The fruit went tough

The three

Tough fruit is almost always a sugar problem rather than a cooking problem, which is why cooking it longer makes it worse. Three mechanisms produce it and all three come down to sugar reaching the fruit faster than water can leave it.

• Starting the cooking of the fruit in syrup that is too heavy.
• Not plumping the fruit properly.
• Overcooking.

Tough and shriveled are the same mistake

These look like two different failures and have one cause, which is useful because it means one fix addresses both. A piece of fruit that has given up its water to a syrup it could not keep up with ends up small, dark and chewy.

Both lists point at a syrup that was too concentrated too early. The fruit either collapses or hardens depending on the fruit and how far it went, which means one correction addresses both: bring the concentration up during the cook rather than starting there.

What plumping means in practice

Plumping is just letting the sugar arrive slowly enough that the fruit can equilibrate instead of collapsing. In a kitchen it costs you time rather than equipment, and it is the step most often skipped when a batch is running late. Which is the point worth holding on to: the batches that come out tough are usually the hurried ones rather than the badly judged ones, and no amount of care at the stove recovers a step that was skipped before it.

Giving the fruit time in the syrup, off the boil, to take sugar in before the water starts coming out. It is a wait rather than a technique, and it is the step that gets skipped when a batch is behind.

References