Came across a very interesting blog post on the topic of smack pack cell counts. http://breweveryday.com/fresh-yeast-cell-count/ The short version is that a nearly 2 month old smack pack came in at a cell count of over 170 billion viable cells, according to this guy. I have no idea if his counting method is sound, but I was inspired by a recent old smack pack incident to dig around for these numbers; I seem to recall seeing elsewhere an estimate that a fresh smack pack has somewhere in the neighborhood of 160 billion viable yeast cells. Wyeast on their website warranties their 100 billion cells being viable for up to 6 months from the date of manufacture, so it seems very likely that the packs ship with well over 100 billion viable cells. Perhaps twice that number or even more, if this guy's count is accurate.
Just from a business perspective...if they guarantee 100B cells, but are actually packaging twice as many. Then they have a poor business model...because they've cut their potential revenue in half.
I think 6 months of shelf life versus a week or two at the listed cell count makes selling yeast a lot more economically viable.
https://www.wyeastlab.com/rw_advantage.cfm It's not specific, but they clearly state there is a 6 month from manufacture date product warranty, and that the minimum cell count is 100 billion. Perhaps that doesn't actually mean 100 billion viable cells, but that's how I take it.
More info: https://www.wyeastlab.com/hb_productdetail.cfm?ProductID=16 If they aren't guaranteeing enough viable cells with which to inoculate wort at their listed rates, then what are the my guaranteeing?
I highly encourage everyone to count their cells and demand a refund when the number of cells is less than 100 billion!
Well if nothing else this has finally convinced me that these forums are worthless. Brilliant thoughts everyone, bravo!
I personally do not count yeast but based upon my readings, Matthews Murray is following the proper procedures. I have exchanged information with @mattbk where he expressed his opinions on the error bars associated with yeast counting. If my memory serves me correctly he opined that for a trained individual that yeast counts would provide a value with an error bar of ± 10%. So for the particular example of Mathew Murray the value would be 172 billion ± 10% or expressed as a range: 154.8 – 189.2 billion cells. This is assuming that Mathew Murray can yeast cell count properly. There was an article by Chris Colby in the Jan/Feb 2006 BYO which stated: “Wyeast’s 125 mL Activator packs are advertised to contain 100 billion cells, but actually average around 120–130 billion cells, according to Les Perkins, microbiologist and quality control manager for Wyeast.” http://byo.com/yeast/item/1487-the-latest-on-liquid-yeast Cheers!
Are you reducing your pitch rate based on one guy counting one pack of yeast? What are we supposed to conclude from this information? What sort of responses where you looking for? In other words, how can we validate the usefulness of your topic and make you feel this forum is more than worthless?
"Our Product Warranty states that we guarantee the viability of the yeast in our Activator™ packages for 6 months from the manufacture date assuming that they have been properly shipped, stored and handled." Note that there are no numbers in the guarantee itself. I take it to mean they guarantee that there are viable yeast. I'd be very interested to read any claim by Wyeast that their smack packs start off with over 170B cells.
