Pulled out half the contents of my storage cupboard and found some cree xpe far red leds I had stashed in there. These have been soldered onto modified pcbs, and i suspect because I hand soldered I may have hurt some of them.
Using the diode function on my multimeter I managed to quickly sort them into 5 groups. Starting at 1.439V going up to 1.445V. Four of the eight came out at 1.441V.