It’s SO very important to us that we deliver a high quality product to every customer. This customer uses a technique called floating to check the freshness of eggs prior to cracking. If you have not tried it before you place an egg in a bowl of cold water and see if the egg lays flat, comes up on its end, floats partially or fully to the surface. She mentioned to me that with the eggs she gets from us, some float in fewer days than the eggs she gets from the store. I felt I needed to test this on our eggs to see what I could figure out since I feel confident that our eggs are fresher then the eggs that have traveled 1000’s of miles to get the the store. | Did you know that the food in the store travels an average of 2000 miles before it get to the shelf?
But that’s a whole other topic. Back to the eggs | First to understand how and why this float method works we much understand the composition of an egg. When a chicken lays her egg, her body seals the egg with a coating called a cuticle or bloom. This coating helps keep air and bacteria out on the egg and keeps the moisture in. Once that bloom is washed off, the egg shell become more porous, meaning moisture can escape and air can get in. As that transfer of air and moisture progresses, the air chamber at the end of the egg gets bigger and the albumen (egg white) shrinks a bit. As the air space inside the egg grows slightly, the eggs becomes more buoyant in water. The picture below shows the parts of an egg. | | | Next we need to talk about egg grading. Any eggs you buy in a grocery store are required to be graded. This grading goes from AA-C for eggs. We see this grading in all sorts of fresh food from eggs to meat to produce. The grading has little to do the the quality or nutrition of the product and is more about the appearance. ‘Fancy’ carrots have to be fall within very specific measurements for size and color. It’s often about making food seem very homogenous. The fact of the matter is food is a natural process, meaning there will be variation. Below is an egg grading chart. In a commercial operation the eggs are run through a grading and candling machine that weighs, measures, looks at shell color and finally shines a light through the egg to see the air pocket and check for impurities in the egg. 40% of eggs laid in the US don’t receive AA or A grading. They go off as grade B eggs to restaurants or get made into other processed egg products. | | Based on sizing and shell consistency of these grading guidelines, I would say we would probably only be able to grade about 30% of our eggs as AA. If you get your eggs from us at the farm or through direct order you may have noticed on the label that it says “these eggs are not from a government approved source”. That’s because the eggs that we sell directly to you are usually the ones that fall outside the grading standards for commercial eggs. I believe there are 2 main reasons our egg fall further outside the range than the ‘egg factory’ eggs.
First we run small flocks of hens, 350-500 birds in a flock vs the 500,000+ in a commercial operation. We allow them to grow out the way each bird is meant to. We don’t cull hens that are larger or smaller than the “ideal” for laying, making for more natural variations in the eggs. This means our hens lay non-homogenous eggs that vary in density, shape, and the air pocket at the time of lay.
Second because our hens are out on pasture moving and exploring, their eggs have more variation in general than the eggs coming from hens raised in a commercial operation. We have some hens that are fine eating only the feed we provide them and some that are out eating mostly what they find in the pasture. Which creates differences in the yolk color, shell shape and size. Even ‘free range’ eggs come from hen that have little or no time actually outside with bugs, grasses and sunshine, because ‘free range’ simply means there is some outside access. Likely this access is an open door at the end of a very large barn filled with 100,000s of hens.
Back to egg floating…so after I got the email from the customer concerned about the floating I wanted to test a variety of our eggs to see how they’d do in the float test. First I pulled out the oldest eggs we had, they were about 48 days old, these are the eggs I was holding back for hard boiling, they were mostly XL and jumbo egg, but some Large and Med as well. I floated 30 of them and about half came up on end and 1 floated off the bottom of the bowl. I took the full float egg to see how it faired when I cracked it and this is what we saw. | | As you can see in the picture it still has a very well shaped yolk and a firm white. I also fed this egg to Farmhand 4.
Next I tested eggs that are about 10 days old. 2 of the 6 came up on the end.
Finally I floated 6 eggs that were laid within the last 24 hours. And 1 of the 6 came up on its end.
In researching deeper about egg grading and freshness we also learned about the Haugh Unit which is a method used the measure the protein and freshness of eggs developed by Raymond Haugh in 1937. An egg is weighed, then broken onto a flat surface and a micrometer used to determine the height of the thick albumen (egg white) that immediately surrounds the yolk. The height, correlated with the weight, determines the Haugh Unit, or HU, rating. The higher the number, the better the quality of the egg (fresher, higher quality eggs have thicker whites). Although the measurement determines the protein content and freshness of the egg, it does not measure other important nutrient contents such as the micronutrient or vitamins present in the egg.
So we wanted to test this out and luckily Asa is a math whiz and could work the formula for the Haugh Unit. We again tested this on our least fresh eggs, you remember the ones I hide in the back of a fridge for us to hard boil. We weighed the eggs so we could test both a Large and a Jumbo egg. To fully test we also floated both eggs before cracking. The Large egg stayed on its side in the water and the Jumbo floated slightly off the bottom of the bowl. We cracked and measured the white next to the yolk (full disclosure I did not use a micrometer, but rather a toothpick and a ruler). Asa then did the following math:
The formula for calculating the Haugh unit is:
HU = 100 ∗ log(h-1.7w 0.37 +7.6)
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Where: - HU = Haugh unit
- h = observed height of the albumen in millimeters
- w = weight of egg in grams
Haugh Index :
AA : 72 or more
A : 71 - 60
B : 59 - 31
C : 30 or less
The Jumbo egg (the one that failed the float test) scored a 92.0.
The Large egg 93.8.
Our conclusion after this is that the ‘float test’ works great to test freshness of eggs that fall in that narrow window of AA grading for size, weight and shell condition. Farm eggs that fall mostly outside of those ranges will most likely fail the float test but still far exceed protein and freshness measured by the Haugh Unit test.
Now none of these test speak to the increased nutrient value of pasture raised eggs over those of birds in confinement, but I think that’s a topic for another day.
Our worry following the concern from a customer has been put to rest. Our confidence that we are bringing you a high quality fresh egg is restored. It’s funny how one person’s negative experience can over shadow 100’s of positive comments. In the end I’m grateful for the feedback that lead us to investigating and testing because it allows us to have more knowledge on the subject. We always want to hear from you, especially if you find something that does not meet your expectation of quality.
Ultimately farm food will have more variation and character than factory food.
Thank you for reading and being part of the change from factory food to farm food!
Have a wonderful week,
Aila |
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