Solver-verified route
- Pour Vial 3 into Vial 2.
- Pour Vial 1 into Vial 3.
- Pour Vial 2 into Vial 1.
- Pour Vial 4 into Vial 3.
- Pour Vial 2 into Vial 4.
This route uses 5 pours and reaches a mixedness score of 5 out of a possible shuffle depth — the solver explored 8 board states to find it.