Recently, I have started re-using yeast from batch to batch by getting (top cropping) ale yeast. Currently, I brew every two weeks and my procedure has been this: Brew one day on the weekend, then the next day make a 2 quart starter with DME and top crop 1 cup of yeast and put that in the starter. After the starter ferments out (about 4 days or so) I chill the whole starter for a little over a week until I brew again, in which I let that starter warm up to room temp and pitch the whole volume in the beer. So far, about 7 or 8 batches, I have had good results (using White Labs WLP001). Next May, my wife and I are expecting twins and this will most likely greatly limit my homebrew days (not every other week like it is now). I have been planning ahead, a I likely will double my all grain batch size to 10 gallons and brew once a month if time permits. Now, finally to my question, will the yeast keep in the starter in the fridge for 3 weeks? Or, should I learn how to somehow keep the top cropped yeast on an agar? I am just curious. I would rather not buy a new pitch every brew day. Side note: as of now, I plan to buy a new pitch everytime I re-order bulk ingredients, just in case the yeast I am using starts to "genetically" drift. Thanks in advance guys and gals.