[Richard]

The new liquid yeast packages have higher cell counts, perhaps higher than necessary, when they are fresh from the factory. By the time a homebrewer gets around to pitching that yeast there will  be fewer viable cells. Without the capacity to stain and count cells, there is really no way to tell the health and viability of a package of yeast. I purchase liquid yeast from a store that I know has a good distribution chain that keeps the yeast refrigerated at all times, so that helps. The most popular strains are purchased and re-stocked frequently, while less popular strains might sit around for months. I recently purchased 2 of the new White Labs pouches and one of them was packaged in January.  If the pouch was only 2 months old I would just pitch it directly, but I decided that for a mid-June brew I needed to make a starter. Then I know that the revitalized yeast will be healthy, but I will pitch only part of the starter to make sure I am not overpitching.

[Megary]

My concern as a 3 gallon brewer is simply whether or not I should be pitching a full 11g pack of dry yeast or should I stick to the Mfg’s pitch rate calculator.  Almost always I am overpitching, but does it affect the finished beer? 

That was the question I sent to Lallemand earlier today.  Hopefully I’ll get a reply.

[BrewBama]

If you’re using the Lallemand calculator and inputting volume, gravity, and temp, then the calculator shouldn’t be recommending an over pitch.

[fredthecat]

My concern as a 3 gallon brewer is simply whether or not I should be pitching a full 11g pack of dry yeast or should I stick to the Mfg’s pitch rate calculator.  Almost always I am overpitching, but does it affect the finished beer? 

That was the question I sent to Lallemand earlier today.  Hopefully I’ll get a reply.

based on using that lallemand calculator, for brews this year and retroactively checking beers that had imho yeast related issues. i think it is an accurate tool. simply having this tool, let alone having some imho better strains than fermentis has solidified lallemand as my go to dry yeast choice. i DID contact fermentis about if they were working on or had a yeast pitch calculator and they never replied to me.

also @megary, yeast "harvesting imho is incredibly simple. i usually do 2 or 3 beers off of a yeast i choose and simply take the yeast left on the bottom and put it in a 1 gallon glass carboy i habe, sanitized and then add that directly to the wort anywhere from that day up to 10 days later. it has never, ever been an issue.

[Village Taphouse]

also @megary, yeast "harvesting imho is incredibly simple.

Yeah, I have been harvesting yeast for as long as I've been brewing.  I'm very careful with sanitation and I just pitched 2124 into a SEVENTH batch this spring!   

[Megary]

If you’re using the Lallemand calculator and inputting volume, gravity, and temp, then the calculator shouldn’t be recommending an over pitch.

Indeed.
But I always pitch a full pack regardless what the calculator says. That’s my concern…I’m over pitching on most beers, sometimes by 5g.

[tommymorris]

If you’re using the Lallemand calculator and inputting volume, gravity, and temp, then the calculator shouldn’t be recommending an over pitch.

Indeed.
But I always pitch a full pack regardless what the calculator says. That’s my concern…I’m over pitching on most beers, sometimes by 5g.

Have you tried following the calculator’s recommendations to see if you can taste a difference?

[ynotbrusum]

also @megary, yeast "harvesting imho is incredibly simple.

Yeah, I have been harvesting yeast for as long as I've been brewing.  I'm very careful with sanitation and I just pitched 2124 into a SEVENTH batch this spring!   

Just for a point of reference I took a lager yeast out 25 re-pitches over about 2 years, until I felt I shouldn't push it much further and frankly wanted to try a different yeast variety...the yeast held up admirably (WLP 800) fwiw.  Good O2 and yeast nutrient kept it running smoothly.

[Village Taphouse]

also @megary, yeast "harvesting imho is incredibly simple.

Yeah, I have been harvesting yeast for as long as I've been brewing.  I'm very careful with sanitation and I just pitched 2124 into a SEVENTH batch this spring!   

Just for a point of reference I took a lager yeast out 25 re-pitches over about 2 years, until I felt I shouldn't push it much further and frankly wanted to try a different yeast variety...the yeast held up admirably (WLP 800) fwiw.  Good O2 and yeast nutrient kept it running smoothly.

