Boiled egg hardness tester

You can tell a hard-boiled egg
from a raw egg, just by giving it a spin,
because the fluid inside this sloshes around
and it really dampens it. But, when boiling eggs,
how do you tell if the eggs in here are done?
Now, you could just know how long the eggs take
to be done, and time it. But, that’s just too easy, and
you got to keep track of time. I could try to probe
the temperature inside the egg but that has
some unfortunate consequences. So, I’ve come up with this
contraption where you can help the eggs up, and then
give it a spin, back and forth. And, this egg is still, kind of
raw, so it really dampens. Whereas if I put the hard
boiled egg in here, that just bobbles back
and forth a lot. To make this one,
I just took some house wiring, stripped the insulation
and bent it into shape and bent a spring in here. But, the main problem
with this one is I can’t really
distinguish a soft boiled egg from a hard boiled egg.
Cause on a soft boiled egg, only the yolk is still liquid
and that just doesn’t provide enough dampening, so I
want to build one that oscillates faster, which
might be able to detect soft boiled.
So, I’m starting with a whisk that came apart, for some
stainless steel wire and I’ll use one of these
barrier strip connectors and a stiffer spring. So, either I need a tighter
grip on the egg, or I need a spring that’s
a bit looser. It’s really important that the
coils of the spring don’t touch each other, cause
that will cause dampening. So, I need to stretch this
spring a little bit. Over-stretch it, in fact, so that the coils don’t
touch each other. It’s a little bit better. I think this one’s about right. except I dropped my egg
a few times. So, these eggs have got
maybe 2 minutes of boiling on them.
They don’t oscillate. So, still a ways to go. So, now it’s been
about 4 minutes. And, it oscillates
a little bit better. But, still nothing compared
to the hard boiled egg. A 6 minute egg and that’s oscillating
pretty good. Still not as much as
the hard boiled egg. 7 minute egg. And, it’s oscillating. Let’s see No, the hard boiled egg is still
going a little bit stronger But, let’s cut one open. And, let’s see.
Well, the yolk is getting firm, I guess this
level of stiffness is still hard to detect.
I quite like soft boiled eggs. I think this egg is now
indistinguishable from a hard boiled egg
at least as far as my gadget is concerned. Well, that is mostly
hard boiled. If I let that sit on the counter
for just a few more minutes, that would
completely set hard.


  1. I just steam them. I know from previous experience how much water to put at what notch in the knob. When the water is evaporated, the egg is boiled. Hard or soft depending on the CC.

  2. Please get an egg cooker! You might use the time you win not having to speculate about the hardness of your eggs on publishing another video on woodworking 😉

  3. I'll be disappointed if your second version doesn't use an oscilloscope and … lets say an electron gun from an old CRT.

  4. its cool but somewhat pointless nowadays 😛

    but it is interesting to know how they figured this out so many years ago with the timing

  5. What a fantastic waste of time…cool project! BTW I'm addicted to hard boiled eggs, 14 minutes using the cold water method.

  6. When I first started watching this video I was thinking it was a downstep from the regular content. Then I saw the awesome contraption and was satisfied.

  7. Matthias, I've been addicted to your channel for over 2 years, you made me think that I liked woodworking & I started collecting tools & even machine parts & dreamt with a house that has a shed to convert into a workshop…
    But I've been liking your recent video just as much as the older ones, minus woodworking !!!
    Mouse traps, egg hardnometer, glass springs, baby calming contraptions…
    I've been mislead for 3 years… It's not the woodworking, it's what you do, your solutions & your way of thinking…
    Love your videos…
    Thank you for the time you put in them.

  8. You can get a lot more consistency if you put less water in, and let the steam cook the eggs. Put a lid on it, and the steam will keep a more consistent temperature, as the water usually drops down from a boil when you add the eggs initially. There are quite a few videos about this method, including ones from Alton Brown and America's Test Kitchen I believe.

  9. I didn't wade through all of the comments to see if anybody else noticed but I see the old VW toolkit pliers you used there. I have a bunch of them kicking around.

  10. Hello, i was wondering if you could make wooden spheres, just as an experiment. I have no use, just curious of you could.

  11. A great demonstation of detecting what really is in the egg at a certain time. Setting a timer cannot be compared to this.

