Make up a 1-2 pint of must, gravity ~1.040. Boil for 30 minutes, cool to room temperature. Pitch one vial, shake well and let sit for 1-2 days. Little to no activity will be seen in the starter, since this is a very small volume compared to the quantity of yeast pitched. The yeast in a starter may be done within a couple of hours. But a layer of yeast should be at the bottom after 1-2 days. The must on top of the yeast can be either decanted off the top, or left in and pitched with the whole volume. Most pitch the whole volume, but if the starter gets to the point of 2 liters for 5 gallons, then we recommend decanting the must off the yeast.
Typical Starter Volumes for 5 gallons:
To activate the yeast: 1 pint