# Juicing a watermelon **URL:** \ **Category:** Factual Questions\ **Created:** [August 20, 2019, 10:40pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971 "2019-08-20T22:40:45Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [August 20, 2019, 10:40pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/1 "2019-08-20T22:40:45Z")
Would it be possible to juice a watermelon without destroying the rind, either by shaking it vigorously or in a centrifuge? Let’s say you could put small holes in the rind to let air in if necessary, but the rind should remain relatively intact. Basically, could it be juiced in place? Apply whatever method and then pour out the juice? (I wish I had a direct line to Randall Munroe, because this seems right up his alley) RS ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [August 20, 2019, 10:50pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/2 "2019-08-20T22:50:08Z")
Yup, Mark Rober [did a video](https://www.youtube.com/watch?v=IJ-h0SO8EUI) on it a while ago. Basically, cut a small hole it, attached a semi straightened out hanger to a drill and scramble the insides. More of a smoothie than juice, but you could certainly filter it and pour the juice back in. PS, his videos are really, really good and fun to watch. Also, he was part of the team that built some of the Mars rovers. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 20, 2019, 11:19pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/3 "2019-08-20T23:19:50Z")
I’ll admit I’ve never done the experiment but it seems to me that any shaking or spinning that would be enough to liquify the inside of a watermelon would also destroy the structure of the rind. ---
**Author:** ![TokyoBayer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tokyobayer/32/13989_2.png) [@TokyoBayer](https://boards.straightdope.com/u/TokyoBayer)\ **Post date:** [August 20, 2019, 11:28pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/4 "2019-08-20T23:28:43Z")
> [@Little\_Nemo](#): > > I’ll admit I’ve never done the experiment but it seems to me that any shaking or spinning that would be enough to liquify the inside of a watermelon would also destroy the structure of the rind. I don’t think so. I think with experimenting it could be done. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [August 20, 2019, 11:31pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/5 "2019-08-20T23:31:04Z")
> [@Little\_Nemo](#): > > I’ll admit I’ve never done the experiment but it seems to me that any shaking or spinning that would be enough to liquify the inside of a watermelon would also destroy the structure of the rind. I don’t know about shaking or spinning, but the video I linked to works (I mean, it must, right?) and I’ve hallowed out more than my share of watermelons over the years. Scraping the insides with a spoon is pretty similar to scraping the inside of a pumpkin. You’re not going to accidentally go through it, it’s pretty tough. ---
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [August 20, 2019, 11:34pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/6 "2019-08-20T23:34:36Z")
> [@Joey\_P](#): > > Yup, Mark Rober [did a video](https://www.youtube.com/watch?v=IJ-h0SO8EUI) on it a while ago. Basically, cut a small hole it, attached a semi straightened out hanger to a drill and scramble the insides. More of a smoothie than juice, but you could certainly filter it and pour the juice back in. > > PS, his videos are really, really good and fun to watch. Also, he was part of the team that built some of the Mars rovers. That is super cool, but doesn’t really answer the question. My daughter, a food science major, says that’s basically just sticking an emulsifier into it. We’re wondering if you can liquefy it using force. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [August 20, 2019, 11:40pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/7 "2019-08-20T23:40:24Z")
> [@RitterSport](#): > > That is super cool, but doesn’t really answer the question. My daughter, a food science major, says that’s basically just sticking an emulsifier into it. We’re wondering if you can liquefy it using force. In that case, I’m going to guess no. Maybe something like a paint shaker and a really ripe melon, but without access to the flesh, I’m kinda doubting it. The insides don’t have a whole lot of weight to them, so if you shake the entire melon, the flesh won’t have enough inertia to slam into the sides each time you change directions. It would be like trying to shake an orange and hoping the juice would separate out. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 21, 2019, 12:06am UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/8 "2019-08-21T00:06:08Z")
