Sign up for our e-news!

CONTACT US

 

SEARCH SITE

 


Brewers

Recommended Pitch Rates

What is “Pitch Rate”?

The term pitch rate refers to the amount of yeast that is added to cooled wort.  Pitch rate is generally referred to in cells per milliliter.

Do You Know How Much Yeast You Are Pitching?

Consistent and reproducible fermentations are not possible without consistent and adequate pitch rates.  Quantity of yeast added to the fermentor will affect every aspect of your finished product, from attenuation level, to flavor and aroma profile, to clarification.  For home brewers it is difficult to know how much yeast is in the fermenter.

Activator Package:

The Wyeast Activator (125 ml) smack-pack is designed to directly inoculate 5 gallons of standard ale wort (O.G. < 1.060, 65-72°F). When brewing high gravity beer (O.G. >1.060) or cold fermented lagers or ales (<65 °F)) additional yeast will be required. An Activator contains approximately 100 billion cells which will deliver slightly less than 6 million cells per milliliter to a 5 gallon batch of beer.

How Much Yeast Do I Need?

The quantity of yeast needed varies for style of beer and yeast strain to be used.   Original gravity and temperature are both also major factors.  When the original gravity increases, the amount of yeast added also needs to increase (see High Gravity Brewing for more information).  For lagers that are fermenting cold, the pitch rate needs to increase (see Lager Brewing for more information).

The following chart outlines recommended pitch rates based on specific wort and fermentation conditions.  Pitch rates are valid for both direct pitching Wyeast products and for pitching with a starter culture of Wyeast products

Standard Pitching Rates:

 

 STYLE

 GRAVITY

 PITCHING
TEMPERATURE
(°F)

 FERMENTATION
TEMPERATURE
(°F)

 PITCH RATE
(Million Cells/ml.)

Ale

 <1.060 (15P°)

 >65

 >65

 6.00

Ale

 1.061-1.076 (15-19P°)

 >65

 >65

 12.00

Ale

 >1.076 (19P°)

 >65

 >65

 >18.00

Lager*

 <1.060 (15P°)

 >65

<60

 6.00

Lager*

  1.061-1.076 (15-19P°)

 >65

 <60

 12.00

Lager*

 >1.076 (19P°)

 >65

<60

 >18.00

Lager

 <1.060 (15P°)

 <60

 <60

 12.00

Lager

  1.061-1.076 (15-19P°)

 <60

 <60

 18.00

Lager

 >1.076 (19P°)

 <60

 <60

 >24.00

 

* Technique of pitching a lager warm, allowing fermentation to begin, and cooling to the desired fermentation temperature.  

Pitch Rate Calculator :

To achieve appropriate pitch rates run your brewing numbers through Wyeast's Pitch Rate Calculator.  This will not only tell you how many packages of yeast  are needed, but allow you to tailor a propagation scheme to match your beer style.

How Does Pitch Rate Affect My Beer?

Pitch rates make a dramatic difference in the final flavor and aroma profile of any beer.  Ester production is directly related to yeast growth as are most other flavor and aroma compounds.

A low pitch rate can lead to:

  • Excess levels of diacetyl
  • Increase in higher/fusel alcohol formation
  • Increase in ester formation
  • Increase in volatile sulfur compounds
  • High terminal gravities
  • Stuck fermentations
  • Increased risk of infection

High pitch rates can lead to:

  • Very low ester production
  • Very fast fermentations
  • Thin or lacking body/mouthfeel
  • Autolysis (Yeasty flavors due to lysing of cells)

Can I re-use my yeast?

Yeast can be re-used by home brewers but caution must be exercised.  Good sanitation and brewing techniques are vital precursors to re-using yeast.  Small levels of contamination can become very large problems with subsequent pitching. The following are guidelines that should be followed when re-using yeast:

  • Never re-use yeast from a high gravity fermentation (greater than 1.065 original gravity).
  • Never re-use yeast from an irregular fermentation (long lag-time, long fermentation, poor clearing, high terminal gravity, etc.)
  • Never re-use yeast from a fermentation with off flavors and aromas (excess diacetyl, phenols, sulfur compounds, etc.)
  • Never re-use yeast if you are not confident in your sanitation and brewing practices.
  • Do not store yeast for long periods before re-use (longer than 2 weeks typically).

 How much harvested yeast do I re-pitch?

Accurately re-pitching yeast is a difficult task for a home-brewer.  Due to stresses from fermentation conditions, harvested slurry is typically in a less healthy condition than laboratory grade culture  Pitch rates when using harvested slurry should be 1.5-2 times the rate of laboratory grade culture (see Standard Pitching Rates Chart above ).

The following is a guideline for determining concentration (cell density) of harvested yeast:

 

Test tubes showing yeasat sedimentation

 

Harvested slurry is typically in the 40% to 60% solids range.  A home brewer can make a rough estimation based on this information and combined with consideration for all other factors involved (trub content, age of yeast, strain, original gravity, etc.).



Wyeast Laboratories, Inc. © 2014 All rights reserved.
PO Box 146, Odell, OR 97044, USA

Site by Locus Interactive