How to Candle Eggs
There are two different ways to effectively candle eggs. One pertains to shipped eggs with air cell damage and the other to non-shipped eggs.
Shipped Eggs:
Always keep the eggs air cell end up. It's best to leave them in an egg carton if you can. Put the light source on the air cell, not the bottom end or you will be able to see very little. Do not turn or rotate the egg, move the flashlight around it. This goes for other candler types too, even the stand candlers like the Brinsea OvaView. Flip the candler, not the egg. Don't jiggle or slosh the egg, that can kill the embryo, with the risk increasing if the membranes and interior have been severely damaged from shipping.
Image set one: how to hold the flashlight/other light source to candle eggs in a tray, e.g shipped eggs.
Non-Shipped Eggs:
Hold the egg at a slight angle, large end to the light source. Make sure your fingers don’t block the light and turn the egg slowly until either you see something or you’re certain there’s nothing to see. Again, be careful with the egg, but you can move it around much more than you could with a damaged one.
Image set two: how to hold the flashlight/other light source to candle eggs that can be rotated. The dotted line in the second image is showing where the air cell is.
When Not to Candle
Text credit goes to @MyPetChicken .
Egg candling can be a most addictive experience. Years ago, when I first started home incubation, egg candling would begin on the third day, and then happened again nearly every day thereafter until lockdown. I couldn’t get enough. Secluded in a dark room with a very strong flashlight, I would imagine my pile of eggs developing and hatching into the most beautiful flock that would ever grace my part of the county. Witnessing the embryo jump and move through the shell during egg candling was almost as exciting as watching my own baby on the ultrasound machine when I was pregnant. My imagination would not cease until the babies finally hatched and were moved into their brooder… where yet another addiction would take over—chick watching—but that’s another story. THIS story is about the problems that arose for me when egg candling was done too often.
Here are five reasons why egg candling too often has caused problems for me:
1. I discarded viable eggs.
I’ve learned that there is really no reason for me to candle an egg prior to the 10th day. If egg candling happens any sooner than that, I might toss an egg that is growing just fine. If you’ve ever had that sickening feeling in the pit of your stomach after opening a “cull” egg just to find a beautiful little chick growing, then you’ll know where I’m coming from. I also candle a bunch of dark-shelled eggs. When egg candling it is wayyyy easy to miss a growing baby behind those mahogany shells. WHEN IN DOUBT, leave it in the ‘bator!
2. I detached fragile air cells.
Shipped eggs bring their own set of rules. Thousands of dollars and many eggs later, I’ve learned a few things… one of which is that I have far better results if egg candling doesn’t happen right after they’ve been taken out of the box and unwrapped.
Now I simply give them a good visual inspection and allow them to rest. Resting means allowing the eggs to sit in the incubator for a few days, big end up, without the egg turner on. When egg candling happened too early, the extra handling, no matter how gentle I tried to be, often disturbed the fragile air cell. Now I just leave the darn things alone! You may think think that’s crazy talk, because conventional wisdom suggests egg candling right away to make sure there are no hairline cracks in the shells that can’t be seen by the naked eye. All I can say is that leaving them alone rather than egg candling that early has increased my shipped egg hatch rate by quite a bit.
3. I contaminated my eggs.
It is always imperative to only handle your hatching eggs with very clean hands. Over-handling, e.g. over-candling, will increase the potential of an egg getting contaminated from dirty hands, a sneeze or anything else! Contaminated egg shells create dead chicks or an egg that could explode in the incubator! Which brings me to this: Even if you smell a bad egg, it is not necessary to candle. VERY carefully put each egg to your nose and take a whiff. You will smell a bad egg quite distinctly, and you can remove it from your hatch without having to candle.
4. I dropped fertile eggs.
It is always a sad day when I drop an egg, even if it’s just headed for the frying pan. Imagine how much more tragic it is when the egg is destined for hatching. But it gets worse: you can also drop and egg being candled onto the eggs below it! Talk about a dingbat moment, you should have seen me the day I decimated three eggs that were growing beautifully just because I dropped one during a sneeze (see Rule #3). I couldn’t have cried more if my dog died!
5. I lost heat and humidity in my incubator.
Back when I used a homemade and styrofoam incubator, it was always a very worrisome headache trying to keep the humidity and temperature just right. There were nights I would spend on the floor next to the eggs to try to regulate the heat properly in an uncooperative incubator that became unruly every time I had to open the lid to turn, much less candle. Adding an egg turner to your incubator, and candling less often, will reduce the number of times you’ll have to fight this battle. (Bonus tip: Adding a little aquatic tubing so you can easily fill the water reserves will alleviate another reason to open the lid as well.)
