How to Make a Yeast Starter With Washed Yeast

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how to make a yeast starter with washed yeastKnowing how to make a yeast starter is an extremely important process for every homebrewer to know. Yeast starters are essential when making high ABV beers and can save you a lot of money while doing your favorite hobby. In this tutorial, we’re making a yeast starter so we can reuse wild yeast that we harvested, washed, and saved. Make sure to read our previous article about How To Harvest and Wash Yeast if you’re curious how to do that.

Full Video Tutorial

Here is a video tutorial that illustrates the steps listed below

Items Needed

  • Erlenmeyer Flask
  • Dry Malt Extract
  • Star San or similar food-grade sanitizer
  • Washed or packaged yeast
  • Funnel
  • Tin Foil - or similar product that can be used to cover the opening of an Erlenmeyer Flask
  • Stir Plate - not required but good to have

Follow These Steps

1. Start with 2 liters of water in a pot

putting 2 liters of water into a pot on a hot plate

2. Weigh out 200 grams of Dry Malt Extract and stir it in with the 2 liters of water

weighing out dry malt extract

pouring dry malt extract into water

Stir the solution well to ensure that all your DME is incorporated and that nothing will be scorched on the bottom

3. Place your pot on a stovetop and boil it for 10 -15 minutes

dry malt extract boiling

A low boil will be sufficient

4. After boiling, pour the contents of your pot into an Erlenmeyer flask using a funnel - make sure the flask and funnel have been sanitized with Star San

pouring dry malt extract solution into an erlenmeyer flask

pouring dry malt extract solution into erlenmeyer flask

5. Cover the flask with sanitized tin foil and place it in a tub of cold water to cool your solution down to 70° F (21.1° C) - we just filled our kitchen sink up and cooled it down there

cooling erlenmeyer flask filled with dry malt extract solution down using a sink filled with cold water

Liquid crystal thermometer on the side of an erlenmeyer flask indicating that it is at 70 degrees Fahrenheit

We use a liquid crystal thermometer to measure the temperature of our flask

6. Once your flask is cooled, take your washed yeast and decant most of the liquid off of the top. Leave about ¼ of the liquid behind - if you’re making a starter out of packaged yeast, skip steps 6-9 and just put your yeast into the flask

jar with a thin layer of harvested yeast on the bottom and liquid on top

The thin white layer on the bottom is the yeast we want to use

Decanting jar of washed yeast

Make sure not to disturb your washed yeast while decanting - keep it settled on the bottom

liquid amount left in jar after decanting

7. Swirl your jar around in order to incorporate all the settled yeast into the remaining liquid - make sure nothing is stuck to the bottom

8. Place your flask onto a stir plate and insert a stir bar

erlenmeyer flask filled with dry malt extract solution on a stir plate

person holding the stir bar in their hand

Make sure your stir bar is sanitized - just like everything else

9. Pour the contents of your jar into the flask, turn the stir plate on, and wait 36 - 48 hours. If you do not have a stir plate, shake your flask well after pitching the yeast in order to aerate it

pouring decanted jar of yeast into erlenmeyer flask on stir plate

yeast starter after being on the stir plate for 36 hours

10. After 36-48 hours your yeast starter will be ready to pitch - watch us use it in the brew day video below

How to Make a Beer by Harvesting Yeast From an Old Batch

Portrait of Kyle Brown

Kyle Brown is the owner of Clawhammer Supply, a small scale distillation and brewing equipment company which he founded in 2009. His passion is teaching people about the many uses of distillation equipment as well as how to make beer at home. When he isn't brewing beer or writing about it, you can find him at his local gym or on the running trail.

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