You waited all season for that first red ripe tomato only to discover less-than-perfect fruit. But don't worry, you can still have a great harvest and improve things for next season.
Blossom end rot is a common problem on the first set of fruit. It's due to a calcium deficiency often caused by fluctuations in soil moisture often seen in container grown tomatoes.
Cracked fruit are also common in the garden. Fluctuating temperatures, moisture and improper fertilization result in irregular development of the fruit that results in cracking.
Control both these disorders with proper care. Water thoroughly and less frequently to encourage deep roots. Mulch the soil to keep it evenly moist. Be sure to avoid root damage.
However affected tomatoes are safe to eat.