I'm doing an experimental canning batch of wort starter as I type. I used a 1 lb package of DME and divided it 4 ways into pint jars which fit perfectly into my 6 qt Cuisinart. Filled each jar with hot water 1/2" from the top, a pinch of nutrient and screwed lid and ring into place after stirring to dissolve. Calculations are that 113 grams of DME in this pint, then diluted to a volume of 1 liter when used is close to the right amount. This ratio allows me to split a 1 lb package of DME evenly between 4 pint jars.
Filled cooker with water about 2/3 way up the sides of jars, and it only took a short time for the Cuisinart to come up to pressure. The cooker just turned off after 30 minutes under pressure at appx 15 psi. The entire process took around 1 hour.
This method is so much easier than boiling one single starter at a time. If by chance NB should announce that Fast Pitch is now back in stock....sorry Charlie, but I found a new dance partner!
EDIT: Jars did fine and the lid "Popped" down perfectly as planned. This is an easy way to produce starter concentrate...just wish I had discovered this sooner.