Stepping up a yeast starter is useful in homebrewing if you need to make a big starter with a limited container size. Instead of making one huge starter in a large volume of wort, you can go in steps with smaller volumes to reach the right amount of cells.
This video shows the starter volumes and yeast quantities that you need to do stepped starters. I recreated part of a table from the book Yeast, by Jamil Zainascheff and Chris White. You should pick up a copy because it shows you how yeast can improve your beer, and unlike questionable advice based on theory, it’s based on real life experiments. We’re talking lab coats and microscopes people.
Stepped Yeast Starter Resources for Homebrewers
These two BillyBrew posts should be read before watching this video:
Here is the book Yeast by Jamil Zainascheff and Chris White. It’s really great.
And here is the table that I recreated from the book, published with Jamil’s permission:
Please note that this study was done with no added oxygen. Adding oxygen with a stir plate or by shaking will roughly double the amount of growth you get. Also keep in mind that fresh yeast was used in the study, so if your yeast is older then you won’t get as much growth.
To find the maximum size starter you can make with a given container size, read the last number in that column. For example, the maximum starter size you can make in a 2L starter is 300 billion cells (with no aeration).
Any question/comments about stepping up starters? Is that the most exciting PowerPoint presentation you’ve ever seen?