Well that's rotten
Tomato blossom end rot....the bane of many ambitious gardeners who have toiled for months only to find the setting fruit rotting on the vine. Contrary to popular belief it does not appear to be a watering issue or a disease, but rather a calcium imbalance in the soil. I recently learned that simply adding egg shells to the soil can help considerably. So I dumped the morning's breakfast on one of my container plants, scratched it in a bit, and will patiently cross my fingers that 'The Rot' does not tamper with my laboriously tended tomato.