  12. I know this video is mostly just for fun (and don't get me wrong, I love it), but would it be possible to develop a hardness tester that takes objective measurement of the egg's softness? Perhaps something with a needle that indicates yolk softness? The method in the video seems to require more finesse than simply timing the egg, not less.

    Also, that penultimate softboiled egg looks perfect to me!

  13. What? No Rockwell Hardness scale measurement, or patented Mathias jump-test to see if it's done? Still, very clever and entertaining.

  14. To hard boil eggs, normal people use a timer. Engineers use a dampening device. I quite relate to the second category too.

  15. foolproof hard boiled eggs.
    1. small pan, add eggs to pan
    2. add enough cold water to cover eggs by 1 inch
    3. cover pan, place on heat, bring to boil
    4. remove from heat, leave covered for 12 minutes.
    5. run eggs under cold water to stop cooking.

  16. You could try to build an egg-inside-the-shell scrambler – a machine that spins the egg very fast so you can get scrambled eggs (or an egg-shaped omelet) inside the shell.

  17. I would love t o be around when, after Matthias' death, this thing ends up in some thrift store and people are puzzling over what in the hell it was used for

  18. I just watched a guy make a slighshot out of his beard and now this. I think it's time to leave YouTube for a while and go outside.

  19. How would elevation/air pressure influence air resistance when u use that oscillator-thing?? When I boil my eggs at my mountain cabin I just add one more minute. Do u have to twist the oscillator a fraction harder or softer, at lets say 3000 ft??

  20. OK, next step can be: construct a circular dial and an arrow to go between the wire connection to the spring, so that the arrow can oscillate freely on the dial (maybe dial suspended from the handle and arrow connected at the same place as the screws for the wire). Afterwards a couple of hundreds, thousands (??) of boiled eggs put to the test and opened after certain periods of boiling and you can draw segments on the dial which indicate the degree to which the subjects are being boiled (hard /soft hard). 😉

  21. Hi Matthias, good to see your mind is still active as ever! Just a thought to improve your egg hardness tester…years ago while working at Stanley we had vibratory screw feeders with an angular scale…when the feed was just right you would record the number where the endline stopped…with this sort of scale you could read the hardness of the egg directly.

  22. huh. this is pretty cool. can't say I'd buy it if it was commercially available but it seems like a good weekend project.

  23. I just scoop it out, play hot potato with it 2 or three times, and toss it back in the water. You can feel the yolk slosh if its not done, and you level up your manly stats.

  24. +Matthias Wandel I love your videos, but this is the most ludicrously over-complicated nonsense that I have ever seen. Little tip from an egg boiling expert… USE AN EGG TIMER!!

  25. We never saw how well the brown egg was cooked!!!  Your results are completely invalid!!!  Also, can I get plans for the tester?  : )

  26. lol.not scientific. My high school physics teacher would have said equal mass will result in equal oscillation. did you weigh your raw eggs to the 5th decimal to see if they are of equal starting mass? For expected cooking time?different mass heats and cooks at different times(excluding the effects of altitude for simplicity sake) so a 7 minute egg is just an estimate, hence your still soft boiled egg even after 7 mins. Grandma's home economics101, learned age 10 in her kitchen. 1967. fun experiment! hope you seriously engineer the heck out of that one as the simplest gadgets that solve age old problems are the money makers; I'd buy one for sure!

  27. In case no one has mentioned it, I'm disappointed you didn't cut into the so called "hard boiled" testing egg. haha, but this was awesome

  28. Matthias: A whisk that fell apart
    English Translation: A whisk that I broke using it for something it wasn't designed to do

  29. THIS is why his kid is gonna have a great childhood! I love the complexity and the proofs for both yes and no. Science FTW.

  30. Place eggs in saucepan. Put in enough water to cover the bottom – NO MORE! Place lid on saucepan. Turn on power FULL. Start timing. When it's boiling like made (i.e. plenty of steam emitting) turn off power. Leave 6 mins min (small eggs) Up to 8 mins large eggs. Result; soft boiled egg. May take a bit of practice. Advantage is use less power (don't have to boil loads of water and keep it boiling) and save time.


  32. no es solamente que se pase de los 11 minutos. el drama es que luego de los 11 minutos. capa exterior de la Yema se va poniendo verde. eso verde. se va amargando. cuestión de gustos. a ver que opina MATTHIAS. amargo o no amargo ?

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