I plan on brewing NB's Octoberfest this weekend. The OG of the 5-gallon extract kit is 1.058. My WYeast 1007 Smack Pack, which has been refrigerated upon arrival has a manufacturer date of Nov. 14, 2014. I just went to http://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/ and put in the calcuations and it said, given my non-stir plate starter method I would need a 5L starter. The yeast is 86 days old and as a result has a 40% viability rate. Does this seem right?! I've never used a pitching calculator, but I didn't think a 5L starter would be necessary to brew a session beer. It's not like 1.058 is some barley wine. I get that the yeast is a little old, but a 5L starter?! Should I just make it in a gallon jug? Has anyone else ever needed a starter this big? I don't want to underpitch, but a 5L starter seems odd to me. Lastly, for my other starters I just used a 1L flask with a foam stopper. I now have an airlock that fits my gallon jug. Should I use that or put the foam stopper in the gallon jug? I've read conflicting things about using airlocks for starters. But, I use the airlock for a 1-gallon batch of beer, so what's the difference?