4 mo. Old smack pack

Hi All, I’m planning a brew this weekend and realized my WY1272 is dated Jan 21. I intended on making a 1L starter for my 1.057 OG anyway but now I’m not so sure. If I do a 1L and then step it with another 1L, do u think I could get by? I’ll make the starter tonight to ensure activity. Alternately I have 1pack of US-05 that I could use instead, as back up or in tandem. Any words of advice?
Thanks, Mike

Get by is the operative term in your overall yeast starter approach just stated. Optimal is fleeting with many of those parameters you just explained.
Even if the yeast was produced today and handed to you directly from the lab a one liter starter for a 1.057 SG beer is off some. IE:optima=209b 100% viable yeast + 1L=186b its close enough for government work but you may want to look towards bigger starters than 1L especially if making beers that inch close to or well above 1.060

For the 1.21.12 yeast you have 10% viability. I would actually say no larger than 1L should be your first step. ( 10b cells + 1L=54b ) Then a one liter 2nd step = 136b if you actually shake/swirl the starter a few times otherwise the yeast growth is quite a bit smaller.

A second step of 2L gets closer (187b) But ultimately a 2.5L starter puts you on optima for 1.057(207b)

Storebought or DIY stirplate is really where its at especially if you plan on doing high gravity or lager brewing often with liquid cultures. For the current brew if you dont want to make the nessecary starter, I would advocate for just using the full sachet of US-05 and that is more than ample pitch rate.

Thank you for the information. If I start with 1L and let it ferment and crash it, would I make 1.5L or 2.5L for the next addition? And, it is good to know if I don’t take that route my sachel of 05 will work. I was hoping for some yeast flavor from the 1272 however.
Thanks, Mike

You would decant the spent 1L wort and pitch the slurry into a 2.5L wort for optimal cell count.

Again, thank you. One last one here; I have a 2000 litre beaker, would this allow enough room for growth at the 2.5l starter stage?

2500ml will not fit in a 2000ml flask is the only answer I have for you unless I misunderstood the question.

My bad

You could use a gallon jug or jar. I use 1gallon wine jugs but apple juice bottles, milk jugs, etc, all work well. Be sure to thoroughly clean and sanitize!

Thanks!