Yeast Viability

[SmuggledBudgie]

Hi all,

I'm making an Irish Red (OG1.054/vol 22L) using liquid yeast with a manufacturing date of 8 March 2016.

In BS2 in the recipe tab after entering the above date it says my viability is 96%. if I use the Yeast Starter Tool, for the same date, it gives me a viability of 50%. As a comparison, Mr Malty is estimating 38%. I haven't changed the settings in BS2, Liquid Age Rate is set to 21%.

Wondering if someone could help shine some light on why these are so different and which one to use.

 

[Black n Tan]

In BS you must have the date for the recipe set incorrectly: a three month old packet does not have 96% viability.

 

[mstrelan]

It's because you're on a mac

 

[mstrelan]

Maybe you're set up to use American date format and it thinks your yeast is manufactured in August.

 

[Danscraftbeer]

I've never had bought yeast at 96% viability. :unsure: checking notes now, recycled fresh yeast cake maybe? No. Must be a typo.

 

[SmuggledBudgie]

Thanks,

Black n Tan your suggestion has fixed the problem. The date on the design page of the recipe was set to 21/1/16 from the last time I made it. Interesting, I hadn't noticed that connection before, I just assumed the viability calc would have just used today's date. It looks like the Yeast Tool does, but starter tab doesn't.

Cheers.