Might have a top or second ring stuck or not sealing. A small mark on the piston by the ring, or small piece of dirt in the ring land, could hold a ring up. The oil ring can be doing its job, by keeping oil out of the combustion chamber. It doesn't do much for keeping combustion out of the crankcase with its low tension.
It's a lot of work to check, but if it wasn't like that before, then something isn't quite right.
Aside from that, and to be more relative to your question.... Similar to a PCV system with a catch can, I've seen industrial engines have special canister with an element inside. They run in after the air filter (or intake manifold like a PCV), to draw the crankcase pressure down. The coalescing element catches the oil vapor, and the catch can has a small line for oil to drain back down to the oil pan. They have relatively large lines, so tend to draw too much vacuum in some instances. A flow control valve is then installed, to keep crankcase pressure at -1"H2O. Just an idea for you, but may be too much, for under the hood of your car.