Brewers dry yeast typically carries over 93% dry matter. The most meticulous conditions are applied during manufacture to avoid microbial contamination, resulting in less than 1 bacterium or wild yeast detected per million yeast cells. The content of 1g of dry yeast corresponds to a minimum of 5 billion live cells but the number will slightly vary from batch to batch.
Dry yeast is packaged in 500g or 11g sachets and must be stored dry, below 10˚C (50˚F). For a few of our yeasts storage under 4˚C (39˚F) is recommended, this will be indicated on packaging and also in the Technical Data Sheets. The dry yeast is packaged under vacuum. Do not use a pack of yeast that appears to have lost its vacuum, resulting in a package that is soft and easily crushed. Both humidity and oxygen will impact on the quality of the yeast and once a pack or sachet is open the yeast will deteriorate quickly. If kept sealed and stored under appropriate conditions, dry yeast can be used up to the expiration date mentioned on the package. Once a pack is open it is recommended to use the yeast as quickly as possible.
Rehydration is a crucial step to ensure rapid and complete fermentation. There are important rules to follow to slowly transition the cells back to a liquid phase. Careful precautions were taken when drying the yeast and the brewer has the opportunity to revert the process to obtain a highly viable and vital liquid slurry.
The following effects have been observed with non-rehydrated yeast under specific brewing conditions:
- Longer diacetyl stand
- Longer fermentation time
- Longer lag phase
- Stuck fermentation
- Poor utilization of maltotriose
There are 3 important criteria to ensure a successful rehydration:
1. TEMPERATURE OF REHYDRATING MEDIA
The ideal temperature for the dry yeast membranes to transition from a gel (dry) to a liquid phase is strain dependent and should be respected in order to maintain membrane integrity during the rehydration process. This temperature varies between ale and lager yeasts. Please follow specific instructions below.
2 . TYPE OF REHYDRATING MEDIA
The media used is crucial to a successful rehydration. Undiluted wort causes osmotic pressure to the yeast and compromises its health. Most yeast strains can be rehydrated in water but lager yeasts benefit from rehydration with a small concentration of sugar, so diluted wort (3° Plato) is preferred.
3 . LENGTH OF REHYDRATION
The rehydration period should not take more than 1 hour and the yeast should be pitched immediately to ensure vigorous fermentation. It is not recommended to store rehydrated dry yeast or a decrease in cell activity will be observed. Once rehydrated, the yeast can be pitched into wort. To avoid shocking the yeast and creating cellular damage, attemperation of the yeast should be conducted to reach the temperature of the wort or at least within 10°C or 18°F. Incremental additions of wort can be added to the rehydrated yeast slurry to bring down the temperature. Rehydration can be conducted in a sanitized vessel. The rehydration media should be sterilized and cooled down to the appropriate temperature.
Please see below for individual recommendations for each Lallemand Brewing premium yeast strain.
Abbaye is an ale yeast of Belgian origin selected for its ability to produce Belgian style beers including high gravity beers such as Dubbel, Trippel and Quads.
Belle Saison is an ale yeast of Belgian origin selected for its ability to produce great Saison-style beers.
BRY-97 is an American West Coast-style ale yeast that was selected from the Siebel Institute Culture Collection for its ability to deliver high quality ales.
CBC-1 has been specifically selected from the Lallemand Yeast Collection for its refermentation properties and is recommended for Cask and Bottle Conditioning.
Diamond Lager yeast is a true lager strain originating in Germany.
London ESB is a true English ale strain, presenting reliable fermentation performance and moderate ester production.
Munich Wheat Beer yeast originated in Bavaria, Germany. It is a neutral strain which can be used to produce a wide variety of wheat-based beer styles.
Munich Classic is a Bavarian wheat beer strain that can express marked spicy and estery aromas, typical to German wheat beer styles.
Nottingham is an English style ale yeast selected for its high performance ability and versatility.
Windsor ale yeast is a true English strain that produces a beer which is estery to both palate and nose with a slight fresh yeasty flavor.