How To Make A Homemade Egg Candler Using Common Household Materials

A step-by-step guide to making your own egg candler
By BYC Support · Jan 10, 2012 · Updated May 1, 2012 · ·
  1. BYC Support
    Candling Eggs

    Found an old can light in the garage. I bought a flourescent bulb for it, since they don't make much heat.​

    Cut a hole in cardboard so the eggs would set slightly in it. I made two of these, one for the smaller bantam eggs.​

    Here it is with an egg on it.​

    Here it is with an egg on it -- lit up!​

    How to candle

    To candle, darken the room. Eggs can be out of the incubator (or away from a broody hen) for up to 20-30 minutes before starting to cool down inside, so don't rush. You can GENTLY roll the egg on the candler to get the best view.

    Out of the 14 eggs in this batch, we removed nine by day 14 that were obviously not developing. There is a chance that a non-developing egg will explode in the 'bator, and that is messy and STINKY. It hasn't happened to me yet, though.

    I wouldn't candle after day 16 or 17. The eggs are mostly chick (black mass) and air sac by then anyway, and they should be left alone for the last few days before hatching (no turning from day 18-hatch).

    Pics from day 8 candling

    (click any pic to see a larger version)

    Store-bought non-fertile egg for comparison​

    Undefined, hard to tell if there's a chick developing​

    Spots like this may indicate bacterial contamination​

    Nice air sac developing,
    a good sign
    Watch this one hatch

    Nothing going on here!​

    This one had a faint ring, which is a sign of bacterial growth​

    This looks undefined, but ended up hatching out fine​

    Well-formed baby inside!​

    Another good one​

    Good one​

    Same one, slightly different angle​

    Good one​

    Something in there, for sure​

    You may want to visit our homemade incubators section or ask questions about incubating your eggs in our Incubating & Hatching Eggs Forum Section.

    Also see here for more candling pics: Candling Pics Progression Through Incubation Of Chicken Eggs

    Share This Article

Recent User Reviews

  1. N F C
    "Homemade Candler"
    4/5, 4 out of 5, reviewed Mar 16, 2019
    A simple money-saving option.
  2. Anonymous
    "Nice how to article."
    4/5, 4 out of 5, reviewed Aug 9, 2018
    Good info & easy read.
  3. ronott1
    "Great Pictures"
    4/5, 4 out of 5, reviewed Jul 26, 2018
    Nice introduction to candling hatching eggs


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  1. Better Than Rubies
    Cool! Very creative idea. :D All I do is go in a dark room (usually the hallway closet), and hold the egg while shining a bright flashlight against it, and I personally feel like that works fine! :)
  2. Kessel23
    Cool, I just use my phone though.
      livenlaughnlove101 and Table4Six like this.
  3. ChikenChik
    I use a very bright led flashlight with a painters tape rim around the top to make a better fit with the egg. Works pretty well!
      EggSighted4Life likes this.
  4. 007Sean
    The pic of the egg with spotting, is not bacterial contamination. It is a very porous egg. Varying degrees of calcium having been layed down as it traveled through the pouch shell gland. The Adenovirus is responsible for this type egg. There is no effect on fertility or hatchibility of these type eggs.
      EggSighted4Life likes this.
  5. Debbi H
    Is it possible to candle a just-laid egg to see if it has the little blood spot in it signifying that it's fertile? I'd like to leave my broody hens with those eggs if I knew that they were actually fertile. I have 26 hens and 2 roosters (both smaller than my hens), but only a small percentage of the eggs are fertile when I crack them open for breakfast! Obviously, I don't want to leave eggs out there too long if they aren't even fertile.
    Can you tell if a freshly laid egg is fertile? Or would you have to wait a certain amount of days first?
    1. EggSighted4Life
      You cannot tell fertility by candling that early. If you can see a meat spot or blood spot on day 1, then that's exactly what it is... not embryo development. You can always candle the eggs under the broody around day 7 or earlier depending on your experience and egg color, and remove any non developers. I feed them back to my chickens and dogs. ;-)
  6. EggSighted4Life
  7. jafo
    going to check em tomorrow, day 8,,,,,,,,fingers crossed !
  8. Bducky
    Thanks for the chart!! I love the idea, but we are using our can light for the incubator i made. The chart is super helpful!
  9. babybuttonquail
  10. MyFrancesca
  11. chickenbusiness
    Just love it! It is priceless.
  12. TweetyNPetey
    But before i got the OvaScope, I was using this method, and it worked great!!
  13. TweetyNPetey
    I have a Brinsea OvaScope, and it works AMAZINGLY!!!! You can see so clear, it's almost as if you were looking right inside the egg!
  14. Coffeemama7
    Thank you for the wonderful pictures! My kids are now anxious to start candling all our eggs, even those in the fridge...this aught to be priceless!
  15. zara
    we also love this idea thanks
  16. wayne813
    just candled my eggs useing a soda can and lamp piece their doing real well thanks it works great
  17. gander111
    1 out of three so far looks like life!
  18. gander111
    I've got 12 eggs under my broody is day about to candle some..we'll see soon!
  19. MommysHomestead
    I candled 163 eggs last night and 1 is perfect, 37 of them are maybes and the rest are either bacteria spotted/ringed or infertile (mostly infertile). Turns out our hens had bottoms that were too fluffy and the roosters, well they just weren't 'making the right connection'. So all the girls got a trim and we are hoping the next batch has better results.
  20. Traci Jo
    Very helpful, I got off on the wrong foot with the first batch and hope to redeem myself on this new batch coming. Ten more days to candle...I'm excited!!!!!!
  21. wiggans6
    Yes rosenblat I want to know how to check for heartbeat too!
  22. Kellence
    a good egg candler is an iphone torch works great :)
      Nerry likes this.
  23. pioneerspirit
    good info. Last year I turned eggs right until they hatched....that's probably why I didn't get good results. Three hatches of 18 eggs...results: 2 hatched from 1st bunch, 6 from 2nd, 3 from third. thats really poor results, but then again I didn't candle them...which very well add to my poor results. I now got 17 at 9 days....need to check them. thanks for info. Cheers!!
  24. GreenGirlGrammy
    To rosenblat, how do you take an eggs heart beat?
  25. GreenGirlGrammy
    I have a broody hen that sat on 8 eggs for a week before I realized the bottom of her nest was open wire, exposed to very cool nights. In fact what made me think it may be a problem was that she got off the nest to eat, and they felt cool to me. I then put a styrofoam bottom in the nest, returned the straw and eggs. Now they are always warm, but I don't know if they are ruined. This is about the 18th day she has been on the nest. Now I have discovered her sister has been laying extra eggs in the nest. ARRRRHH...Can you tell I'm new at this?
  26. Chickarella
    Fantastic pics. This is where I have a hard time determining if it's a good or bad egg. Thanks.
  27. mommyof2kings85
    How do you know they are fertile, what dose it look like when you candel them when they are first layed?
  28. countrygirl5
    Thank you for this, my girls just had a ton of fun seeing a baby chick inside that egg! My broody is on day 5, and I was going to candle on day 7, but will patiently wait till day 14 to candle! Can't wait!!
  29. slink1211
    Thank you for this, what a great idea. We are having alot of fun candeling!
  30. Henpencker
    I love the idea of the bathroom cup and maglite thank you!
  31. rosenblat
    one of the eggs that appeared empty has a steady heartbeat
  32. rosenblat
    just candled my eggs using a bathroom cup and a maglite- very happy with the results
  33. ALRwild
    Great info! Thanks!

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