Wyeast Nutrient shelf life

[bgmac]

I have a tube of WYeast nutrient with a mfg date of May 2018. It has been stored in the fridge since I received in 2018. Is this past its service life?

 

[RPh_Guy]

Nope

 

[bgmac]

Does it really have a shelf life?

 

[Robert65]

They put a manufacturing date and lot no. on it, but no expiration date. I haven't looked to see if their website gives information on shelf life and storage instructions. But it's made of minerals, nitrogen compounds, and dead yeast. I don't imagine any of those degrade very quickly if at all.

 

[Vale71]

The worst thing that can happen is it turns into a block of chalk because it absorbs moisture. Just grind it up again and use it with no concern, despite the name there are no actual nutrients (i.e. sugars) in it so nothing undesirable can grow in there.

 

[ESBrewer]

I think zinc ions and certain amino acids are probably the most useful additional nutrients for beer production using malt based wort. Zinc ions probably last forever in the fridge, but amino acids have some sort of half life. Reagent grade valine (that can reduce diacetyl according to some studies) seems to have half life of a couple of years so there will be a good bunch of active valine even after five years of storage. However, Wyeast pages say: "Stability 1 year if stored in airtight container in a cool environment." I would still use it after two-three years if stored dry and in cool environment. Anyway, it gets boiled so the microbes that could interfere with beer get eliminated and the only downside that you are likely to see will be the slightly dimished activity of the product. After three years I would replace it with a new vial because it's so affordable.

 

[bgmac]

I think zinc ions and certain amino acids are probably the most useful additional nutrients for beer production using malt based wort. Zinc ions probably last forever in the fridge, but amino acids have some sort of half life. Reagent grade valine (that can reduce diacetyl according to some studies) seems to have half life of a couple of years so there will be a good bunch of active valine even after five years of storage. However, Wyeast pages say: "Stability 1 year if stored in airtight container in a cool environment." I would still use it after two-three years if stored dry and in cool environment. Anyway, it gets boiled so the microbes that could interfere with beer get eliminated and the only downside that you are likely to see will be the slightly dimished activity of the product. After three years I would replace it with a new vial because it's so affordable.

Thanks for the detailed post. I will be using it on brew day this weekend.

 

[dmtaylor]

It should last for a million years.