you pack the perimeter of 0:09:40.720 --> 0:09:43.560 the churn like there's a gap inside the churn between 0:09:43.559 --> 0:09:46.120 the outer wall and the ice cream chamber, right, and 0:09:46.160 --> 0:09:50.560 you pack that with a mixture of ice and salt. 0:09:50.920 --> 0:09:54.920 Why do you use salt? What does the salt do well? 0:09:55.000 --> 0:09:59.319 Salt lowers the freezing point for water if you're talking 0:09:59.360 --> 0:10:02.520 about pure water, that of course freezes at zero degrees 0:10:02.600 --> 0:10:06.240 celsius or thirty two degrees fahrenheit. When you introduce salt 0:10:06.440 --> 0:10:10.200 to water, it will require a lower temperature for that 0:10:10.280 --> 0:10:13.120 water to freeze. How much lower depends upon the concentration 0:10:13.200 --> 0:10:16.000 of salt. So this is also why people will salt 0:10:16.240 --> 0:10:20.520 roads and walkways either before or during a snow or 0:10:20.559 --> 0:10:23.320 ice storm. It lowers the freezing point. That means the 0:10:23.320 --> 0:10:26.319 ice will actually start to melt at a lower temperature 0:10:26.360 --> 0:10:29.680 than it normally would. So if you're on a winter day, 0:10:30.240 --> 0:10:33.920 maybe the high temperature is going to be like twenty 0:10:34.000 --> 0:10:37.880 eight degrees well fahrenheit. Twenty eight degrees fahrenheit is still 0:10:37.920 --> 0:10:40.560 below the freezing point for water, right, and so typically 0:10:40.600 --> 0:10:43.120 the frozen roads would remain frozen. But if you put 0:10:43.880 --> 0:10:47.400 salt on those roads, it will lower the freezing point 0:10:47.400 --> 0:10:49.840 of water, and maybe you get it down so that 0:10:49.880 --> 0:10:52.200 the freezing point of water would be twenty degrees fahrenheit. 0:10:52.280 --> 0:10:54.320 And since you're high at twenty eight, it means the 0:10:54.320 --> 0:10:57.240 ice will actually start to melt. So that's why we 0:10:57.280 --> 0:11:01.480 add salt to roads in the way times. On a 0:11:01.520 --> 0:11:04.280 molecular level, what's going on is that the salt is 0:11:04.320 --> 0:11:08.359 interfering with the water ability to form the crystalline structure 0:11:08.800 --> 0:11:11.520 of ice. So that means the freezing point has to 0:11:11.520 --> 0:11:13.760 go down in order to get a temperature low enough 0:11:13.760 --> 0:11:18.760 to overcome salt inhibiting the water in this way, and again, 0:11:18.800 --> 0:11:22.200 the concentration of salt will determine exactly how low you 0:11:22.240 --> 0:11:25.280 have to get before the water will freeze. But what 0:11:25.320 --> 0:11:27.640 does that mean for our ice cream? Well, let's imagine 0:11:27.679 --> 0:11:32.200 the ice cream maker is an enclosed thermal system. The 0:11:32.440 --> 0:11:36.400 ice and salt mixture is at a lower temperature than 0:11:36.520 --> 0:11:38.800 the ice cream mixture, right Like, let's say we've poured 0:11:38.800 --> 0:11:40.880 the ice cream mixture in, it's more or less at 0:11:40.920 --> 0:11:47.000 room temperature, and the surrounding ice and salt mixture is 0:11:47.120 --> 0:11:50.440 closer to the freezing point for water, so it's closer 0:11:50.440 --> 0:11:53.520 to zero degrees celsius. We know that the laws of 0:11:53.520 --> 0:11:56.360 thermo dynamic state that if you have stuff that is 0:11:56.800 --> 0:12:01.480 of different energy levels, the system will tend toward an equilibrium. 