Beer Forum

What is the best way to ramp-up a 4 month old yeast tube to pitch in to 5 gallons of 1.056 beer? I was thinking of doing a 1 quart starter, and then pitching it in to a 2 qt starter on a stirplate. Or I could do a single, big starter.

Any Thoughts?

Here's what I thought at first:
4 months isn't all that old. Has it been in the fridge the whole time? If so, I'd go straight to a 1.8L starter in a 2L flask on the stir plate and pitch it in 24 hours.

Then I plugged those numbers into Mr. Malty and it said:
With the 11% viability of a 4 month old tube, you need 4 tubes in a >2L starter to make 5 gallons.

Holy moly I was way off I guess. Perhaps stepping it up like you suggest is a better idea.

So if I need to quadruple the yeast in the tube, then pitch into a 2L starter. 1 liter on a stirplate should be plenty to quadruple it, right? Then just do a 1.5-2L starter on a stirplate...

Sorry, not so good at math.

It's more than that, even. The 4 tubes were the amount needed to go on a stir plate starter in 2.2L of wort to get you to the right amount for your 5.25 gallon batch.

Play around with the Pitching Rate Calculator and see what you can work up.

don't obsess too much over it, though. You will still get beer at the end of it all. Even though the 1L->2L you propose is underpitching, it will still work. You might want to have an emergency pack of dry yeast around in case the lag gets excessive.

Thanks man.
I think I'll go with 1L on a stirplate, and add that to 2L more on the stirplate. No reason to skimp on this.