Within the next few days I'll be 'brewing' 100 litres of ale from slightly concentrated sterile wort. I've used these kits before with decent results, but this time I want to try a liquid yeast instead of the packaged dry (Cooper's) yeast that's included in the box. So I bought a Wyeast 'Direct Pitch' smack pack (British Ale II) that allegedly contains 100 billion cells.
Not enough for this much wort, obviously, so I propose to boil up half a pound of dry malt extract to make a 1/2 gallon starter. When that's rolling nicely I'll use it to pitch this next mega-batch. Good idea? Bad idea? Any reason that wouldn't be satisfactory?
Much of my homebrewing knowledge, if you can call it that, dates back to Neolithic (i.e. pre-Internet) times, so until I can lay my hands on some good recent books on the subject, I thought I'd ask the question here.