determining how fresh an egg is

[mcohen]

is there any way to determine how fresh an egg is before you buy it and take it home? after doing the water test where you put eggs in cold water, i've recently discovered that the eggs i've been buying from the farmers market is actually older than the regular eggs i buy at the grocery store.

seems like more and more vendors at farmers market are getting the benefit of the doubt from the halo affect, and getting away with such shenanigans.

[sparrowgrass]

Nope. That shell can hide a multitude of sins.

The cold water test only shows how much evaporation there has been from the egg.

A washed egg will dry out faster than an egg that hasn't been washed, because eggs naturally have a barrier against evaporation. If you take 2 eggs laid on the same day, wash one and put it in an uncovered bowl in the fridge, leave the other unwashed and store it in a carton, the washed one will float much sooner than the other.

The only real way to check freshness and quality is to crack the egg out onto a plate, and look at color and how thick the white is. The runnier the white, the older the egg.

A really fresh egg will stand up--the yolk will be high atop a nice mound of white.

[gperls]

On the end of the carton, right before the expiration date, is a 3 digit number which represents the julian date the eggs were packed. This is a pretty good indication of how fresh they are. And you're right, sometimes the factory eggs are fresher than the farm-fresh, local, organic ones.

[Mallet]

Nope.  That shell can hide a multitude of sins.

The cold water test only shows how much evaporation there has been from the egg. 

A washed egg will dry out faster than an egg that hasn't been washed, because eggs naturally have a barrier against evaporation.  If you take 2 eggs laid on the same day,  wash one and put it in an uncovered bowl in the fridge, leave the other unwashed and store it in a carton, the washed one will float much sooner than the other.

The only real way to check freshness and quality is to crack the egg out onto a plate, and look at color and how thick the white is.  The runnier the white, the older the egg.

A really fresh egg will stand up--the yolk will be high atop a nice mound of white.

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I was always told that as eggs rot, they release gasses which get trapped in the egg. Rotten eggs are full of gasses (incl. some sulphurous compounds), which is why they float. It's a bit less benign than evaporation. Unfortunately, not all farmer's market eggs have packing dates, which can make things difficult. Can you simply ask the farmer how old his/her eggs are?

[Anna N]

On a number of occasions I have tried to determine the age of super market purchased eggs but here in Canada the only information I can find on the cartons is a best before date! I have googled for more information with no luck. The only info that seems to be pushed is that eggs are "fresh" if properly refrigerated and used before the best before date! Hmmm - I think more openeness is in order!

I, too, have been extremely disappointed with eggs purchased from Farmers' Markets. I think the super market eggs are fresher!

[sparrowgrass]

Mallet, it is true that rotten eggs produce gas and would float. However, I have been cooking for ( OMG ) more than 40 years, and out of hundreds of dozens of eggs, only once have I cracked open a "rotten" egg.

You are much more likely to find a stale egg than a rotten one.

[Ted Fairhead]

On the end of the carton, right before the expiration date, is a 3 digit number which represents the julian date the eggs were packed. This is a pretty good indication of how fresh they are.

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The only problem with that, according to a newspaper report I read a couple of years ago, is the shop assistant who takes out the broken and cracked eggs from one carton and replaces them with eggs from another carton, to put back on the shelf. Dates on cartons aren't reliable, in my opinion.