0:12:01.640 --> 0:12:04.319 And that we know that energy has to flow from 0:12:04.440 --> 0:12:08.960 high concentrations to low concentrations. It can't go the other way. 0:12:09.320 --> 0:12:11.319 Energy can't go from low to high. It has to 0:12:11.400 --> 0:12:15.720 go from high to low. So our ice mixture begins 0:12:15.760 --> 0:12:19.520 to melt, so the heat from our ice cream mixture 0:12:19.559 --> 0:12:23.360 starts to transfer to the outer part of the ice 0:12:23.360 --> 0:12:28.199 cream chamber. That heat transfers to the ice and salt mixture, 0:12:28.760 --> 0:12:32.120 and so the ice is absorbing heat and thus the 0:12:32.160 --> 0:12:36.400 temperature of the ice cream mixture is going down. So 0:12:38.080 --> 0:12:40.839 it then is going to need to get cold enough 0:12:40.880 --> 0:12:43.040 to freeze that ice cream mixture. If we were just 0:12:43.240 --> 0:12:46.439 using ice, we wouldn't get there because the temperature we 0:12:46.480 --> 0:12:49.160 would be at would be essentially zero degrees celsius or 0:12:49.160 --> 0:12:51.800 thirty two degrees fahrenheit. It wouldn't be cold enough to 0:12:51.840 --> 0:12:54.200 get to the temperature that would be required to turn 0:12:54.200 --> 0:12:57.120 the ice cream mixture into actual ice cream. But the 0:12:57.160 --> 0:12:59.800 salt we've added has lowered the freezing point for the 0:12:59.800 --> 0:13:03.000 ice ice in the churn. This is important. Let's think 0:13:03.040 --> 0:13:06.880 about the different phases of water in terms of energy, right. 0:13:06.960 --> 0:13:10.880 So ice is water with its low energy point at 0:13:10.920 --> 0:13:15.000 this stage. In this phase, water molecules are in that 0:13:15.080 --> 0:13:19.120 crystalline structure. They pretty much stop moving, so they are 0:13:19.240 --> 0:13:22.160 very low energy. So we can then think of liquid 0:13:22.200 --> 0:13:26.040 water as water that has a medium energy phase. In 0:13:26.040 --> 0:13:28.600 this phase, the water molecules can move around, and they do, 0:13:28.800 --> 0:13:31.160 and water will also take the shape of whatever container 0:13:31.160 --> 0:13:34.200 it's in, So stuff is happening when it's in liquid form. 0:13:34.920 --> 0:13:37.560 If we were to go even warmer and increase the 0:13:37.679 --> 0:13:41.120 energy more, then we would have the water evaporate into gas, 0:13:41.200 --> 0:13:43.080 and then it would be at a very high energy phase. 0:13:43.320 --> 0:13:45.520 Those molecules would be zipping around all over the place. 0:13:45.760 --> 0:13:49.640 But anyway, our ice, the solid water starts to melt, 0:13:49.960 --> 0:13:52.280 but the salt we've added has lowered that freezing point 0:13:52.320 --> 0:13:55.920 to below zero celsius or thirty two fahrenheit. Meanwhile, we 0:13:56.000 --> 0:14:00.240 have this salty water that's inside the churn, and that 0:14:00.280 --> 0:14:03.040 salty water is going to continue to transfer energy to 0:14:03.080 --> 0:14:05.840 the ice because remember the liquid water has a higher 0:14:06.000 --> 0:14:09.360 energy than the solid water does than the ice does, 0:14:09.920 --> 0:14:12.400 So the decreased freezing point means that the liquid water 0:14:12.440 --> 0:14:16.640 will actually keep giving energy to the ice even below 0:14:16.800 --> 0:14:20.320 the normal point for freezing, because you know, as it's 0:14:20.360 --> 0:14:25.280 transferring heat to the ice, the liquid water's temperature continues 0:14:25.320 --> 0:14:28.120 to drop, and now the freezing point is lower, so 0:14:28.160 --> 0:14:32.480 it remains freezing longer and you end up getting this salty, 0:14:33.000 --> 0:14:37.000 icy slurry inside the churn that gets to a much 0:14:37.040 --> 0:14:42.120 lower temperature than the freezing point for water, and thus 0:14:42.360 --> 0:14:45.280 you can have a low enough temperature where the ice 0:14:45.320 --> 0:14:48.640 cream mixture inside the chamber will reach a temperature low 0:14:48.760 --> 0:14:52.360 enough to start to crystallize and become ice cream. So yeah, 0:14:52.640 --> 0:14:56.720 it's really cool that it works this way just by 0:14:56.800 --> 0:15:00.040 using salt and ice. And I gotta tell you, like, 0:15:01.040 --> 0:15:03.320 it's been so long since I've had basic physics that 0:15:03.360 --> 0:15:05.280 it took me a while to really get my mind 0:15:05.280 --> 0:15:08.920 wrapped around this, because it seems like it seems almost 0:15:08.920 --> 0:15:11.320 counterintuitive in some ways, but as you think about