I like to get a yeast up and running and then use it in subsequent batches without actually 'storing' it.  So it's in the fermenter, I transfer and save the yeast in a sanitized flask and it's in the fridge for a VERY short time... like a day or two and then it gets repitched.  I take a small sample from that prior batch just to make sure everything seems okay.  Occasionally I might pick up an unusual flavor or aroma and wonder if I should repitch.  This 2124 is working now in a gold lager and then it's going one more round in a sort of Vienna Lager and then its jersey will be retired and it's on to Novalager. 

[Megary]

If you’re using the Lallemand calculator and inputting volume, gravity, and temp, then the calculator shouldn’t be recommending an over pitch.

Indeed.
But I always pitch a full pack regardless what the calculator says. That’s my concern…I’m over pitching on most beers, sometimes by 5g.

Have you tried following the calculator’s recommendations to see if you can taste a difference?

Nope, not once.   

I suppose I’ll have to try it at some point.  I use BRY-97 a lot and I’m not sure that’s the yeast that will really show a difference.  I mean, it’s not a very expressive yeast.

[Semper Sitientem]

If you’re using the Lallemand calculator and inputting volume, gravity, and temp, then the calculator shouldn’t be recommending an over pitch.

Indeed.
But I always pitch a full pack regardless what the calculator says. That’s my concern…I’m over pitching on most beers, sometimes by 5g.

As a 3 gallon brewer myself and someone who uses dry yeast exclusively, I determined some time ago through trial and error that 2/3 of a packet (7.3 grams or 7.6 grams for Fermentis) for my standard ABV beers was the right amount. I vacuum seal any remainder.  This SOP eliminates the yeast pitch issue for me.

[Megary]

If you’re using the Lallemand calculator and inputting volume, gravity, and temp, then the calculator shouldn’t be recommending an over pitch.

Indeed.
But I always pitch a full pack regardless what the calculator says. That’s my concern…I’m over pitching on most beers, sometimes by 5g.

As a 3 gallon brewer myself and someone who uses dry yeast exclusively, I determined some time ago through trial and error that 2/3 of a packet (7.3 grams or 7.6 grams for Fermentis) for my standard ABV beers was the right amount. I vacuum seal any remainder.  This SOP eliminates the yeast pitch issue for me.

Thanks for that.

For clarification, assuming a standard beer, is that what is needed for a proper fermentation or is that the amount that gives you the best yeast character?  Maybe both…

But, I use BRY-97 a lot and since it’s so clean, I question whether it matters if I pitch right to the cell or overpitch by a mile.  It’s likely to be clean regardless.  Now if I’m using London, or S-04, or Munich….pitch rates might matter a whole lot more??

[tommymorris]

If you’re using the Lallemand calculator and inputting volume, gravity, and temp, then the calculator shouldn’t be recommending an over pitch.

Indeed.
But I always pitch a full pack regardless what the calculator says. That’s my concern…I’m over pitching on most beers, sometimes by 5g.

As a 3 gallon brewer myself and someone who uses dry yeast exclusively, I determined some time ago through trial and error that 2/3 of a packet (7.3 grams or 7.6 grams for Fermentis) for my standard ABV beers was the right amount. I vacuum seal any remainder.  This SOP eliminates the yeast pitch issue for me.

Thanks for that.

For clarification, assuming a standard beer, is that what is needed for a proper fermentation or is that the amount that gives you the best yeast character?  Maybe both…

But, I use BRY-97 a lot and since it’s so clean, I question whether it matters if I pitch right to the cell or overpitch by a mile.  It’s likely to be clean regardless.  Now if I’m using London, or S-04, or Munich….pitch rates might matter a whole lot more??

Personally, I don’t think it makes a difference. I brew 3 gallon batches exclusively. I always pitch a full packet of dry yeast. I use Bry-97, Verdant, S-04, Diamond, 34/70, Novalager. All seem great to me.

I have used Windsor, London, Nottingham also. I don’t think I am missing any yeast character.

PS. I typically use a packet for 3 batches; pitch dry yeast once and then use the slurry twice.  That keeps the cost very low.  After three batches I am usually ready to move on to a different yeast.  I usually brew lager, ale, lager, ale… So, I have two yeasts active at a time.

[denny]

I just ran across this regarding pitch rate and overpitching. Hope it's useful ....20+ years ago, the late Homebrew Digest did their Fornite of Yeast, where Dr. Clayton Cone of Lallemand answered questions.  Even back then, I was thinking about pitch rate., so I asked the following...

