Creating the Perfect Starter

Category : Technical
Date : March 16, 2021
Author : White Labs Technical Team

A starter is a great method when looking to increase your pitching rate. The process is essentially creating a small beer and harvesting the yeast to pitch to the next batch. Deciding on making a starter comes with a lot of questions like how big should it be, how much yeast do I add, and do I use a stir plate? There are many pros and cons to making a starter, so here we would like to answer the top questions when it comes to yeast starters.

What is a starter? 

A yeast starter is a common homebrewing term for the process of propagating additional cells from a culture of yeast. This is typically done by sterilizing malt extract in a flask or other sanitary container and growing the yeast before adding it to a fermentation. 

What size starter should I make? 

Many recipes call for a 1L starter, but we actually recommend using at minimum a 2L starter. As a general rule of thumb, the larger the starter, the more yeast growth you’ll achieve. This will allow the yeast the most nutrients and sugar to grow more cells. Note, that White Labs yeast is sold in pitchable quantities and while a starter can be beneficial, it is not required. See our pitch rate calculator for pitch rate suggestions.

How much yeast do I use?

We recommend that you use 1 homebrew PurePitch per 2L-3L starter. If you add more yeast per liter of starter, the yeast will need to share those nutrients and fewer new cells will be created. 

Should I use a stir plate? 

We highly recommend using a stir plate for starters. The stirring provides oxygen, but also provide a way for the yeast to be in contact with sugar and nutrients. We see a significant decrease in the time needed for a starter when this method is used. 

How long will my starter take? 

When using a stir plate, 24-48 hours is generally enough time for a starter to be completed. If the starter sits ambient on a counter, 48-72 hours is suggested under similar parameters as our suggested starter recipe. 

Recipe suggestions for a starter  

Below is an example starter recipe. The recipe can be scaled or changed to materials.
Materials:  Instructions:
  1. Add 1.5L of water to the flask
  2. Add 200g of DME or LME
  3. Top flask with water to 2L mark 
  4. Add ⅛ teaspoon of preferred yeast nutrient
  5. Add antifoam (Optional) 
  6. Cover opening with foil and boil for 15min 
  7. Allow the flask to cool to room temperatures and aseptically transfer yeast to liquid
  8. Swirl and place on stir plate or countertop based on the method of fermentation