Those are the five reasons I’ve reduced my egg candling.
So when DO I candle? Only twice, once at 10 days and again at 18 days. I candle at 10 days to cull the clears and the obvious quitters, and I can also perform the “sniff test” to detect if any are bad or rotten. Then I candle again at 18 days to cull any other quitters or bad eggs I might detect prior to lockdown. The next time I handle the eggs is when nothing can be hurt: during clean up, after the babies have hatched.
Many people may disagree and candle more often, but I can only speak about what works for me. Now, I physically cringe when I read, “I’m on day three. I keep candling but I can’t tell if these eggs are fertile.” Yikes! Granted, that used to be me, but having hatched literally thousands of chicks at this point, I’m hoping that someone out there will read this post and learn from my egg candling mistakes so they can take advantage of my experience to improve their hatch rates!
End of text from MyPetChicken.
Candler Suggestions
PowerLux Egg Candler
Product No. EC116 36.95
Hand held candler w/ a long lasting LED light. Use on white or brown shelled eggs to candle general embryo development. Comes with two easy to change end pieces for large and small eggs. Cord length 8 ft. Looks like it works well. #237 #33879
Sally's Candler
1" foam pipe to LED light #1645
After hatching so many marans, I needed a good one! It's 3000 lumens. I researched to find the brightest I could get in the most handy as well as cheap! I have bought up to 1500 lums and couldn't see into dark blue eggs, now they look like I am candling a duck egg, very quick fast and done. Love it!
Well worth the money spent and the rechargeable batteries rock!
Flashlight
Mic Stand — eBay (link might break) and another source
Saris' Candler
Modified toilet paper tube attached to a flashlight #49
Chicknlove's Candler
Light sabre candler! #40823
Peachickie's Candler
APG 3000 Lumens Zoomable CREE XM-L Q5 LED Flashlight Torch Zoom Lamp Light - 3 Mode Adjustable Brightness Waterproof Design Torch Lighting for Hiking, Camping & Outdoor Activity (Black) Click Here
Click Here
PrizePete's Candler
Click Here #33920
Joey's Candler
Click Here
Fire370's Candler Suggestions
#39023
BYC910's Candler
#1
Alkaline Battery Recharger for AAA, AA, C and D size Batteries
About the Product
Click Here
S5's Candler
#43551
Flocktastic's Candler
#33
Mamahmendez's Candler
#3901
Stromberg's Candlers
Click Here
Cynthia's Candler
That tape is fine, gets a bit warm if I take a long time candling, say... 30 eggs. Never had a problem overheating though. Cynthia12
I just clip it on the bottom drawer when I want to candle.
Try more than one flashlight for dark eggs!
If you have a cell phone you can use a flashlight app to candle. It works quite well.
Fertility in Eggs
Always break open clears before passing a verdict on fertility rates, especially if the eggs are shipped. Early deaths are easily mistaken for clears when candled and sometimes they will be fertile but fail to start. Read the links below for more information on identifying early deaths, infertile eggs, and FND eggs.
Article One
Article Two
Assessing Fertility After Incubation? #686
Sharpies on Eggs? Sure!
It's a question nearly as old as the proverbial which came first: can you safely use sharpies on hatching eggs to mark air cells or identify breed? Some BYCers have decided to take this to the extreme and colour the entire egg with multiple colours of Sharpie. Results are quite strongly indicative that it has no effect on hatchability.
Kathy's Sharpie Eggs #57059
Lamancha's Sharpie Eggs #8782
ILOVEFRIZZLES' Sharpie Eggs #1
From #57461
Saddle Shaped and Rolling Air Cell Images
Saddle shaped air cells is the term for when one or both sides of the egg have a large dip in the air cell. A lot of times with saddle shaped cells the chick doesn't position correctly for hatching. Their feet can get stuck behind their head and "smoosh" the chick so it can't move. It can also force the yolk sack and everything else further north in the shell. Keep a close eye on these eggs and make sure to pencil mark air cell lines. They are very common in shipped eggs.
