Advice for multi-stage yeast starters, please?

Ingredients
1

I’m looking for advice on a 2- or 3-stage yeast starter. I’m thinking of the following method, so would some of you more experienced folks lend a hand with a confirmation and/or advice, please?

My equipment: 3000ml Erlenmeyer flask (boro), stir plate, Wyeast yeast, DME, Wyeast nutrient blend

Here’s what I’m planning:
If I do a 1.5L starter, assuming 100B starting yeast cells, I should finish with 181B cells (i.e. 1.8x multiplier). If I split the starter into 2 flasks, each being a 2nd stage (using chill & decant), wouldn’t I end up with (0.9B * 1.8) * 2 = 3.24B cells?

2

I’m not sure where you are getting your numbers from, but my calculations give wildly different results, Try the calculator here:

or this one:

3

If you don’t do an actual cell count you’ll never know. The most important thing is that you pitch viable yeast, and that your cell count is in the ball park. There are a number of calculators out there that will do this for you.

Instead of splitting the starter into separate flasks, you have the option of decanting the 1st starter and add fresh wort on top of the existing yeast cake in you Erlenmeyer flask.

4

The yeast calculator in BeerSmith also works pretty well.  It too will  get you in the ballpark.

5

Assume 100-150 billion new cells per liter of ~1.030 wort. If you want to end up with ~320B cells total, put the pack in a 2 L stirred starter and if anything you’ll probably be overpitching a bit.

6

To quote Chris White, “homebrewers are too hung up on numbers”

7

Assume a 2L starter will start your beer.

8

1L is what I use for almost everything

9

So it’s safe to assume 2L will do the job.  You know, not getting hung up on the number of liters either.  :slight_smile:

10

Absolutely!  You’ll just be pitching more starter wort.

11

OP said he was planning to chill and decant,  so no worries there.