Mr Malty Production date

[Bert1097]

Guys,

I have a question about the production date on Mr Malty's yeast calculator.

First, to tell you my process so my question is clearer. I start w/ a smack pack of wyeast and pitch that into a 4L stir plate starter and allow fermentation to finish out. While making the starter I also sterilize 6 little mason jars in my pressure cooker, seal them and put them away.

I decant the starter once everything is settled and then pitch the slurry into the previously sterilized mason jars, screw the lids on and place in the fridge to make starters at a later date.

Now my question. Do I use the date that I dumped the slurries into the mason jars or do I use the original date on the smack pack?

Thanks in advance for any comments.

 

[afr0byte]

If you put the correct production date in originally, when you were determining the number of yeast you'd grow with the starter, I'd that you should put the date that you decanted as the production date. However, I'd imagine that the yeast in your mason jars are going to lose viability faster, much like yeast slurry harvested from a fermenter because you're not going to be able to handle the yeast as well as White Labs or Wyeast.

 

[luke2080]

Yeah - I would have used the production date of the original smack pack to determine that viability. Then use Mr. Malty's calculations with your starter size, to see how much yeast cells you are expected to have after your big starter. This gives you an idea of the yeast cell percentage in the slurry once you have decanted the wort.

After that, when you are going to use it, use the pitch date (or really the day after) as your new production date for your yeast slurry. I believe the calculator handles viability differently for slurry and production packs/vials.

 

[Bert1097]

Thanks guys!