World’s LARGEST JELLO POOL- Can you swim in Jello?

This is the world’s first ever actual pool of Jello! And while it may look simple, it’s actually a very difficult engineering challenge to pull off. As proof, if you Google “Jello Pool,” you will either find bad CGI, or a handful of videos of people who tried to do this, but it really didn’t work out. So today, we are going to answer possibly the longest standing question from my childhood: What would it be like to actually belly flop in a pool of Jello? But before we do that, I want to talk about what we actually had to go through for the past 6 months to pull this off. The idea of a Jello pool has been on my bucket list for over 4 years. In fact, when Kevin from The Backyard Scientist and I made the 25 million Orbeez pool, our first idea was to do a pool of Jello, but it’s really hard. Because if you’ve ever made Jello, you might recall you first have to boil water, then mix in the powder, and then you have to refrigerate it for it to actually get firm. And that’s easy enough to do for a small dish but how do you boil and then refrigerate an entire pool? This seemed like a very worthy engineering challenge. So year at Thanksgiving, my brother and I came up with a plan and then in the middle of winter, we started digging a hole in his backyard. Then over the course of 2 months we set up a bunch of small-scale experiments because we needed to answer questions like: How much gelatin powder does it actually take to get to the ideal firmness? And how hot, and then cold, does the mixture actually need to get for the Jello chemical reaction to take place so it will actually get firm From our experiments, we learned that the Jello always got firm as long as the mixture got hotter than 160° Fahrenheit. So we decided we could scale this up by using 6, 55 gallon drums with a custom propane burner underneath and a spigot we welded to the sides, but more on that later. So now we knew how we were going to heat it up but how do you refrigerate an entire pool? For that, we teamed up with Mother Nature and just picked the perfect location and time of year. We installed a thermometer and starting in January we tracked the temperature in his backyard every night. We needed refrigerator temperatures at night, but not freezer temperatures, because that would freeze the jello and our experiments showed that totally ruins it. And so after looking at our data, plus historical temperature plots, we knew we had about a 3-week sweet spot window towards the end of April to pull this off. Our goal is to have a Jello pool party in his backyard, that would make even Phineas and Ferb jealous. So the plan was to start 7 days before the party, and fill the pool with an average of 10 barrels every day. That would give each layer a chance to get exposed to the cold night air, to more efficiently get rid of the heat. And so with that, first thing Saturday, a full week before the party, [water splash] we got to work ♪ Faidherbe Square – ProleteR ♪ We didn’t want to waste actual food, so this was just water and gelatin powder and food coloring. But there’s no sugar. ♪ Faidherbe Square – ProleteR ♪ We intentionally placed our barrels much higher than the pool, so when we’re ready, we can use the potential energy to move the Jello from the barrels to the pool. We had to tackle about a thousand other issues that came up, that I won’t bore you with, but day by day, and layer by layer, the pool began to fill up. Because the Jello went in with so much heat energy, we needed to remove before it could get firm, in addition to using the cold night air, my brother’s neighbor, Nick, happened to have a spare swamp cooler, in his shop. So we kept that running over the top of the pool, pretty much the whole week. This gave us convection cooling, it’s the equivalent of rolling down a car window for the pool, or like, when you blow on the top of a hot cup of soup. This constantly replaces the evaporating layer of air right at the surface with fresh, cold air, that will suck out the heat more efficiently. And so, as we put in the final batch Friday night with ominous weather threatening to ruin the whole effort. At this point, we had done all we could. We were exhausted after a week and I wasn’t feeling super confident because my specialty is more of