Yeast Starter from Wort?

[timcadieux]

So there are lots of calculators or tutorials on how to use dme to make a yeast starter but I kept some extra wort after my last batch and would like to use that.

Anyway to calculate how to build a 2L batch using 2 small mason jars worth of 1.058 wort?

 

[billl]

Just dilute with water until you get to slightly under 1.040, then boil to sanitize. You won't necessarily get 2 liters though. You would need 1.4 liters of 58 point wort to make 2 liters of 40 point.

The formula to find out how much starter you can make is (liters wort)x (points wort)/40

 

[VikingChrisColby]

Use the "concentration times volume" (C1V1 = C2V2) equation to calculate the dilution rate. For example, if you wanted to make 3 quarts of yeast starter at SG 1.020, and your saved wort is SG 1.058, you would set the equation up this way:

20(3) = 58(X)

Solving for X would give you 1.03. In other words, you would need a just a hair over a quart of wort at SG 1.058 to make 3 quarts of wort at SG 1.020.

You can use any units for concentration and volume, as long as you use the same units on both sides of the equation. If you use specific gravity for concentration, use only the numbers after the decimal point. (As in the example above, SG 1.058 become "58" for the equation.)


Chris Colby
Editor
http://beerandwinejournal.com/

 

[catdaddy66]

Thank you, Chris! I'll be using this from here on out.


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