Hi Ian,
Hmmm, 3 lbs is not quite 1.5 kg, and I routinely get 1.5 kg of green cheese from 10 L of cow's milk. After it's air dried, and sits in the cave for awhile, it usually drops (as much as 500 g). I've had two cheeses produce over 1.7 kg after pressing, the above mentioned butterkase and also a manchego (which just bumped over 1.7). The manchego lost over 300 g while air drying, and the butterkase started at 1836 and is now 1384, so it's lost 500 g since make day. So, to me anyway, your yeild does not sound all that unreasonable. Especially if you had a soggy curd to start.
- Jeff