Benefits of Liquid and Dry Yeast
A Comparison of Dry and Liquid: What makes them the same or different?
Many people ask, “Are dry yeast and liquid yeast the same”? While the yeast strains can certainly be genetically identical, the process by which this yeast is grown, stored, and used can be completely different.
We have outlined the major differences between the two culture types, helping you make the decision on which one is right for you.
|Selection||Not all strains can be dried effectively due to the large scale and process of drying, so the selection is limited||Production of liquid yeast is generally smaller scale, flexible, and can be optimized to provide a much greater selection of strains|
|Flavor||Generally more neutral in flavor and aroma. The drying process contributes some stress on yeast, so flavor production in fermentation is muted||Liquid counterparts will have more distinct aromas and complex flavors due to the health and viability|
|Ease of Use||Open package and sprinkle on top of wort (no rehydration required)||Twist open cap and add to wort or pump inline with our FlexPump (Aseptic Transfer System).|
|Flocculation||Due to the drying process, cell membranes can often be deficient in membrane proteins responsible for flocculation. This can lead to less effective flocculation capabilities.||Strain-dependent, but consistent flocculation properties by strain. This is a result of robust cell membranes with intact flocculation proteins, leading to efficient flocculation.|
|Nutrient Requirements||Some nutrient availability in the form of non-viable yeast, adding sterols, nitrogen, and other micro-nutrients||Wort oxygenation is critical, as is adequate FAN and other micro-nutrients|
|Pitch Rate||50-100g/hL, somewhat dependent on actual viable yeasts in the package||Precise cell counts, allowing accurate custom calculations for pitch rate|
|Fermentation Speed||Dependent on pitch rate||Dependent on pitch rate|
|Shelf Life||Long shelf life (12-24 months from production date). Can be stored at ambient temperature, although it is recommended to store it under refrigeration to maximize the shelf life.||Shorter shelf life than dry, but grown fresh with high viability percentage. Should always be stored under refrigeration.|
|Quality Control||Follows strict specification standards for bacterial and wild yeast contaminants per 1 million yeast cells||
The propagation process results in higher purity cultures, enabling the detection of wild yeast & aerobic bacteria contaminants per 40 million yeast cells and anaerobic bacteria contaminants per 140 million yeast cells. This typically allows liquid yeast to be repitched for more generations
|Repitching||Can be repitched, but typically has a potentially higher microbial load (see Quality Control above), which can grow over generations, resulting in contamination of harvested yeast quickly||More sensitive QC specifications allow liquid yeast to be repitched for more generations without the risk of increased microbial population|
|Shipping||Can be shipped in less temperature-regulated environments, resulting in less packaging (insulation and ice) and less expensive shipping methods. Due to its dry form, it is typically easier to import/export in global markets.||Requires cold shipping to maintain viability, which requires insulated shippers with ice and fast shipping methods. Can be challenging to import/export in some countries due to strict regulations for live cultures|
|Cost/Value||Typically lower priced than the equivalent volume of liquid yeast||Higher priced than dry yeast, but better value when repitched as a result of the number of generations that can be gained from liquid yeast|
By carrying out small batch propagations, we can produce a greater variety of strains every week. This means a lot of fresh yeast clearing the QC process regularly, for a wide range of beer (and non-beer) styles.
The small-scale, 21-day process for propagations grown with FAN-rich malted barley results in big, plump yeast cells. These cells have exceptionally healthy cell membrane functions, contributing to the production of significant levels of flavor and aroma compounds.
Grown to a higher level of purity, liquid yeast follows specification standards for bacterial and wild yeast contaminants at < 1 per 300 million(106) yeast cells through qPCR and microbiological plating. While dry yeast has specification standards for bacterial and wild yeast contaminants at < 1 per 1 million(106) yeast cells.
This purity allows liquid yeast to be pitched for more generations without the risk of the increased microbial population from normal brewery handling, leading to increased savings for you!
As an example one ale strain can be pitched 8-10 generations with proper handling:
Dry yeast has a long shelf life ranging from 12-24 months from the production date. This gives brewers the flexibility of having yeast on hand anytime.
- Dry yeast can be stored at room temperature. However, storing it under refrigeration is recommended to maximize its shelf life.
- Dry yeast is more economical for shipping as it can be shipped in less temperature-regulated environments with less packaging of insulation and ice adding to the shipping cost.
- Dry yeast can be shipped anywhere in the world with the headache of customs headaches in some countries, where import regulations for live cultures can be very strict.
FREQUENTLY ASKED QUESTIONS - WLP001 Dry California Ale Yeast
How does White Labs WLP001 Dry California Ale Yeast compare to other similar strains?
Most dry yeasts are produced in a conventional process with propagation, drying and quality control, including WLP001 California Ale Yeast and you will get the same quality, viability and performance you would expect from an active dry yeast.
WLP001 California Ale Yeast is genetically distinct from other strains of similar origin, making this the only California Ale Yeast out there. Our dry yeast is also tested using proprietary qPCR methods, allowing for higher sensitivity for potential wild yeast contaminants. Using WLP001 Dry California Ale Yeast, you will get the craft industry’s most popular strain, known for its clean and robust fermentations, along with the confidence of the uncompromising White Labs quality control standards.
What is the cell count?
The viable cell count is generally 5-10 x 109 cells per gram and a minimum of 5 x 109 cells per gram.
What is the viability?
Dry yeast viability is generally expressed in the number of viable cells per gram rather than as a percentage, like liquid yeast. White Labs Dry Yeast typically contains 60-80% viable yeast with a minimum of 5 x 109 viable cells per gram. The remaining dead yeast provides nutritional value in fermentation, including sterols, nitrogen, and vitamins.
What are the sizes you offer in dry?
White Labs Dry Yeast are available in Professional (500g) and Homebrew (11g) sizes.
How much yeast do I need?
We recommend 0.5-1g of dry yeast per Liter of wort up to 18° Plato.
500g → 5-10hL
11g → 20L/5 gallons
To get specific pitch rate recommendations, see our yeastman.com pitching rate calculator and select Dry Yeast.
How should I store it?
While dry yeast can be stored at room temperature for short periods of time, we recommend storing all dry yeast refrigerated (36º-40ºF/2º-4ºC) to maintain the appropriate shelf life.
Is it gluten-free?
Yes, the yeast is grown on molasses, so it is gluten-free.
Is it organic?
No, it is not.
Why is the color different from lot to lot?
There are color variations, but they have no impact on the yeast's performance or the beer's flavor. These variances are mainly caused by variations of raw materials (molasses) and, to a lesser extent, pH towards the end of propagation.
- March 1, 2023