Egg Quality/Egg Washing

A Whole Chapter on Egg Quality

Read the USDA Egg Grading Manual

Frequently Asked Questions

1. I'm getting shell-less eggs. What do I do?

Eggshells require a lot of calcium. I recommend that every flock be provided with a feeder full of ground oystershells (available at any feed store). Do this even if you're feeding a balanced laying diet.  This allows hens to eat something other than the layer diet (such as bugs or grain), and still get the calcium they need. Hens have an accurate calcium appetite.

Feed-grade limestone also works, but in single-sack quantities the price difference isn't enough to worry about, and the hens prefer oystershell.
 

2. How do I prevent dirty eggs?

Hens who sleep and poop in the nest boxes. Hens who stay in the nest box at night are probably broody.  They should be kept in a broody coop (a cage with a wire floor) for three or four days.  A broody coop is so unlike a nest that it tends to cure them of their desire to sit on the nest with a clutch of eggs. Give them food and water or they'll go into a molt.

Hens who enter the nests with muddy feet. This is especially troublesome for hens with outdoor access.  If there's a broad stretch of litter (straw or wood shavings) on the floor between the henhouse door and the nest boxes, their feet will be less muddy. Also, if you arrange it so they have to walk across a shallow tray filled with powdered gypsum, powdered limestone (not hydrated lime or quicklime -- these are caustic!) or diatomaceous earth before entering the nest boxes, their feet will get coated with powder and won't leave marks on the eggs. Replacing the perches on the nest boxes with trays about four inches wide will work.

Broken Eggs. Nests with insufficient nest litter or with too many hens jammed in at once will have broken eggs, which are not only lost themselves, but add a messy, hard-to-clean coating on other eggs.  I think that nests that are unusually wide and have unusually deep litter work very well.  I removed half of the partitions from a pair of 8' nest boxes, leaving them with holes two feet wide instead of one foot wide, and this worked very well.  If the front boards on nest boxes are 6-8" high instead of the traditional 4" high, you can pile in a lot more litter.  If you use relatively heavy litter such as straw or wood chips, the hens don't scratch it all out of the box as quickly as wood shavings.

Traffic. Every time a hen enters the nest box or moves around while inside, there's a chance of an egg breaking.  Darkening the nests makes the hens less active. Turning the nest boxes around to face the wall or darkening the front with flaps of plastic tarp work very well. Using community nests or tunnel nests also works very well.
 

3. How do I wash dirty eggs?

Dry Cleaning. Washing eggs in water is a lot more complicated than dry cleaning with abrasives, so we'll talk about abrasives first.  You can clean up lightly soiled eggs with various abrasives. Sanding sponges from 3M and others are good, and can be found in any hardware store. Loofas are also good. Some people use sandpaper or steel wool, but these aren't as good as the first two.

Basically, you rub the egg until it's clean, or you give up, or it breaks in your hand. This happens more often than you'd think, because dirty eggs are often cracked as well.

Dry cleaning doesn't work very well to clean up eggs that have been smeared with the white or yolk of broken eggs in the nest.

Whatever you use to clean the eggs, it's best to wash and sanitize it from time to time.  Clean loofas or sanding sponges in soap and water, sanitize them in water with a little bit of bleach, then allow to dry.

These methods of cleaning are very slow and tedious. They are suitable for small flocks, but when you have significant numbers of eggs to sell, the labor involved in cleaning the dirty ones can become a big barrier to success and satisfaction. If you want to have a small commercial flock on your farm, you will almost certainly want to look into wet cleaning.

Wet cleaning is more complicated. The basic issue is that dirty eggs are covered with bacteria, which have trouble getting through the shell so long as it's dry. As soon as the shell is wet, they pass through the shell more easily. Also, if you cool the egg, the contents shrink a little, causing a partial vacuum inside that tends to suck foreign matter into the egg.

The upshot is that you should always wash eggs in water that's warmer than the egg is, and you should sanitize the eggshells to kill any bacteria on the shell.

Egg washing is a mature technology. The issues have been understood since the Thirties. However, early egg-washing machinery ran afoul of human nature. The old immersion-style washers worked superbly when run according to the instructions, especially if the water was replaced between each basket of eggs. But human nature is such that people can't resist running "just one more basket" through the washer. Sanitizers are ineffective when used in dirty water, and eggs washed in dirty water spoil quickly.