> [@Joey\_P](#): > > I don’t know about shaking or spinning, but the video I linked to works (I mean, it must, right?) and I’ve hallowed out more than my share of watermelons over the years. Scraping the insides with a spoon is pretty similar to scraping the inside of a pumpkin. You’re not going to accidentally go through it, it’s pretty tough. I’m not arguing with the video. But I see a substantial difference between liquifying the interior by inserting a tool inside and doing so just by outside force. The tool is only going to be acting on the interior while the force will be acting equally on the whole melon. So I don’t think there’s a method where you can apply enough force to liquify the inside while having the rind intact. My speculation is that any motion which liquifies the interior 100% will also liquify the rind something like 90%. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 21, 2019, 12:17am UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/9 "2019-08-21T00:17:59Z")
The difficulty is that everything is close to the same density. If a watermelon’s just sitting there, the juice and the pulp are both pulled downwards by gravity, but there’s no room to go downwards, and so everything gets supported by buoyancy. Increase the gravity (as in a centrifuge), and that remains true. On the other hand, would you accept it if we drill one small hole in each end, and then subject the melon to enough gees to extrude the goop out one of the holes? This would be different from the drill method in that we would not be inserting any tube into the melon (aside from whatever we used to make the initial holes). That, I think, would probably be doable. ---
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [August 21, 2019, 1:29am UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/10 "2019-08-21T01:29:31Z")
> [@Chronos](#): > > The difficulty is that everything is close to the same density. If a watermelon’s just sitting there, the juice and the pulp are both pulled downwards by gravity, but there’s no room to go downwards, and so everything gets supported by buoyancy. Increase the gravity (as in a centrifuge), and that remains true. > > On the other hand, would you accept it if we drill one small hole in each end, and then subject the melon to enough gees to extrude the goop out one of the holes? This would be different from the drill method in that we would not be inserting any tube into the melon (aside from whatever we used to make the initial holes). That, I think, would probably be doable. We thought of that but it seems like a very different solution. You probably wouldn’t even need two holes, just one on the outward-facing side when it’s in a centrifuge. Seems like the consensus is that it can’t really be done inside the rind without destroying the watermelon. ---
**Author:** ![EdelweissPirate](https://avatars.discourse-cdn.com/v4/letter/e/8491ac/32.png) [@EdelweissPirate](https://boards.straightdope.com/u/EdelweissPirate)\ **Post date:** [August 21, 2019, 2:37am UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/11 "2019-08-21T02:37:54Z")
Aside from all the insides being nearly the same density, they’re also almost entirely made of water. Water is nearly incompressible, so shaking a watermelon is a lot like shaking a perfectly-full-and-sealed bottle of water: there’s almost no internal movement because the pressure is hydrostatic throughout. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [August 21, 2019, 3:58am UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/12 "2019-08-21T03:58:41Z")
Maybe [high-intensity focused ultrasound](https://en.wikipedia.org/wiki/High-intensity_focused_ultrasound) could do it. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [August 21, 2019, 12:14pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/13 "2019-08-21T12:14:36Z")
> [@scr4](#): > > Maybe [high-intensity focused ultrasound](https://en.wikipedia.org/wiki/High-intensity_focused_ultrasound) could do it. Exactly what I came here to suggest. Do it slow though if you don’t want to cook it. ---
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [August 21, 2019, 12:41pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/14 "2019-08-21T12:41:45Z")
Looks like pulses would be the way to go: > [@](#): > > However, pulsed waves may also be used if mechanical rather than thermal damage is desired. OK, who has access to one of those? I’ll bring the watermelon. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [August 21, 2019, 1:22pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/15 "2019-08-21T13:22:32Z")
Maybe yes. [![](https://img.youtube.com/vi/lC-gerbqgrQ/maxresdefault.jpg "Vegetables Turned Into Juice With Underwater Shockwaves") ](https://www.youtube.com/watch?v=lC-gerbqgrQ) ---