Saddled air cell in early dead SH
Saddled air cell in early dead SH
Saddled air cell in early dead SH
Rolling air cells are just what the name implies: bubbles of air that roll freely throughout the whole egg like a carpenter's level. Prognosis for these eggs is generally poor—often, they have scrambled interiors.
Eggs with Incomplete CAMs
Link to post in case images break #80783
CAM (chorio-allantoic membrane) issues are often caused by improper or no turning especially through days 1–12. This is when the chorion and allantois are developing and eventually fuse, forming the chorio-allantois.
Source http://extension.missouri.edu/publications/DisplayPub.aspx?P=G8353
Below are some normal candled eggs plus some normal hatch debris:
Photo credit goes to Scratch Cradle.
Development of a Chicken Egg Day by Day
Candling Pictures day-by-day Click HERE
Bubble in Egg that's not from Air Cell? #25651
Blood Rings #25422 #43578 #80777
DIS Eggs #80780
Candle of a Fresh Egg #80804
Frozen and Re-thawed Egg #40744
Seeing development 12 hours in? Yes, it's possible! #29561
Miscellaneous Neat Candles #32316
Coturnix Quail Candling Guide
Are my Air Cells the Correct Size? See Below.
Candling Images:
*Note—unless specified, all images are of chicken eggs*
For more poultry information and notes please CLICK HERE for the Complete Guide to Incubation, Poultry Raising, Care and much more!
There are two different ways to effectively candle eggs. One pertains to shipped eggs with air cell damage and the other to non-shipped eggs.
Shipped Eggs:
Always keep the eggs air cell end up. It's best to leave them in an egg carton if you can. Put the light source on the air cell, not the bottom end or you will be able to see very little. Do not turn or rotate the egg, move the flashlight around it. This goes for other candler types too, even the stand candlers like the Brinsea OvaView. Flip the candler, not the egg. Don't jiggle or slosh the egg, that can kill the embryo, with the risk increasing if the membranes and interior have been severely damaged from shipping.
Image set one: how to hold the flashlight/other light source to candle eggs in a tray, e.g shipped eggs.
Non-Shipped Eggs:
Hold the egg at a slight angle, large end to the light source. Make sure your fingers don’t block the light and turn the egg slowly until either you see something or you’re certain there’s nothing to see. Again, be careful with the egg, but you can move it around much more than you could with a damaged one.
Image set two: how to hold the flashlight/other light source to candle eggs that can be rotated. The dotted line in the second image is showing where the air cell is.
When Not to Candle
Text credit goes to @MyPetChicken .
Egg candling can be a most addictive experience. Years ago, when I first started home incubation, egg candling would begin on the third day, and then happened again nearly every day thereafter until lockdown. I couldn’t get enough. Secluded in a dark room with a very strong flashlight, I would imagine my pile of eggs developing and hatching into the most beautiful flock that would ever grace my part of the county. Witnessing the embryo jump and move through the shell during egg candling was almost as exciting as watching my own baby on the ultrasound machine when I was pregnant. My imagination would not cease until the babies finally hatched and were moved into their brooder… where yet another addiction would take over—chick watching—but that’s another story. THIS story is about the problems that arose for me when egg candling was done too often.
Here are five reasons why egg candling too often has caused problems for me:
1. I discarded viable eggs.
I’ve learned that there is really no reason for me to candle an egg prior to the 10th day. If egg candling happens any sooner than that, I might toss an egg that is growing just fine. If you’ve ever had that sickening feeling in the pit of your stomach after opening a “cull” egg just to find a beautiful little chick growing, then you’ll know where I’m coming from. I also candle a bunch of dark-shelled eggs. When egg candling it is wayyyy easy to miss a growing baby behind those mahogany shells. WHEN IN DOUBT, leave it in the ‘bator!
2. I detached fragile air cells.
Shipped eggs bring their own set of rules. Thousands of dollars and many eggs later, I’ve learned a few things… one of which is that I have far better results if egg candling doesn’t happen right after they’ve been taken out of the box and unwrapped.
Now I simply give them a good visual inspection and allow them to rest. Resting means allowing the eggs to sit in the incubator for a few days, big end up, without the egg turner on. When egg candling happened too early, the extra handling, no matter how gentle I tried to be, often disturbed the fragile air cell. Now I just leave the darn things alone! You may think think that’s crazy talk, because conventional wisdom suggests egg candling right away to make sure there are no hairline cracks in the shells that can’t be seen by the naked eye. All I can say is that leaving them alone rather than egg candling that early has increased my shipped egg hatch rate by quite a bit.
