They are beyond the store ones by a damn site. Burpee bred one called ‘Long Keeper’ especially for this technique. They are about the size of those pink rubber balls and as hard as marbles, but by New Years you can have something fresh still. Burpee used to ship the seed as a thank you gift with your order. And I have seen those at the seed kiosk at walmart. When I grew those in ‘92 Mom and I had a BLT on New Year’s eve. That’s when the light bulb came on. We found out last winter that you can crack open a jar of whole tomatoes and use them on tacos. Kick@$$.
My record for last ripe tomato is February 16 which was last year. Coincidently that’s the earliest I’ve ever gotten ripe ones in the greenhouse. Split a ripe one on BLTs with Dad and he about did a backflip. That was 2001.