**Author:** ![Cheesesteak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cheesesteak/32/3694_2.png) [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)\ **Post date:** [August 21, 2019, 2:10pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/16 "2019-08-21T14:10:28Z")
Perhaps an upsized version of this [egg spinning](https://www.youtube.com/watch?v=aazP6zvJmiQ) method. The trick would be getting that first separation of the flesh from the rind. Once something starts sloshing around in there, rapidly spinning the rind different directions will get the insides to agitate and liquify. ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [August 21, 2019, 5:45pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/17 "2019-08-21T17:45:08Z")
> [@RitterSport](#): > > That is super cool, but doesn’t really answer the question. My daughter, a food science major, says that’s basically just sticking an \*\*emulsifier \*\*into it. We’re wondering if you can liquefy it using force. [Emulsifier](https://en.wikipedia.org/wiki/Emulsion#Emulsifiers) Is that really the word you intended to use? I don’t see how it applies. How about making a small hole and inserting a few tiny ball bearings, then shaking. I think that would probably work. (I haven’t tried it.) Would it count? ---
**Author:** ![RitterSport](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rittersport/32/6326_2.png) [@RitterSport](https://boards.straightdope.com/u/RitterSport)\ **Post date:** [August 21, 2019, 6:51pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/18 "2019-08-21T18:51:00Z")
> [@Peter\_Morris](#): > > [Emulsifier](https://en.wikipedia.org/wiki/Emulsion#Emulsifiers) > > Is that really the word you intended to use? I don’t see how it applies. > > How about making a small hole and inserting a few tiny ball bearings, then shaking. I think that would probably work. (I haven’t tried it.) Would it count? Apparently, these are also called emulsifiers (according to my food-science-major daughter): > **[Immersion blender](https://en.wikipedia.org/wiki/Immersion_blender)** > > An immersion blender, also known as a stick blender, mini blender, hand blender, or wand blender, is a kitchen blade grinder used to blend ingredients or purée food in the container in which they are being prepared. The immersion blender was invented in Switzerland by Roger Perrinjaquet \[de\], who patented the idea on March 6, 1950. He called the new appliance "bamix", a portmanteau of the French "battre et mixer" (beat and mix). Larger immersion blenders for commercial use are sometimes nickna An... I hadn’t used that usage before she said it, either. The ball bearing idea seems more like using an immersion blender or that clothes hanger, although in different form. We were trying to figure out if we could just use gravity or other forces, but as someone mentioned, the problem is two-fold – the density is pretty similar all the way through and water is not compressible. A thought occurs, though – what about a watermelon with seeds – could those be the ball bearings? Spin the watermelon, have the seeds go to the outside, rotate it 175 degrees, spin, rotate, spin. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [August 21, 2019, 7:53pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/19 "2019-08-21T19:53:44Z")
> [@Cheesesteak](#): > > Perhaps an upsized version of this [egg spinning](https://www.youtube.com/watch?v=aazP6zvJmiQ) method. > > The trick would be getting that first separation of the flesh from the rind. Once something starts sloshing around in there, rapidly spinning the rind different directions will get the insides to agitate and liquify. If the seeds are denser than the flesh, spinning could dislodge them toward the exterior of the melon, leaving some wiggle room for agitation to liquefy the rest. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [August 21, 2019, 11:35pm UTC](https://boards.straightdope.com/t/juicing-a-watermelon/838971/20 "2019-08-21T23:35:27Z")
> [@EdelweissPirate](#): > > Aside from all the insides being nearly the same density, they’re also almost entirely made of water. Water is nearly incompressible, so shaking a watermelon is a lot like shaking a perfectly-full-and-sealed bottle of water: there’s almost no internal movement because the pressure is hydrostatic throughout. PUt some water in a clear bottle, add a drop of food coloring, and spin the bottle. You’ll see that the water doesn’t move exactly with the bottle. Absolutely the water could tear through the relatively week flesh of a watermelon, as you’ll notice if you drop a watermelon. I think a paint shaker would do it fairly quicly, but I haven’t got a paint skaker to try it with. [Next page](https://boards.straightdope.com/t/juicing-a-watermelon/838971.md?page=2)