3. I contaminated my eggs.
It is always imperative to only handle your hatching eggs with very clean hands. Over-handling, e.g. over-candling, will increase the potential of an egg getting contaminated from dirty hands, a sneeze or anything else! Contaminated egg shells create dead chicks or an egg that could explode in the incubator! Which brings me to this: Even if you smell a bad egg, it is not necessary to candle. VERY carefully put each egg to your nose and take a whiff. You will smell a bad egg quite distinctly, and you can remove it from your hatch without having to candle.
4. I dropped fertile eggs.
It is always a sad day when I drop an egg, even if it’s just headed for the frying pan. Imagine how much more tragic it is when the egg is destined for hatching. But it gets worse: you can also drop and egg being candled onto the eggs below it! Talk about a dingbat moment, you should have seen me the day I decimated three eggs that were growing beautifully just because I dropped one during a sneeze (see Rule #3). I couldn’t have cried more if my dog died!
5. I lost heat and humidity in my incubator.
Back when I used a homemade and styrofoam incubator, it was always a very worrisome headache trying to keep the humidity and temperature just right. There were nights I would spend on the floor next to the eggs to try to regulate the heat properly in an uncooperative incubator that became unruly every time I had to open the lid to turn, much less candle. Adding an egg turner to your incubator, and candling less often, will reduce the number of times you’ll have to fight this battle. (Bonus tip: Adding a little aquatic tubing so you can easily fill the water reserves will alleviate another reason to open the lid as well.)
Those are the five reasons I’ve reduced my egg candling.
So when DO I candle? Only twice, once at 10 days and again at 18 days. I candle at 10 days to cull the clears and the obvious quitters, and I can also perform the “sniff test” to detect if any are bad or rotten. Then I candle again at 18 days to cull any other quitters or bad eggs I might detect prior to lockdown. The next time I handle the eggs is when nothing can be hurt: during clean up, after the babies have hatched.
Many people may disagree and candle more often, but I can only speak about what works for me. Now, I physically cringe when I read, “I’m on day three. I keep candling but I can’t tell if these eggs are fertile.” Yikes! Granted, that used to be me, but having hatched literally thousands of chicks at this point, I’m hoping that someone out there will read this post and learn from my egg candling mistakes so they can take advantage of my experience to improve their hatch rates!
End of text from MyPetChicken.
Candler Suggestions
PowerLux Egg Candler
Product No. EC116 36.95
Hand held candler w/ a long lasting LED light. Use on white or brown shelled eggs to candle general embryo development. Comes with two easy to change end pieces for large and small eggs. Cord length 8 ft. Looks like it works well. #237 #33879
Sally's Candler
1" foam pipe to LED light #1645
After hatching so many marans, I needed a good one! It's 3000 lumens. I researched to find the brightest I could get in the most handy as well as cheap! I have bought up to 1500 lums and couldn't see into dark blue eggs, now they look like I am candling a duck egg, very quick fast and done. Love it!
Well worth the money spent and the rechargeable batteries rock!
Flashlight
Mic Stand — eBay (link might break) and another source
Saris' Candler
Modified toilet paper tube attached to a flashlight #49
Chicknlove's Candler
Light sabre candler! #40823
Peachickie's Candler
APG 3000 Lumens Zoomable CREE XM-L Q5 LED Flashlight Torch Zoom Lamp Light - 3 Mode Adjustable Brightness Waterproof Design Torch Lighting for Hiking, Camping & Outdoor Activity (Black) Click Here
- Skid-proof, waterproofing design, "O" ring sealed.
- Super bright, blinding effect, adjustable focus range for different usage.
- Convex lens reflector; clip for convenience carry.
- Internal wiring applies the high efficient booster circuit, working voltage is wide and can utilize the batteries in the largest extent.
- Suitable for self safety, hunting, cycling, climbing, camping and outdoor activity etc.
Click Here
PrizePete's Candler
Click Here #33920
Joey's Candler
Click Here
Fire370's Candler Suggestions
#39023
BYC910's Candler
#1
Alkaline Battery Recharger for AAA, AA, C and D size Batteries
About the Product
- total of 4 charging stations
- 4 AAA or AA batteries, 2 C or D batteries or 2 AAA or AA and 1 C or D batteries at one time
- Help benefit the environment and save money on replacement batteries.
