Soak your berries for 12 to 24 hours. You want to activate the endospores in side the berries and kill them in the cook.
Use gypsum in the soak to stabilize the pH. I used three cups into a large Turkey frying pot.
I used coffee in the soak as well. I brewed a pot of coffee over and over using the same coffee grounds and used the liquid not the grounds in the soke.
Your berries as a whole will expand, so leave some room at the top of the pot.
After they are done soaking, it’s time to dry them (with steam).
Ladell the berries and soak into a smaller pot.
Bring that pot JUST to a boil, and ladell the berries into a a colander. The key here is surface are, you want to spread the berries up the sides of the colander. NO BERRIES ON TOP OF OTHER BERRIES. The steam evaporates most of the water. You dont want them too wet. Use you fingers every few seconds to move them around exposing wet berries. You want to be able to grab a handfull. It should kinda feel wet in your hands, but not leave behind any water residue. I remember using a paper towel test until I got the hang of it.
Once your berries are “dry” fill your jars, leaving the appropriate head space.
The lids should be in place and tops of jars covered with tinfoil, to protect your filter from getting wet.
Make sure the jars are off the bottom of the pressure cooker.
Have the appropriate amt of water in the PC, not too much to boil over the tops, but enough to finish the cook.
Cook at 15psi for 90 minutes.
Let the pressure come down in your cooker, and repeat and repeat.