Once mine are red everywhere, including up to the stem, they are usually pretty ready. At that point they have some give, but not a ton. For saucing and canning whole you don't want them too soft -
Hmm, so if the flesh is a pinkish-red inside, that's good enough for sauce/drying?
Typically, the flesh of mine inside is medium/light red all the way through, with a seed cavity that's filled out. Underripe romas sometimes have "hollow" looking seed cavity. Some paler streaking down the core is normal, but not white or light pink.
The old skool way of categorizing these things (tomatoes, peaches, etc.) was:
"firm-ripe" - the ripeness at which the fruit was fully mature and colored but still firm enough to ship without damage to the fruit. At this point the fruit will look good, but honestly it won't taste the best. Pears and peaches will still be a bit crunchy, tomatoes may have a paleness and "supermarket" flavor.
"canning-ripe" - the riper stage where the fruit is slightly soft and the flavor has developed further but the fruit is still firm enough to process without falling apart. At this point, the fruit would taste very good eaten fresh and - in the case of things like peaches, there would be no sign of "crunch" or "tooth" to the flesh, but the fruit would not require you to stand over the sink for fear of a juice explosion. Ideal stage for canning.;
"soft-ripe" - the stage at which the fruit is fully juicy and sweet. Ideal for fresh eating, but impossible to ship and too ripe for quality processing because fruit at this stage bruises and falls apart if you look at it firmly. Tomatoes at this stage are very dark red all through the flesh, as juicy as their type will allow, and soft under the skin (most tomato skin is firm enough that you kind of have to feel "past" the skin to assess softness of the flesh.)
Anything past this is over-ripe. Over-ripe fruit will puddle from its own weight within a few hours if you set it on the counter. Decay may have started to set in. While it's tempting to use over-ripe "seconds" for canning, this should be avoided since the tomatoes become less acidic.
