When buying eggs it is important to pay attention to the expiration date. Eggs are at their best when they are less than 25 days old. Open the egg carton to make sure that that none of the shells have cracks or dirty fecal matter on them. Don't be surprised this does happen so it's better to check.
How can you tell if eggs are old?
Place eggs in a bowl of fresh cold water. If the eggs floats or stands up on its side they are old, if they sink to the bottom of the bowl they are fresh. As eggs age they start to break down and release gas this increases buoyancy so old eggs float. Eggs that float to the very top of the bowl are extremely old and should not be used.
Most Expensive: Organic egg layers are fed a diet of organic produce and ranged on organic land. Organic eggs contain more vitamins and minerals and do not contain pesticides or herbicides.
Moderately Priced: Free-range are allowed to roam freely during the day and eat outside vegetation. At night they stay in low density hen houses or barns; they are not confined in cages.
Average Price: Cage-free egg layers are high density houses with an attached yard pen outside. Cage-free eggs are modeled after the factory farm system without the cages.
Cheapest Price: Factory farmed eggs are raised for production, animals are confined to cages, exposed to 24-hour-a-day-lighting, injected with hormones to increase egg production, fed corn sprayed with antibiotics and fed the cheapest food that makes them produce faster and larger quantities. They are fed genetically modified organisms (GMO) and animal derived byproducts.