It happens to everyone who stocks liquid yeast products.. sometimes a few strains are still on hand past the recommended "best before" date and then the question of what to do with them comes up.
We could simply toss them out, then no one gains anything and it is a total waste.
Or, we could find a way to encourage people to build up this depleted (not dead, just depleted) yeast and either store it or use it in an upcoming batch, and this is what we have decided to do.
Here is how it works
When we identify expired yeast in the fridge, we will move it out of normal stock, into expired stock, and relabel it.
Depending on the amount of time past the best before date, the price will drop in 2 steps: first, we will mark it down 50%, then it will be marked down 75%. If there are no takers after a few days at 75%, it will be discarded.
Each expired pitch of yeast will come with 200 grams of Pilsen Light DME to help offset the cost of making a starter.If you are new to making starters, please follow the instructions and links below to learn this simple and valuable practice. Unless you are brand new to brewing and still working on other basic processes, you should be considering starters from both an economical and proper pitch perspective.
Our goal is to keep from having to throw yeast away, so while this costs us some time and materials, we hope it will encourage a few people to look at expired yeast differently. With a little TLC, it is easy to bring old yeast back to very pitchable quality.
Follow this link to the Expired Yeast
The Steps to Make a Yeast Starter
The following are general instructions that can be applied to all sizes of starter:
Determine the appropriate starter volume to achieve the target number of viable yeast cells for your beer. Remember, you can use an online yeast calculators to quickly determine these variables. Here are links to a couple of popular calculators; BrewUnited BrewersFriend YeastCalc
Weigh out 1 gram of dry malt extract for every 10 milliliters of target starter volume.
Add the dry malt extract to the vessel you will be boiling in, such as an Erlenmeyer flask.
Add enough water to the boil vessel (dry malt already added) to reach the target starter volume.
Add about 1/4 teaspoon of yeast nutrient to the boil vessel. You can use slight less for starters under 1-2 L and slightly more for ones larger.
Bring to a gentle boil for about 15 minutes. Keep the boil vessel covered to maintain as much of the volume as possible.
After 15 minutes, allow the wort to cool.
If needed, transfer the liquid to the vessel that will hold the starter. (Note: As with beer, anything that comes into contact with the starter wort post-boil should be properly clean and sanitized).
Pitch yeast into the chilled starter wort.
Use a stir plate or intermittent shaking to add vital oxygen to the starter.
Pitch into beer once ready, or store in the fridge until needed.
Starters are typically either pitched during high krausen or after active fermentation has subsided.
Pitching at high krausen, or at the height of the starter fermentation’s activity, which typically is 12-18 hours after pitching the yeast into the starter is the most convenient method. Simply pitch the entire contents of the starter into the wort of your homebrew once it’s ready.
Be sure the temperature is within 5-15°F of the wort’s temperature when using this method. If it’s too hot or too cold, it can shock the yeast and ultimately create problem fermentations.
Warm starters or starters with volumes more than 5% of the main batch volume need additional preparation. First, allow the fermentation to basically complete and then chill the starter by placing it in the fridge until it is near the temperature of the wort it is intended for. Decant the liquid and pitch only the yeast cake.
That’s it! You just pitched the perfect amount of yeast in your homebrew.