Specific gravity of citrus fruit. Why do my lemons float and my limes sink?

[Ladewig]

While making some white sangria for a party, I put some thin lemon and lime slices in a pitcher of white wine. The lemon slices floated and the lime slices sank. I am at a loss to understand why.

[SezMe]

The lemon slices had an average density less than that of water while the lime slices had an average density greater than water.

You're very welcome. :) :)

Nonsense aside, I would GUESS that the rind or pulp of the lemon contains more trapped air than the lime.

[Meffy]

Presence or absence of seeds maybe?

[Bob Klase]

While making some white sangria for a party, I put some thin lemon and lime slices in a pitcher of white wine. The lemon slices floated and the lime slices sank. I am at a loss to understand why.

I'd guess that either a given volume of lemon weighs more than the same volume of lime, but it could be there's something in lemon that disruptes the surface layer of water.

[Ladewig]

Presence or absence of seeds maybe?


Near as I can tell, everything is the same: no seeds, same thickness of slice, same amount of rind, same diameter.

[tkingdoll]

Lime flesh is much denser than lemon flesh, as a result it holds its juice better (anyone who regularly juices both will know this). Perhaps that is the cause.

As an aside, if you want to get more juice from a lime, warm it up in the microwave briefly and then firmly roll it along the worktop before slicing it lengthways and juicing it. It makes a huge difference.

[Meffy]

Your say-so convinces me. I don't juice regularly.

[Crossbow]

Anything less dense than water (wood, oil, ice cubes, lemon, etc.) will float in water.

Anything more dense than water (concrete, lead, limes, etc.) will sink in water.

[Meffy]

Anything less dense than water (wood, oil, ice cubes, lemon, etc.) will float in water.
I recommend an amendment: "Anything weighing less than the volume of water it displaces..." This allows for ships of iron and such.

[Dogdoctor]

In my mind I think the flesh portion should be about equal weight per volume as water but the rind will have air spaces in it that make it lighter than water. Perhaps the rind on the lemon is larger or less dense than the rind on the lime. I guess the flesh of a lemon might have more fiber or something else that might be lighter than water also.

[Meffy]

Time for someone who has a lime and a lemon to get out a sharp knife and do some experiments. (Please?)

[Thing]

This reminds me of a story I heard ages ago, that once upon a time King Charles II asked the assembled Fellows of the Royal Society to explain why it was that a boiled egg floated but a raw one sank. After they'd debated for a day and confessed that they couldn't explain it, he replied that the answer was simple, it doesn't.

But I've just googled this story to make sure I've got it right and found no reference to it whatsoever. Am I mixing it up with another story, or do I not know how to use google, or did I dream the whole thing?

[Dogdoctor]

There may be differences in individual limes that may make some float and others sink. I know when I harvest produce from my garden there are differences in the flotation of tomatoes due to degree of ripeness and perhaps some other criteria.

[Meffy]

@Thing: It's a lot like the story of Columbus standing an egg on its end on the equinox... or something... all very likely forkloric but what the hey.

[mumchup]

My first thought was that it's because lemons have rather thick rinds with a large layer of pith, whereas limes usually have very thin rinds and almost no pith. A quick experiment appears to verify it.
(For full disclosure I must point out that I used water instead of white wine.) The lemon slice did indeed float and the lime sunk to the bottom of the bowl. The inner flesh of both the lemon and the lime sank to the bottom also. However, I would describe the slice of rind/pith as "very bouyant". And at the end of the experiment, I thought how much nicer it would have ended if I had used wine.

[casebro]

A duck floats!

[Art Vandelay]

While making some white sangria for a party, I put some thin lemon and lime slices in a pitcher of white wine. The lemon slices floated and the lime slices sank. I am at a loss to understand why.

The lemon slices had an average density less than that of water while the lime slices had an average density greater than water.

All emphasis mine.

[Ladewig]

This reminds me of a story I heard ages ago, that once upon a time King Charles II asked the assembled Fellows of the Royal Society to explain why it was that a boiled egg floated but a raw one sank. After they'd debated for a day and confessed that they couldn't explain it, he replied that the answer was simple, it doesn't.

But I've just googled this story to make sure I've got it right and found no reference to it whatsoever. Am I mixing it up with another story, or do I not know how to use google, or did I dream the whole thing?

My high school physics class was [mumble] years ago, but I remember an experiment where we added salt to water until we could make the hard-boiled eggs separate from the raw eggs. Is my memory so bad that I am recalling things that never happened?

[Dogdoctor]

My high school physics class was [mumble] years ago, but I remember an experiment where we added salt to water until we could make the hard-boiled eggs separate from the raw eggs. Is my memory so bad that I am recalling things that never happened?
An easier way to separate them is to spin then on a smooth surface like a table or counter top then tap them with your finger. The hard boiled eggs will stop when you tap them but the raw eggs will continue to spin due to inertia from the fluid insides which doesn't stop when you tap it.

[SezMe]

All emphasis mine.
Way to go, Art. You really cut to the heart of the matter with that post. :rolleyes:

[The Don]

Time for someone who has a lime and a lemon to get out a sharp knife and do some experiments. (Please?)
Well I've been sitting here in the British Airways lounge in Cape Town making Gins and Tonicses with both lime and lemon.

I've run five cycles of the experiment and I'm compelled to say..........WHat was the question again ?

[Meffy]

Slipped my mind too. Something about Nick and Nora Charles? :-}

[SezMe]

That's it. Why does Nick sink like a lemon and Nora float like a cork.

[Meffy]

Because Nora is a big-picture type who deals in generalities and has the more flippant manner, while Nick affects (facetiously) a more grave persona and drills down to details. The combinaton gives Nick a high specific gravity.

P.S.: The above is probably not accurate but IMO it was worth it for the cheap joke.

[SezMe]

Well, in your opinion ...... :)

[Wowbagger]

Maybe the lemon slices were witches.

[tkingdoll]

Maybe the lemon slices were witches.

:D

[bjb]

Wine has a different specific gravity than water. It's a few percent more dense overall so it's possible that the lemons would have sunk in water. In my own experience, lemon slices sink in lemonade, even when there's a fair amount of sugar added. The limes on our lime tree aren't ready yet so I can't experiment with them right now.

[Bruce]

Your say-so convinces me. I don't juice regularly.

If you don't juice regularly, your flaps start to get that not-so-fresh feeling. :rolleyes:

[Meffy]

Don't make me get all Jim Carrey (from his In Living Color days) on ya.