mechanical things and this project was more about chemistry and thermodynamics. And I didn’t want that lame “Jelly-Baff” stuff people trying to pass off as Jello. And so even if it didn’t last long in the Sun, I wanted to at least have the experience of seeing even a single belly flop on a smooth pool of actual Jello. If this was gonna be a total failure, it wouldn’t be from lack of effort. And so we woke up Saturday morning, with a forecast for a warm sunny day and we pulled off the tarp to find a pool filled with actual freaking Jello. ♪ Sappheiro – Falling ft. eSoreni ♪ By this point, word in the neighborhood had definitely spread around as to what we were up to. And my brother asked if some of their friend’s kids could have first dibs. And so with that, I’m happy to report this is what it looks like to belly flop in a pool of Jello. ♪ Sappheiro – Falling ft. eSoreni ♪ Not yet! (Wait, wait Adam) ♪ Pokemon in NYC ft. Missy – Andrew Applepie ♪ When I first got in myself, it was closer to the middle of the day and one of the things we discovered was that direct sunlight over time had the effect of undoing some of the solidness of the lower layers. (Laughter) When you go in it just feels-fills your nose and like ears. It’s a very surreal feeling I’m just being like. Its kinda hard to move but its just slimy and slippery It actually feels really cool We have some pool toys uhh… hidden underneath Got it! Wow! It’s unlike anything I mean it’s like swimming in snot. If that makes any sense? But like a good snot! To keep solid for even longer, if we were to do it again We might put in a heat exchanger pipe system beneath the surface sort of how like they freeze indoor ice-skating rinks. And maybe use a little sugar That’s disgusting! Now at this point you might be thinking
“Why would anyone spend their effort of 6 months of planning, and then a solid week of back-breaking effort just to make a stupid pool of Jello?” And to that I say, “Why do people go through the effort of climbing Mount Everest? Why did Neil Armstrong go through the effort of stepping on the moon? And why did Pam and Jim go through the effort of convincing Dwight, that Jim had always been Asian?” Dwight: “This is Jim.” Sometimes, you don’t do a thing because you should, but simply to prove that you can. Now that my curiosity was fully satiated and on my ongoing quest to be the favorite uncle, I told my nephews they can invite some of their friends over And my brother’s family, setup a neighborhood BBQ. And at this point, after a lot of hours of belly flops, and bowling balls, and direct sunlight, The Jello was pretty broken down But that didn’t stop us from setting up a Jello pool slip-and-slide ♪ Pata Pata – Matt Chene ♪ And I love their sense of adventure but it was a bit of an “Uncle Fail Moment” because apparently, none of them have ever used a slip-and-side ♪ Pata Pata – Matt Chene ♪ We didn’t actually put any sugar in here so it’s kinda disgusting so, we’ve got some real- (Ominous Music) This was a Bucket List video idea I’ve had for as long as I can remember and I wouldn’t have been able to pull it off if it wasn’t for the support of my friends at “NordVPN” As I’m sure you know by now, by using a “VPN”, you can search the web anonymously, you’re location stays private and your data is encrypted And for my friends in the EU you might have heard recently that article 13 passed. That means that a lot of the websites you love to use, will be forced to be far more restricted. I’m not saying you do this But hypothetically, if you’re using the VPN, You can virtually teleport and trick the internet to think you’re In any country you want (American Patriotic Song) And “NordVPN” is the best because they have thousands of servers in over 61 countries. Plus they have a 30 Day money-back guarantee on super remote chance you try it, and for some reason you’re not totally satisfied. To virtually teleport around the world or given today’s headlines, if you’re just ready to take you’re privacy more seriously, you can go to: Or use this link in the video description for 75% off they’re 3-Year plans which works out for less than 3 bucks a month. So it’s and if you use the code “MarkRober” in checkout, they’ll throw in an extra month for free. Thanks for watching! (Ending Title Music) (Draining Noises)