Date: Thu, 21 Aug 2003 21:00:15 -0500
From: "Rob Moline" <jethrogump at mchsi.com>
Subject: Dr. Cone Responds- Yeast Flavours- Denny Conn

         Dr. Cone Responds- Yeast Flavours- Denny Conn

Dr. Cone,
   First, thank you so much for giving us some of your time.

   My question concerns yeast growth as it relates to flavors in beer.  I have read several articles mentioning that yeast growth is important to flavor production in beer, and that the amount of yeast growth is related to the amount of yeast pitched.  My own completely unscientific experiments have lead  me to believe that I produce more "interesting' beers when I, for instance, repitch only part of the yeast slurry from a previous batch rather than the entire amount.  The conventional wisdom in the homebrew world seems to be to use the entire previous slurry to produce short lag times.  Is there a relationship between yeast growth and the flavors produced in beer?  Is it better to pitch an entire previous yeast slurry, or is there a benefit to using a large, but not entire, amount of slurry?  I apologize for the vagueness of the question, but I have no way to quantify the exact amounts I've been using.  It's simply either "all" or "part".
   Thank you again.
Denny Conn


Denny Conn,
   Ester and other flavor component production or synthesis is a complex subject because there are so many variables taking place at the same time.   You are right, ester production is related to yeast growth but not in the way you might think. The key element to yeast growth and ester production is acyl Co-A. It is necessary for both yeast growth and ester production.  When it is busy with yeast growth, during the early part of the fermentation, it is not available for ester production.  Ester production is directly related to biomass production. Everything that increases biomass production (intensive aeration, sufficient amount of unsaturated fatty acids, stirring) decreases ester production. The more biomass that is produced the more Co-enzyme A is used and therefore not available for ester production. Anything that inhibits or slows down yeast growth usually causes an increase in ester production: low nutrient, low O2.  It has been noted that a drop in available O2 from 8 ppm down to 3 ppm can cause a four fold increase in esters.
   
Stirring in normal gravity decreases ester production. Stirring in high gravity increases ester production. CO2 pressure in early fermentation decreases ester production.  Taller fermenters produce less esters than short fermenters. High temperature early in fermentation decreases ester production.  High temperature later in fermentation increases ester production. Low pitching rate can result in less esters.
   
There are other flavor components such as higher alcohol that have there own set of variables. Stirring increases production of higher alcohols.  CO2 pressure does not effect the production of alcohol. Amino acid levels in the wort effect the production of higher alcohols.  Most of the higher alcohol is produced during the growth phase (exponential phase) of the yeast.    I am sure that there are many other variables.  I am also sure that there are beer makers that have experienced the very opposite with each of the variables.

   Pitching rates depend on several factors:
   (1) The speed in which you wish the fermentation to take place.  Some professional brew master are in more of a hurry than others; desired beer style, shortage of fermenter space.  Pitching rates would vary as a means to increase or decrease the total fermentation time. 10 X 10/6th cell population for normal fermentation rates.  20 X 10/6th or more for a quick turn around.
   (2) Temperature control.  If lack of refrigeration is a problem, the fermentation needs to be spread out over a longer period  by pitching with less yeast.
   (3) Health of the pitching yeast. If the pitching yeast has not been stored under ideal conditions (4C for less than one week) then larger pitching rate must be done to compensate for the deteriorate of the yeast.  Increased pitching rates has its limits in trying to compensate for poor storage conditions.
   (4) When all other variables are under control you can use variations in pitching rates to achieve certain flavor profile that are of interest to you.
   
Conventional wisdom regarding pitching rate can lead to problems.  During each fermentation cycle the yeast will increase in size about three times, so if you use all the yeast from the previous batch you will soon be pitching with a huge amount of yeast.  Professional brewers usually re-pitch with about 25% of the yeast from the previous batch.  Proper handling of the yeast during storage (4C and <7 days) will minimize any problem with long lag phase. Start with a fresh culture of yeast after about five recycles for bacteria control and or after 10 - 15 cycles for genetic drift purposes.
   
There are many who will say that they are proud of the fact that they have used the same yeast after over 100 cycles.  More power to them. I wish that I could explain their luck. Good practices suggest frequent renewal with a fresh culture is a good policy.
   Thank you for your very good question.

Clayton Cone
- ---

[Richard]

Wow, you not only saved a message from 20 years ago, you were able to locate it. I'm impressed!

There is a lot of information there, and I'm going to have to think about it a bit.