Change starter's OG in method C. White Shaking don't change the final result

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Hi, I'm trying to use the starter calculator, but when we change the OG of the starter's wort using the C. White Shaking method, the final quantity of viable cells does not change. In the Stir Plate method it changes, but not in this one. Naturally the wort density is a crucial factor for the propagation of cells, and the same result appears for OG 1010 or 1090. What to do?
 
Hi, I'm trying to use the starter calculator, but when we change the OG of the starter's wort using the C. White Shaking method, the final quantity of viable cells does not change. In the Stir Plate method it changes, but not in this one. Naturally the wort density is a crucial factor for the propagation of cells, and the same result appears for OG 1010 or 1090. What to do?
Hello,

In general, changing the gravity of your starter is not recommended. A SG of 1.036-1.037 is recommended as it's the best balance between yeast vitality (nutrients), yeast viability, growth rate, and growing in a not stressed environment.

With that said, the C. White growth is taken from the published book below, and is simply based on some experimental data that relates growth rate to the inoculation rate.

White, Chris, and Jamil Zainasheff. Yeast: The Practical Guide to Beer Fermentation. Boulder, CO: Brewers Publications, 2010. 139-44. Print.

The remaining growth factors are based on an empirical study done by Chris White, which is detailed in:
White, Chris, and Jamil Zainasheff. Yeast: The Practical Guide to Beer Fermentation. Boulder, CO: Brewers Publications, 2010. 139-44. Print.
This model is based on an inoculation rate leading to a yeast growth factor. We approximated results from that study and fitted it to an equation provided below. There are some caveats to the model to be aware of.

The maximum growth factor is 6 (the starter will never grow past that amount).

The saturation point for a starter is 200 million cells/ml (the starter not grow at that inoculation rate).

The growth curve is geared for a starter gravity of 1.036 (9 ° P).

The initial study did not address stir plates or shaking methods. However, anecdotally, aeration and stirring are said to provide positive benefits. We do not have a citation for this unfortunately, but if you can point us towards one we would be happy to update this page and the calculator logic.

As such the only parameters are how big of a starter you're making, and how much yeast you're adding to the starter.
 

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