When I make a yeast starter, I use DME - usually about 200 gm for a 2-liter starter. Often for lagers, I repeat this one or two times, depending on how old or healthy the yeast is. This can be relatively costly in terms of the amount of DME that is used. I have heard that some people make wort specifically for this purpose, and store it (freeze it?) for later use. I would be very interested in hearing about the various practical approaches that homebrewers have used to accomplish this. Thank you!