Is Your Yeast Dead? How To Keep It Alive!

Summary

In this video, Jesse from Still It demonstrates how to test the viability of yeast and offers practical tips for storing it to maximize longevity. He tests four yeast samples of varying ages and conditions, showing how to observe rehydration, foam, and sediment to determine if the yeast is still active or dead. Jesse also explains proper storage techniques—keeping yeast airtight and refrigerated—and offers guidelines on when to use more yeast in recipes if it’s older. The video is an informative, hands-on guide for brewers looking to ensure their yeast remains healthy and effective for fermentation.

Takeaways

• 😀 Testing yeast viability is easy: add yeast to water, observe for rehydration and froth to determine if it's active.
• 😀 Yeast should be stored in an airtight container, preferably in the fridge, to prolong its shelf life.
• 😀 Exposure to heat and moisture is the main enemy of yeast, affecting its ability to stay viable.
• 😀 Yeast can still be usable past its expiration date, as long as it has been stored properly and hasn’t been open for too long.
• 😀 The 'mystery yeast' (unlabeled and poorly stored) was completely dead after testing.
• 😀 Yeast that has been opened for more than 6 months should be tested to ensure it’s still viable.
• 😀 Yeast that has been stored properly in the fridge can last up to a year after being opened.
• 😀 Even after a year of storage, if yeast is still somewhat viable, you can use more of it to compensate for any decreased activity.
• 😀 Distiller Max RM yeast showed more sediment, indicating reduced viability but still good enough to use with more yeast.
• 😀 When yeast is no longer viable, discard it and buy fresh yeast for optimal results.
• 😀 The key sign of healthy yeast is a creamy, frothy texture in the water, which indicates active fermentation potential.

Q & A

How can you tell if yeast is still viable?

You can tell if yeast is viable by observing its rehydration in warm water. If it fluffs up, becomes creamy, and forms foam, it’s still active. If it sinks and forms clumps without any movement, it’s likely dead.

What’s the ideal water temperature for testing yeast?

The ideal water temperature for testing yeast is around 27°C, which is the middle to upper end of its fermentation temperature range.

Does yeast always need to be used before its expiry date?

Not necessarily. While expiry dates are important, the actual viability of yeast depends more on how long the package has been open and how it has been stored.

What storage conditions are best for keeping yeast viable?

To keep yeast viable, it should be stored in a cool, dry place, preferably in the refrigerator. After opening, seal the package in an airtight container or Ziploc bag to protect it from moisture and heat.

How long can opened yeast last in storage?

Opened yeast can last for 6 months to a year if stored properly. After a year, you should consider testing its viability before use.

How can you store yeast after opening it?

After opening yeast, seal it in an airtight container or Ziploc bag and store it in the fridge to preserve its viability.

What does it mean if yeast has a lot of sediment at the bottom of the test glass?

A lot of sediment suggests that the yeast hasn't fully rehydrated or activated, but it doesn't necessarily mean the yeast is dead. It may still be viable but less active.

Can you still use yeast that has been opened for over a year?

Yes, you can still use yeast that has been opened for over a year, but you should test it first. If it’s still somewhat viable, you might need to use more yeast than the recipe calls for.

What should you do if yeast shows minimal activity during the test?

If yeast shows minimal activity, it’s best to pitch more yeast than the recipe calls for. If it still doesn’t activate, it’s probably best to discard it and buy fresh yeast.

What should you do if the yeast test shows no activity at all?

If there’s no activity at all, the yeast is most likely dead and should be discarded. You could attempt to revive it with a starter culture, but it's generally not worth the effort unless it's essential.