I have this recipe for a Helles Bock that I've been wanting to make and I ran into a slight hiccup. The OG is 1.069. According to Beersmith and mrmalty.com I'm going to need 4 smack packs and a 3.5L starter. Would it be possible to get the same amount of viable cells from 1 smack pack by using a 2L starter, pitching the yeast, fermenting, cold crashing, decanting the spent wort, and repeating the process 3 or 4 times? Is this achievable or do I need to buy 3 more smack packs?