This sort of thing has given egg-washing a bad reputation, even though sanitary egg washers that don't have any of the problems of the old immersion washers have been around for over forty years, and proper egg-washing technique has been well-known for over sixty years. Wet cleaning is actually illegal in some countries, though not in the U.S.

The USDA does not allow immersion washers for eggs under their inspection. Many states repeat the USDA rules verbatim. Others, such as Oregon, are more forgiving. In any event, you don't have to use immersion washers. The method I give below for hand-washing eggs works better than immersion washers, and doesn't violate any USDA rules. It's suitable for kitchen-sink egg-washing.

The best way of washing eggs is with an AquaMagic candler/washer/dryer/grader machine. Everyone I know with a farm flock bigger than 200 hens considers these machines indispensible. These are expensive, with simple washer/dryer models starting at around $6,000 new, but they have been in continuous production for around 40 years, and old ones can often be found for between $100 and $1,000 by putting an ad in you regional farm newspaper. Beware, though, that such units are often decrepit. The machines are complex and are hard to figure out if more than one thing is broken.

Here's an egg-washing technique that ought to be acceptable everywhere, even by the strict USDA standards (but I haven't checked it with them):

1. Clean your work area before starting, and have a trash container for paper towels and broken eggs, and make sure you have a sink nearby that's not full of eggs, so you can wash your hands when they get dirty, which they will.
2. Get one or more large plastic watering cans.
3. Fill a watering can with water at about 100 F (35 C), a little unscented commercial dishwasher detergent, and enough bleach to bring the free chlorine to 100-200 ppm. Chlorine test strips are used by every restaurant and commercial kitchen and can be bought at any wholesale grocery or restaurant supply store.
4. With your dirty eggs in wire baskets or plastic washer flats, water them generously with the watering can. Allow the water to go down the drain. Letting the eggs stand in water violates USDA rules (though this may not apply to you), and tends to give rise to the same problems seen in immersion washers.
5. Let them sit for a couple of minutes. If the eggs are particularly disgusting, you might want to wet them again after a couple of minutes.
6. Take the eggs one at a time and wipe them with a paper towel. If the eggs are too dry to wipe clean, pour some of your unused wash water onto a clean paper towel. You can dip a brand-new towl in the water, but once the towel has touched and egg, don't dip it again; we want to keep the water clean. Discard the towels as they become dirty. Cloth towels are against everyone's rules because people keep using them after they're dirty. Put the cleaned eggs into another wire basket or washer flat. You may want to have a separate area for stubborn eggs that need to be sprayed and rubbed again.
7. Next comes a sanitizing spray. A watering can with 100F water and bleach at 100-200 ppm is good.  Don't stint; use plenty of water. This gets them cleaner, and the bleach helps make the stains go away.
8. Dry the eggs in some responsible manner. They'll stick to the cartons if you box them while wet. Some people dry them on racks, using 1/2 in. hardware cloth on a wooden frame. Putting the eggs directly in the refrigerator, still in their baskets or washer flats, is the simplest method.  The refrigerator will cool and dry them at the same time. Don't be alarmed if some parts of the egg seem darker than others; the parts of the egg that are in contact with a flat or another egg will dry more slowly than the the exposed portions, and will look darker. This will vanish when the egg is completely dry.

An even simpler method of egg washing is as follows: Fill a metal bucket with 160F (70 C) water and a little unscented dishwasher detergent. This water is hot enough to scald you, so be careful. Slowly pour the water over a basket full of eggs, allowing the water to go down the drain. Don't let the eggs stand in the water or they'll cook (not to mention that allowing eggs to stand in water violates the rules of the USDA and many states). That's it. The water is hot enough to sanitize the eggshells without added chemicals. This method doesn't work as well as one where the eggs are wiped, such as in the Aquamagic (using rotating brushes) or the watering-can technique (wiping by hand with paper towels), but it ought to be okay on eggs that are only lightly soiled. It's certainly simple, provided you have an adequate supply of very hot water. CAUTION: 160F water is hot enough to scald you, and pouring a bucketful over yourself is not an experience you'll forget in a hurry.

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