it, 0:15:11.320 --> 0:15:13.200 you start to realize, oh, it makes sense. You're just 0:15:13.240 --> 0:15:14.800 thinking about the wrong way, or at least for me. 0:15:15.240 --> 0:15:17.360 I'm not suggesting you thought of it that way, but 0:15:17.400 --> 0:15:20.360 for me, it was like there was a little block there. Anyway, 0:15:20.480 --> 0:15:22.440 these days, a lot of ice cream makers use other 0:15:22.440 --> 0:15:24.960 stuff to chill the mixture down low enough for it 0:15:25.000 --> 0:15:28.840 to freeze. And in fact, if you're looking at industrial ones, 0:15:28.880 --> 0:15:31.960 you're typically looking at a device that uses condensers and 0:15:32.040 --> 0:15:36.240 refrigerant to build in a sort of heat exchanger. It's 0:15:36.280 --> 0:15:38.800 the same as you would find in a refrigerator or 0:15:38.840 --> 0:15:41.400 an air conditioner. And I've talked about this process a 0:15:41.440 --> 0:15:44.560 lot too, but we will cover that a little bit 0:15:44.720 --> 0:15:56.400 when we come back from this quick break. Okay, before 0:15:56.440 --> 0:15:59.880 the break, I mentioned a heat exchanger, the kind of 0:16:00.040 --> 0:16:02.160 you would find in a refrigerator or you know, like 0:16:02.200 --> 0:16:06.840 an industrial freezer, that kind of stuff, including ice cream machines, 0:16:07.160 --> 0:16:09.840 and how do these work well. They also take advantage 0:16:10.000 --> 0:16:15.080 of the physics of different phases of a material, in 0:16:15.080 --> 0:16:18.400 this case a refrigerant, a liquid, or a liquid that 0:16:18.560 --> 0:16:20.920 also in some parts of the system is a gas. 0:16:21.280 --> 0:16:28.040 So when a liquid evaporates, that liquid absorbs heat. This 0:16:28.200 --> 0:16:31.080 is why when you have water on your skin and 0:16:31.160 --> 0:16:34.680 it starts to evaporate off your skin, it feels cool 0:16:35.040 --> 0:16:38.120 because the water is absorbing heat from your body as 0:16:38.200 --> 0:16:43.680 part of that evaporation process. When water condenses, then it 0:16:43.800 --> 0:16:47.360 releases heat. So when a gas condenses into a liquid, 0:16:47.920 --> 0:16:50.800 it is releasing heat. When it's a liquid that it's 0:16:50.800 --> 0:16:53.920 a vaporing into a gas, it absorbs heat. So if 0:16:53.960 --> 0:16:57.160 you create a system in which you have a refrigerant 0:16:57.240 --> 0:17:00.160 running through a tube and it evaporates in parts of 0:17:00.160 --> 0:17:02.760 that system, it will absorb heat in that part, and 0:17:02.800 --> 0:17:04.840 if it condenses in another part of the system, it 0:17:04.840 --> 0:17:08.440 will release heat in that part. You can actually transfer 0:17:08.520 --> 0:17:12.520 heat from one part into the outside part. And that's 0:17:12.560 --> 0:17:18.000 how refrigerators and freezers work. Right. You've got essentially some piping, 0:17:18.160 --> 0:17:22.480 a tube, if you will, that runs through a freezer, 0:17:22.960 --> 0:17:27.359 and in this process, the refrigerant in that tube is 0:17:27.440 --> 0:17:30.960 boiling off into a gas and as such is absorbing 0:17:31.040 --> 0:17:34.439 heat through the entire pathway that's inside the freezer. It 0:17:34.480 --> 0:17:39.159 then passes through a condenser. The condenser's job is to 0:17:39.400 --> 0:17:44.800 pressurize this very now warm gas, and it becomes even 0:17:44.840 --> 0:17:48.119 hotter liquid because you've increased the pressure, you've increased the 0:17:48.160 --> 0:17:51.120 boiling point of this gas. It now has condensed into 0:17:51.160 --> 0:17:56.359 a liquid. The liquid you allow to pass through condenser 0:17:56.400 --> 0:18:00.720 coils and as it does so, it releases heat the 0:18:00.760 --> 0:18:05.919 external environment and then eventually it reaches an expansion valve. 