<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>

CC BY-SA 3.0
2017-03-25T14:06:20.473Z
Awesome, thanks for the reply! Any thoughts re: the statement on visible yeast particulates?
amagnasco
CC BY-SA 3.0
2017-03-25T17:45:05.293Z
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'.
Mr_road
CC BY-SA 3.0
2017-03-25T20:03:57.767Z
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!
amagnasco
CC BY-SA 3.0
2017-03-27T15:31:42.730Z
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.
PoloHoleSet
CC BY-SA 3.0
2017-03-25T10:09:56.030Z
2017-03-25T10:09:56.030Z
Mr_road
<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>

<storage><aging><yeast>
Does beer expiration change based on yeasts?
amagnasco
# 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


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## 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.  

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