Wyeast best by date

[private4587]

bought a wyeast 1469 but instead of MFG date it now has a best by date. as i want to overbuild this yeast to keep some for next brew anyone know how to do this. The yeast build software i use has the option for mfg date to workout viability so how do i enter this using best by date?the date in question is 09/21 Wyeast say use within 6months but cannot except this as mfg date as this would mean yeast not being made yet!

 

[trueblue]

Fairly sure I read somewhere the MFG date is 4 months before use by date. I used this criteria to overbuild some 1275 Thames Valley and brewed with a 3rd generation a few days back and it was trying to escape from the FV the next day.

 

[foxbat]

Fairly sure I read somewhere the MFG date is 4 months before use by date. I used this criteria to overbuild some 1275 Thames Valley and brewed with a 3rd generation a few days back and it was trying to escape from the FV the next day.

I think the 4 month figure is for the white labs vials with the pure-pitch plastic packs being 6 months.

Wyeast switched about a year ago from quoting MFG date to best before date and the best I can find from the US sites is that's 6 months. Not 100% certain though.

 

[samale]

I work on 6 months as well. I think I heard it on the forum

 

[crescent city Mike]

If you plan on yeast farming, make the small investment and purchase/build a stir plate. I've brought back yeast packs that were over a year old. Of course they were properly refrigerated all that time. A stir plate can turn that smack pack into about 4 times the yeast it will make on its own.