0:18:06.160 --> 0:18:09.280 This valve only works in one direction. It allows the 0:18:09.480 --> 0:18:14.679 high pressure liquid to go through this expansion valve and 0:18:14.720 --> 0:18:18.280 then drop into an area of much lower pressure, at 0:18:18.280 --> 0:18:22.119 which point the liquid boils off and thus begins to 0:18:22.200 --> 0:18:25.199 absorb heat. So as it goes through the expansion valve, 0:18:25.640 --> 0:18:28.080 it's moving into the freezer again, right, that's where it's 0:18:28.080 --> 0:18:31.320 pulling the heat from the freezer into this boiled off 0:18:31.320 --> 0:18:34.760 refrigerant and it goes through the system again. So really 0:18:34.760 --> 0:18:37.200 you can think of the expansion valve and the condenser 0:18:37.560 --> 0:18:41.280 as creating two different sections of this system. In one 0:18:41.359 --> 0:18:46.200 section you have low pressure and that's where the refrigerant 0:18:46.200 --> 0:18:48.719 can absorb heat, and then the other section you have 0:18:48.960 --> 0:18:54.000 high pressure and that's where the refrigerant condenses and releases 0:18:54.040 --> 0:18:58.120 heat to the outside environment. So a lot of industrial 0:18:58.280 --> 0:19:02.080 modern ice cream machines use this method, and again it's 0:19:02.080 --> 0:19:04.760 pretty simple really when you get down to it. I mean, 0:19:04.840 --> 0:19:07.840 you do have a motor that you have to deal 0:19:07.880 --> 0:19:11.640 with with the condenser, right like, that's an actual motorized 0:19:11.880 --> 0:19:15.840 part of the system. But otherwise you're using valves and 0:19:15.920 --> 0:19:19.720 pipes to just take advantage of physics in order to 0:19:20.320 --> 0:19:24.240 make a section very cold and to transfer that heat 0:19:24.240 --> 0:19:27.800 to the outside again, same way the air conditioners work. 0:19:28.280 --> 0:19:33.120 So pretty cool anyway, This is just one component obviously, 0:19:33.200 --> 0:19:35.680 of ice cream machines, even the one we talked about 0:19:35.680 --> 0:19:39.160 earlier with the ice and rock salt. Cooling it down 0:19:39.280 --> 0:19:40.920 is just one part of it. Another part of it 0:19:40.960 --> 0:19:45.520 is churning the ice cream. When you churn ice cream, 0:19:45.560 --> 0:19:51.240 you're introducing air into the mixture, into the fat, the milk, 0:19:51.400 --> 0:19:53.680 and the sugar and whatever else may be in it. 0:19:54.400 --> 0:19:57.800 This makes the ice cream fluffier. You wouldn't want just 0:19:57.840 --> 0:20:00.520 a solid block of sweetened cream. It would be very 0:20:00.560 --> 0:20:03.560 difficult to eat. You want it to have that consistency 0:20:03.560 --> 0:20:07.720 where it's kind of cloudlike and fluffy. Churning more and 0:20:07.760 --> 0:20:11.879 more air into this mixture will make it softer and softer. 0:20:12.680 --> 0:20:15.159 So if you are able to do this enough, you 0:20:15.200 --> 0:20:17.600 can make it soft enough so that you can treat 0:20:17.600 --> 0:20:20.600 the ice cream as if it's a semi liquid. You know, 0:20:20.640 --> 0:20:22.680 you can use you know, pumps and stuff, or even 0:20:22.760 --> 0:20:27.199 just gravity to allow it to flow through pipes or 0:20:27.320 --> 0:20:31.199 a valve or a spigot as it were. Now this 0:20:31.240 --> 0:20:35.240 brings us back to mister Charles Taylor back in nineteen 0:20:35.320 --> 0:20:39.000 twenty six, so he files his patent in December nineteen 0:20:39.040 --> 0:20:41.920 twenty six. The patent is still available for you to read. 0:20:42.320 --> 0:20:43.879 In fact, I did read it. I looked at the 0:20:43.920 --> 0:20:47.760 images and everything. It's pretty cool. No pun intended it 0:20:47.880 --> 0:20:51.360 used a compressor and use condenser coils and that kind 0:20:51.359 --> 0:20:53.880 of thing. It did rely on a salted liquid as 0:20:53.920 --> 0:20:57.720 the refrigerant and It used an electric motor to provide 0:20:57.760 --> 0:21:01.040 the churning motion in the freezing chambers, so it didn't 0:21:01.119 --> 0:21:06.000 require a human being to use their actual physical labor 0:21:06.200 --> 0:21:09.440 to churn the ice