Starter - Package Date for WLP

[x3la]

WLP just give a "Best By" date on their PurePitch packs. MFG date is not present. The Viability calculation and consequently the Starter Size calculations aren't really useable.

I'm guessing that it was packaged 4 months before the "Best By" based on the information on their website:

https://www.whitelabs.com/faq/purepitch/purepitch-shelf-life

Could this perhaps be a hover tip/note/extra field?

[BOB357]

I believe you're right about the PurePitch. The primary reason BeerSmith, and other brewing software to my knowledge, doesn't make note of these things is that they vary from manufacturer to manufacturer, and may change. If you use the inventory feature you can enter the Mfg. date when you put a packet into inventory and it will carry over to the yeast starter tool.

[Oginme]

One of the issues with technology progress is that it makes things obsolete.  According to White Labs, they switched from the manufacturing date to a best before date because their new packaging will give them that long of a shelf life such that you will still have around the 100 billion viable cells (actual numbers from their web site is 110 billion to 80 billion) at the date listed on the package.  This throws out all the viability loss curves in the yeast starter calculators which are being used at present and are based upon manufacturing date.

Having no access to White Labs yeasts locally in the past couple of years, I have not had the opportunity to take a couple of packs and perform a cell count to verify their stance.

[x3la]

By entering Lot: 1082224 and "Homebrew Pitch" here: https://classic.yeastman.com/Login/Public/Report/PublicLabQCResult.aspx it shows "QC Release Date:  2/9/2020" - presumably that's just after the MFG date.

[Oginme]

For most companies that would be the manufacture date.  It is not complete until released from QC hold.