Ok, I just looked it up. It's weather related.
"Catfacing is a tomato disorder that causes fruits to develop puckered surfaces and distorted shapes. Bands of tan-colored scar tissue may also run across the blossom end of the fruit.
The disorder occurs when weather conditions interfere with proper pollination and fruit development. Cold weather (below 50°F) and hot weather (above 85°F) can both cause catfacing. Dramatic fluctuations in soil moisture can also cause tomatoes to develop cracks in the stem end of the fruit. These cracks may be radial or concentric; rot may set in at the cracks, or the cracks may heal over with corky, brown tissue. Heirloom tomato varieties, especially those that produce very large fruit, are particular susceptible to catfacing and growth cracks."
Italics mine. And we've definitely had both.
Well, humph.
"Catfacing is a tomato disorder that causes fruits to develop puckered surfaces and distorted shapes. Bands of tan-colored scar tissue may also run across the blossom end of the fruit.
The disorder occurs when weather conditions interfere with proper pollination and fruit development. Cold weather (below 50°F) and hot weather (above 85°F) can both cause catfacing. Dramatic fluctuations in soil moisture can also cause tomatoes to develop cracks in the stem end of the fruit. These cracks may be radial or concentric; rot may set in at the cracks, or the cracks may heal over with corky, brown tissue. Heirloom tomato varieties, especially those that produce very large fruit, are particular susceptible to catfacing and growth cracks."
Italics mine. And we've definitely had both.
Well, humph.