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**Yeast and Fermentation / Re: Stepping up a Starter**

« **on:**February 13, 2010, 11:40:06 AM »

I love the MrMalty calculator, but doing two-stage starters with it can be frustrating.

One simple alternative is to use the Wyeast calculator (http://www.wyeastlab.com/hb_pitchrate.cfm). It does have some limitations: works only in gallons, no adjustment for viability, and gives results as pitching rate rather than cell count, without allowing for decanting the starter.

BTW: I'm assuming you can't get a stir bar to turn in your gallon jug, so I'm using "intermittent shaking".

Anyway, here's how to spoof MrMalty:

1. Set your production date, then play with the gravity and/or volume fields to get the volume of your first stage (I'll use 1 L).

2. Note the number of cells that grows (178B).

3. Turn off the automatic viability calculation and enter that number for the viability.

4. Enter your real gravity and volume, and the calculator will tell you the volume of the second stage (2.24 L).

5. Verify that the volumes are realistic and adjust the first-stage volume if needed. Ideally, you want to at least double the volume at each step.

When making the starter(s), be sure to allow enough time to chill and decant at each stage before stepping up.

One simple alternative is to use the Wyeast calculator (http://www.wyeastlab.com/hb_pitchrate.cfm). It does have some limitations: works only in gallons, no adjustment for viability, and gives results as pitching rate rather than cell count, without allowing for decanting the starter.

BTW: I'm assuming you can't get a stir bar to turn in your gallon jug, so I'm using "intermittent shaking".

Anyway, here's how to spoof MrMalty:

1. Set your production date, then play with the gravity and/or volume fields to get the volume of your first stage (I'll use 1 L).

2. Note the number of cells that grows (178B).

3. Turn off the automatic viability calculation and enter that number for the viability.

4. Enter your real gravity and volume, and the calculator will tell you the volume of the second stage (2.24 L).

5. Verify that the volumes are realistic and adjust the first-stage volume if needed. Ideally, you want to at least double the volume at each step.

When making the starter(s), be sure to allow enough time to chill and decant at each stage before stepping up.