Yeast viability question

[Clanchief]

I picked up a packet of Wyeast 1272 back in January, anticipating that I would be brewing with it shortly after it arrived. It was produced on 12/28/12. It has been kept in the refrigerator since arrival, but because of life happening, I haven't had a chance to brew the beer I meant to. Now, I was hoping to brew with it this weekend, but I ran it through Beersmith and was basically told that while I need 281 billion cells for my 1.083 OG beer, the best I can get out of the pack, even on a stir plate, is 171.8 billion. So that would be a dramatic under-pitch, which I obviously do not want.

I had thought to go to the LHBS but the one closest to me, and the only one I really had access to today, apparently just recently went out of business.

Do those with a bit more yeast experience than me think that a 2L starter on a stir plate would be viable for a beer this size with this aged yeast?

 

[mtnagel]

If you do 2 x 1L steps, you could get to 241 billion cells. You could either do one today and one tomorrow and then pitch later Saturday night or more ideally brew on Sunday and give the starters ~24 hrs each.

 

[kh54s10]

http://yeastcalc.com/ Has information on making stepped starters. http://www.mrmalty.com/ is another good source of information.

I didn't crunch the numbers to see if this weekend is feasible.

 

[mtnagel]

Or if you do a 0.75L starter and then a 1.25L starter (without decanting in between), you can get to 251 billion cells. This is using the Jamil stir plate setting on yeastcalc, which I heard is more accurate than the Troester stir plate option, which says you can do it in 1 step.

 

[Clanchief]

I've never made a stepped starter, so that worries me a little bit. Also, I only have a 2L Erlenmyer, and my stir bar isn't crazy huge, so I'm already concerned with it trying to push a full 2L with that bar. Things to think about...

 

[mtnagel]

My stir bar is small too. Maybe an inch and I have to turn my homemade stirplate almost all the way down to not have a vortex on a 2L starter in a 2L flask.

 

[CA_Mouse]

I've never made a stepped starter, so that worries me a little bit. Also, I only have a 2L Erlenmyer, and my stir bar isn't crazy huge, so I'm already concerned with it trying to push a full 2L with that bar. Things to think about...

This is actually fairly easy to do. I would create a 1 liter starter as soon as you can. Place it on your stir plate and let it go until 20 to 24 hours have gone by. Cold crash it. While it is chilling, make a 2 liter starter of the same OG. When the second starter is about ready to be pitched, decant as much of the spent wort from your 2 liter as you can and pitch the remaining slurry into the 2 liter starter. Place it on your stir plate and let it go for another 20 to 24 hours. Start your brew day on Sunday with the anticipation of being able to pitch your yeast as close to the 24 hour time. Basically you are allowing the yeast to start reproducing, so you should gain about 35% to 65% increase in the cell count with each starter. I wouldn't worry too much about a small stir bar. I routinely use a 1" bar in my 2.5 liter starters without any real problems. In this instance, you might be over pitching slightly, but not more than an acceptable level.

Mouse

 

[mtnagel]

I'd worry that with a short cold crash period that all the yeast isn't dropping and you might be tossing yeast when you remove some of the liquid between steps. I always crash for a day or two, so I'm not sure how much though. That's why I recommended just doing two starters that would fit into the 1 flask so you didn't have the crash step.

 

[tre9er]

Just make a 1L starter, then after a day add wort to bring it up to 2L. You might want to add some yeast nutrient too if you have some.

 

[tre9er]

do you have any other yeast on hand? If you have another somewhat clean ale yeast, you could supplement with that, too. I don't think it's going to drastically affect your beer. What style is this beer? Looks like a DIPA to me...?

 

[tre9er]

Lastly, if you get up to a certain percentage of the needed cells, just pitch that into the same percentage of your wort. Ie. if you get to 75% of the cells you need, pitch it into 75% of the wort, then seal off the remaining 25% for 48 hours, then re-combine.