Try to scratch the blade with a file. If you can scratch it then the blade didn't get hot enough. Sometimes the thermal stress created by quenching is so severe that the blade will spontaneously crack. Consequently the next step, tempering, should be done very soon after the blade has been quenched and hardened. The goal is Rockwell C-62.
Many books give a slightly different recipe for tempering carbon steel.
Heat the blade slowly until you see a colored oxide form on the surface of the blade. When the color is just right plunge the blade into water. That's the way it was done by the village blacksmith. Welcome to the 20'th century. I don't think oxide colors are as accurate as a thermostatically controlled kitchen oven.