I have a small (4 qt) stainless stovetop pressure cooker... the low-tech kind with the jiggling weight.

I took a lb of chicken hearts (they were well cleaned, no blood or gristle), browned them very well in the cooker, browned an onion and a bunch of garlic, tossed it all in with a bottle of Summer Ale, and cooked it under pressure for 30 minutes.

After browning, the hearts were a little chewy, but tasted very good... kind of a fried-dark-meat-chicken type taste. After pressure cooking, the hearts actually seem to have gotten tougher.

I figured they just needed more time, so the hearts spent another 20 minutes under pressure with another half-can of cheap light beer added. No real change, although at this point the vegetables have disintegrated into a thick sludge.

After this much time in the pot, the hearts had taken on a gamey/livery taste.

During cooking the pressure was set to the point that the weight "danced" and vented steam in a slight hiss, not at full "is my kitchen going to explode" throttle.

I'm new to pressure cooking, but I have a freezer full of tough wild boar meat that would greatly benefit from me figuring out how to make tough meat tender instead of making slightly tough meat tougher. :-)

Any advice would be appreciated.