cream. And his ice cream chamber 0:21:09.480 --> 0:21:14.040 also featured a spout where you could draw the soft 0:21:14.119 --> 0:21:17.960 ice cream out by opening up a valve. There's some 0:21:18.119 --> 0:21:21.840 disagreement in the world of ice cream, which I did 0:21:21.840 --> 0:21:25.400 not realize was a thing, but it is. But there's 0:21:25.400 --> 0:21:29.880 some disagreement as to whether Chuck Taylor, Charlie Taylor, Charles 0:21:29.880 --> 0:21:33.520 I guess I should say, invented soft serve ice cream actually, 0:21:33.720 --> 0:21:37.640 or if someone else did, Whether he invented soft serve 0:21:37.680 --> 0:21:41.040 ice cream or he just made a machine that was 0:21:41.080 --> 0:21:44.160 really good at making it. The end of the line 0:21:44.280 --> 0:21:48.840 is that his device worked, and that's when he moved 0:21:48.880 --> 0:21:53.640 out of becoming an ice cream businessman to a ice 0:21:53.680 --> 0:21:58.000 cream maker businessman. He made the equipment that other ice 0:21:58.040 --> 0:22:02.119 cream shops would end up using, and thus was born 0:22:02.400 --> 0:22:06.639 the Taylor Freezer Company. Okay, we're gonna now flash forward 0:22:06.960 --> 0:22:10.960 by three decades. Now. We're up to nineteen fifty six. 0:22:11.800 --> 0:22:14.440 That was the year when the head of the McDonald's Corporation, 0:22:14.520 --> 0:22:17.800 a guy named Ray Croc, whom you can learn about 0:22:17.840 --> 0:22:22.320 in Other Stuff podcasts. I think Stuff you Should Know 0:22:22.359 --> 0:22:25.240 has done an episode on him. I'm sure like there's 0:22:25.240 --> 0:22:27.880 been stuff I Know. Ben Bullen must have talked about 0:22:27.920 --> 0:22:29.800 Ray Croc at least once or twice in some of 0:22:29.840 --> 0:22:33.919 his shows. Anyway, Raycroc made a deal with the Taylor 0:22:33.960 --> 0:22:38.200 Freezer Company to buy Taylor machines so that his restaurants 0:22:38.240 --> 0:22:41.040 could make milkshakes and that kind of thing, and this 0:22:41.160 --> 0:22:45.959 became a long standing partnership between McDonald's and Taylor. That 0:22:46.000 --> 0:22:49.800 partnership continues to this very day. Now. A few years back, 0:22:50.280 --> 0:22:55.040 McDonald's did sign a contract with another ice cream machine 0:22:55.560 --> 0:23:01.760 company called Carpigiani. So technically franchises have two options when 0:23:01.760 --> 0:23:04.639 it comes to buying an ice cream machine for their store, 0:23:04.680 --> 0:23:06.120 but they have to buy it from one of those 0:23:06.160 --> 0:23:09.080 two vendors because of this contract. Like you, as a 0:23:09.080 --> 0:23:11.680 franchise owner, you do own the store, but you still 0:23:11.720 --> 0:23:16.280 have obligations to the corporate entity of McDonald's and one 0:23:16.320 --> 0:23:19.399 of those is you've got to work with McDonald's suppliers, 0:23:19.960 --> 0:23:23.000 and that includes the suppliers for their equipment. You can't 0:23:23.000 --> 0:23:27.000 go outside the restaurant's family to do that kind of stuff. 0:23:28.000 --> 0:23:31.719 But this still raises a question. Here are these tailor 0:23:32.560 --> 0:23:35.400 you know, freezer machines, these ice cream machines that can 0:23:35.400 --> 0:23:38.720 make all sorts of stuff when they're working, But why 0:23:38.800 --> 0:23:42.080 are they so frequently out of order? Right? Like, this 0:23:42.119 --> 0:23:44.600 is a company that traces its history back to nineteen 0:23:44.640 --> 0:23:48.959 twenty six, What is the problem that causes essentially a 0:23:49.000 --> 0:23:52.240 third of all of the McDonald's franchises in the United 0:23:52.280 --> 0:23:55.040 States to list that their ice cream machine is currently 0:23:55.400 --> 0:23:58.880 you know, off the menu as it were. Why are 0:23:58.920 --> 0:24:03.320 they not working? Well? This comes down to a few 0:24:03.520 --> 0:24:08.359 key factors. One is that proper operation of the tailor 0:24:08.440 --> 0:24:13.119