  • My bucket list is now one item shorter. This was a brutal amount of work but a worthy engineering challenge. MASSIVE thanks to my buddy Devin Super Tramp for filming this so don't get used to this high quality from me. He is a living legend.

  • First dibs they did no work for it workers get first dips they come in after

  • Bro you need to do a collab with Mr Beast

  • I really love the efforts u put in each video😍😍

  • SEE morgz

  • amazing finaly

  • Mr beast wants to know ur location

  • 6:13 with different music the atmosphere would be so much different.

  • 2:13

  • Woah

  • I love the flavour red

  • Nord VPN

  • The real question is can u run on it 🤔

  • Cool

  • Bucket list. More like pool list.

  • Sadly u can’t eat it cause there are kids dirty feet in their

  • What if it rained..?

  • Can't you eat it

  • Now I don’t like being British

  • Pool of chocolate

  • نعمه الله يخذك امك

  • You know I'm learning more here than in school
    Thank you 😊

  • The dinosaur part it was so awesome I just watch this video and I'm new and I just subscribed because that

  • You should have ask help from a chef so that he would have told you to cook the gelatin in a lot less water and then add cold water. It would have been a lot faster for heating and cooling…

  • OMG you saved my life of boredom!! Thanks!

  • Is nobody seriously asking how they cleaned this?

  • C R E E P E R?

  • Send the kids in first….. lmfao dude

  • Smart!!

  • wrong it was jake paul not the first one

  • You are so nice letting those kids go in first because I would have been like "nope, I get the first belly flop!" This looks awesome though haha

  • Any small Gachatubers want to support each other

  • ❤❤ house

  • this guy is so smart, get him into harvard

  • Lol

  • Mark rivers hot nerd lol

  • woah a jelly….. XD

  • Not only is he the best uncle but the best neighbor.

  • Who was the lucky person to clean that mess up?

  • Lovely ! Great music , great kids . You gave us the right vibes.

  • dying laughing

  • Who liked the dino that in the end?💔😂

  • 4:41 my thighs when I run

  • You should be on yes theory

  • Why did he keep his hat on ?????

  • You guys clearly have not watch
    "Cloudy with a chance of Meatballs"

  • I wanna hear the noise of the belly flop XD

  • Sugar would have been horrible anyway bc of the ants…

  • 0:16

  • This looks awesome! I’m so glad you finished it and actually knew how to do it. That must be fun! Also I subscribed.

  • “But like a GOOD Snot!”- Mark Rober

  • why does this keep coming up in my recommendation all the time

  • Great content:)

  • 1 like=1 respect

  • 0:54 that is easy , just move to ireland

  • Wow! You have a new subscriber! Absolutely amazing!

  • حرم هذي نعمت الله
    ميصلح يولد😠

  • Oh snap it's like what Nero went through to shift between areas to get to urizen lmao

  • That dinosaur at the end looked like it might have been the dinosaur from Tik Tok

  • Rezendeevil vai querer copiar HAJAHJAHHAHASHSSJHSD

  • Come on don't eat it kids but their bodies in it

  • Is it sticky?sorry I'm dum .-.

  • 9:53 ooooh i got that jurassic park sceeeeene thooooough 😂😂😂

  • Imagine being in the same silence class as mark

  • Wow😯😯😐😐

  • You forgot to walk over it

  • Mana nih orang Indonesia

  • They are basically swimming in animal guts

  • Its really awsome! I am really amazed!

  • Easy answer:

  • Mark I See Your Profile Picture Has Changed Can You Tell Me Why?

  • Salute for your hardwotk

  • I like how you guys didn't wast food


  • if u get stuck gl getting out

  • Did Mr beast just show up at the end of the video????🤔😁🤣

  • It's looks like tomato juice xD (when it melted)

  • That's amazing, but I can't stop thinking about all the bacteria that started forming in the gelatin all those days haha

  • God dammit I wish u were my uncle

  • the people that disliked are literally the definition of haters, this was amazing

  • 😃

  • That's so dope

  • You have a new sub

  • where is this neighborhood, unreal views

  • Do not like this comment

  • I seriously love you.

  • I wanna see if it'll hold you on top

  • 29999 dislikes, im 30000

  • People who dislike the video were too jealous

  • 5:02 that's cute😂

  • Mark is best uncle and best channel on YouTube

  • Was that shgurr

  • 8:42 LOVE THE SONG

  • A love it❤

  • imagine being this smart

  • Run across it


    Show leo

  • .O. i Wanna try that to…😎😱

  • Oh boy howd yall clean that up

  • Best video ever. Your videos are so intresting, thats why i love your videos

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