Looking for ideas

I work at a botanic garden and recently got a hold of some ornamental pears. The name of the pear is Pyrus ussuriensis 'Mordak'. The pears are about the size of a golf ball, sour like a lemon, and have tannin levels that will dry your mouth out. If you have ever tasted an acorn, this is about the same. They smell strongly of fresh ripe pears.

I have made many batches of cider in the past, but have never made a perry. I have about 4 one gallon freezer baggies full of these in the freezer. I do not have enough to do a true perry, but I was thinking of using some of these with a batch of apple cider to both add flavor and tannins.

I currently have 3 gallons of fresh pressed cider from Michigan(mainly 'Golden Delicious'), and 3 one gallon bags of the crabapple Malus 'Dolgo' to work with.

Anybody have any ideas on how I should use these. Remember, they are incredibly tannic. Any and all ideas will be considered and appreciated. Except shipping the pears to your house.
Thanks

The first thing to do is test the fruit for sg and pH. Normal pear juice has high pH and mid-range sg. Perry pears have lower pH and higher sg. Testing will give you an idea of the quality of the juice. Sounds like the fruit will be good for adding body to cider (or perry). I got some seed of Pyrus pashia (himalayan pear) from the collection at Corvallis in Oregon, the fruit is said to be astringent so I plan to try fermenting it for a perry. The trees are 2yo and 2 metres tall.

Thanks. Without a doubt, these are low pH pears, not sure on the specific gravity yet. I doubt I have enough of them to get a decent amount of juice, but will most likely break them and add them to a batch of apple juice, I am just unsure of the quantity to add due to the astringency. If I add too many, will the tannins "mellow" over time like they do for grape wines? I will watch this closely as I would hate needing to age it for 10 years to mature. It would be nice to drink them next summer.