How can you tell the difference between Barred Rock egg and a Black Sex Link egg?

[corvid]

Is there any definitive way to tell the difference between BR and BSL eggs? I would like to sell fertile eggs or chicks once my chooks start laying but I only want to hatch and sell Barred Rocks. I only have BRs and BSL and the only rooster I have is a BR. They should start laying in January of 2022 if everything goes smoothly and they're comfortable enough. Thank you.

 

[sourland]

Egg shape and color can vary greatly from bird to bird regardless of breed. The only way to be sure is to use trap nests or separate the hens.