- Charges brands such as; Duracell, Eveready, Sanyo, Polaroid, Panasonic, and Rayovac
- With the cost of a typical alkaline battery 6 pack ranging in price from $4.99 to $8.99, this unit will pay for itself in just a few re-charges.
Click Here
S5's Candler
#43551
Flocktastic's Candler
#33
Mamahmendez's Candler
#3901
Stromberg's Candlers
Click Here
Cynthia's Candler
That tape is fine, gets a bit warm if I take a long time candling, say... 30 eggs. Never had a problem overheating though. Cynthia12
I just clip it on the bottom drawer when I want to candle.
Try more than one flashlight for dark eggs!
If you have a cell phone you can use a flashlight app to candle. It works quite well.
Fertility in Eggs
Always break open clears before passing a verdict on fertility rates, especially if the eggs are shipped. Early deaths are easily mistaken for clears when candled and sometimes they will be fertile but fail to start. Read the links below for more information on identifying early deaths, infertile eggs, and FND eggs.
Article One
Article Two
Assessing Fertility After Incubation? #686
Sharpies on Eggs? Sure!
It's a question nearly as old as the proverbial which came first: can you safely use sharpies on hatching eggs to mark air cells or identify breed? Some BYCers have decided to take this to the extreme and colour the entire egg with multiple colours of Sharpie. Results are quite strongly indicative that it has no effect on hatchability.
Kathy's Sharpie Eggs #57059
Lamancha's Sharpie Eggs #8782
ILOVEFRIZZLES' Sharpie Eggs #1
From #57461
Saddle Shaped and Rolling Air Cell Images
Saddle shaped air cells is the term for when one or both sides of the egg have a large dip in the air cell. A lot of times with saddle shaped cells the chick doesn't position correctly for hatching. Their feet can get stuck behind their head and "smoosh" the chick so it can't move. It can also force the yolk sack and everything else further north in the shell. Keep a close eye on these eggs and make sure to pencil mark air cell lines. They are very common in shipped eggs.
Saddled air cell in early dead SH
Saddled air cell in early dead SH
Saddled air cell in early dead SH
Rolling air cells are just what the name implies: bubbles of air that roll freely throughout the whole egg like a carpenter's level. Prognosis for these eggs is generally poor—often, they have scrambled interiors.
Eggs with Incomplete CAMs
Link to post in case images break #80783
CAM (chorio-allantoic membrane) issues are often caused by improper or no turning especially through days 1–12. This is when the chorion and allantois are developing and eventually fuse, forming the chorio-allantois.
Source http://extension.missouri.edu/publications/DisplayPub.aspx?P=G8353
Below are some normal candled eggs plus some normal hatch debris:
Photo credit goes to Scratch Cradle.
Development of a Chicken Egg Day by Day
Candling Pictures day-by-day Click HERE
Bubble in Egg that's not from Air Cell? #25651
Blood Rings #25422 #43578 #80777
DIS Eggs #80780
Candle of a Fresh Egg #80804
Frozen and Re-thawed Egg #40744
Seeing development 12 hours in? Yes, it's possible! #29561
Miscellaneous Neat Candles #32316
Coturnix Quail Candling Guide
Are my Air Cells the Correct Size? See Below.
Candling Images:
*Note—unless specified, all images are of chicken eggs*
- Day 2 #18794 #28110
- Day 3 #80805 Movement of Embryo Begins on Day Three, #37214
- Day 4 #66553 Day 4 guinea #29521 Day 4 duck #79818
- Day 5 #80806
- Day 6 #80807 Day 6 guinea #3276
- Day 7 #80808 Day 7 duck #80809
- Day 8 #100384
- Day 9
- Day 10 #80810 Day 10 duck #81978 #29069
- Day 11 #102057 Day 11 guinea #92803 Day 11 Call duck #1348
- Day 12 #80812 Day 12 duck #26271 Muscovy #29623
- Day 13 #1559
- Day 14 #80813 Day 14 duck #83584 #152947 Day 14 Call duck #1844
- Day 15 #3090 Day 15 duck #5303
- Day 16 #22134
- Day 17 #51445 #35739 Day 17 Muscovy #32422
- Day 18 Call duck #2696 Day 18 duck #84853 #32141
- Day 19
- Day 20
- Day 21 duck #85709
- Day 22
- Day 23
- Day 24 duck #87139
For more poultry information and notes please CLICK HERE for the Complete Guide to Incubation, Poultry Raising, Care and much more!
