Answers.Body: <p>Quick answer no. The yeast used should have very little effect on on the expiry date. Things that will affect this more are:</p>
  
  <ul>
  <li>Temperature of fermentation</li>
  <li>Hot side aeration</li>
  <li>Cold side aeration</li>
  <li>Pasteurization</li>
  <li>Filtration</li>
  <li>Colour of bottle the beer is stored in</li>
  <li>Type of beer ie % dark malts</li>
  <li>Live product vs sterile filtered</li>
  </ul>
  
  <p>This list is incomplete. This is an incredibly complex subject, there are PhDs in Brewing/Chemistry handed out for small aspects of each of these topics.</p>
  
  <p>Here is a quick overview presentation of the technical aspects surrounding beer stability and stabilisation. </p>
  
  <p><a href="https://www.craftbrewersconference.com/wp-content/uploads/2015_presentations/F1420_Deniz_Bilge.pdf" rel="noreferrer">https://www.craftbrewersconference.com/wp-content/uploads/2015_presentations/F1420_Deniz_Bilge.pdf</a></p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-03-25T14:06:20.473Z
Answers.Text: Awesome, thanks for the reply! Any thoughts re: the statement on visible yeast particulates?
Answers.UserDisplayName: amagnasco
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-03-25T17:45:05.293Z
Answers.Text: Visibility of yeast particulates have no affect on weather or not the beer is fit for consumption. Some yeasts do not flocculate (clump) in the same way as others, but a hazy or yeasty beer can be delicious and is almost certainly fit for consumption, unless it smells or tastes 'bad'.
Answers.UserDisplayName: Mr_road
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-03-25T20:03:57.767Z
Answers.Text: Thank you so much! That makes a lot more sense to me, particularly given that I know some beers optimize for yeastiness (Hefeweizen). Great answer!
Answers.UserDisplayName: amagnasco
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2017-03-27T15:31:42.730Z
Answers.Text: And some yeasts are naturally "top-fermenting" while others are not. A bottle of beer with yeast in it generally keeps longer and continues to (slightly) change in flavor is it ages.  In regards to the "colour of the bottle" - light/sunlight is the #1 factor is a beer going "skunky."  Clear is the worst, green is also not great. The trendy practice of adding a lime to a Corona started because it was needed to choke down that crappy, cheap, skunky beer.
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Answers.UserDisplayName: Mr_road
Body: <p>Part of my job involves selling beer. I was told by a coworker that visible yeast particulates at the top of a beer bottle indicate that it's not fit for consumption, whereas yeast at the bottom is fine. </p>
  
  <p>Is this true? And if so, does it change depending on whether it's a top-fermenting or bottom-fermenting beer? Does this affect meads and ciders as well? </p>
  
Tags: <storage><aging><yeast>
Title: Does beer expiration change based on yeasts?
UserDisplayName: amagnasco
ThreadText: # Does beer expiration change based on yeasts?
  
  (Asked by: username_0 on 2017-03-17)
  
  Part of my job involves selling beer. I was told by a coworker that visible yeast particulates at the top of a beer bottle indicate that it's not fit for consumption, whereas yeast at the bottom is fine.
  
  Is this true? And if so, does it change depending on whether it's a top-fermenting or bottom-fermenting beer? Does this affect meads and ciders as well?
  
  **Tags:** storage, aging, yeast
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2017-03-25. Score: 4 | Accepted answer
  
  Quick answer no. The yeast used should have very little effect on on the expiry date. Things that will affect this more are:
  
  * Temperature of fermentation
  * Hot side aeration
  * Cold side aeration
  * Pasteurization
  * Filtration
  * Colour of bottle the beer is stored in
  * Type of beer ie % dark malts
  * Live product vs sterile filtered
  
  This list is incomplete. This is an incredibly complex subject, there are PhDs in Brewing/Chemistry handed out for small aspects of each of these topics.
  
  Here is a quick overview presentation of the technical aspects surrounding beer stability and stabilisation.
  
  <https://www.craftbrewersconference.com/wp-content/uploads/2015_presentations/F1420_Deniz_Bilge.pdf>
  
  > **Comments:**
  > **username_0**: Awesome, thanks for the reply! Any thoughts re: the statement on visible yeast particulates?  
  > **username_1**: Visibility of yeast particulates have no affect on weather or not the beer is fit for consumption. Some yeasts do not flocculate (clump) in the same way as others, but a hazy or yeasty beer can be delicious and is almost certainly fit for consumption, unless it smells or tastes 'bad'.  
  > **username_0**: Thank you so much! That makes a lot more sense to me, particularly given that I know some beers optimize for yeastiness (Hefeweizen). Great answer!  
  > **username_2**: And some yeasts are naturally "top-fermenting" while others are not. A bottle of beer with yeast in it generally keeps longer and continues to (slightly) change in flavor is it ages.  In regards to the "colour of the bottle" - light/sunlight is the #1 factor is a beer going "skunky."  Clear is the worst, green is also not great. The trendy practice of adding a lime to a Corona started because it was needed to choke down that crappy, cheap, skunky beer.  
  
  ---
  
  