The Pure Probiotic Initiative:
Probiotic Manufacturing: Temperature Control

By Kelly C. Heim, Ph.D.

As living organisms, probiotics require nutrients and water to survive. However, during their residency in a capsule and bottle, these needs must go unrequited until the time they are consumed. To remain viable, the metabolic needs of probiotics must be negligible. Fortunately, this metabolic dormancy is easily achieved by reducing temperature. Accordingly, manufacturing probiotics in a cool environment is required to ensure their stability and potency.

Basic climate control, however, comprises only one aspect of temperature regulation. Probiotics are highly sensitive to sudden changes in temperature, such as those associated with freezing and thawing. Therefore, proper temperature control encompasses two requirements: (1) a cool ambient temperature, and (2) minimal temperature fluctuations. At Pure Encapsulations, both necessities are strategically accommodated throughout all stages, from sourcing to shipping, to ensure full label claim potency of every product that reaches your door.

Sourcing and formulation

Pure Encapsulations’ commitment to delivering stable, clinically reliable probiotics begins in the earliest stages of product development. Since the thermal hardiness of probiotics varies across species and strains, strain-specific stability data is analyzed to determine whether the strain will remain stable through its shelf life, and whether the finished product will require refrigeration. Anticipation of occasional lapses in proper storage on the part of the consumer are taken into consideration at this stage, and the amount of live cells per capsule may be increased slightly to ensure that labeled potency is maintained.

Receipt of raw ingredients

Raw material is received in refrigerated packaging or in unheated trucks during the cold months. Quality inspectors have less than 20 minutes to enter the stock into the system, and material is kept on ice as samples are collected for independent potency and purity testing. As specified by a standard operating procedure, the material must be transferred to a walk-in cooler within 90 minutes of arrival.


Rapid transfer of frozen material to ambient manufacturing conditions causes condensation, resulting in the formation of ice crystals on bacterial cell membranes. To protect the cells from these lethal events, Pure Encapsulations gradually adjusts the material from the storage climate to the manufacturing temperature. This strategic adjustment, known as tempering, has been proven to minimize potency losses associated with condensation. In addition, pre-tempered probiotics are maintained at 4°C, instead of freezing temperatures (~-20° C). This allows for a milder shift in temperature, further protecting the cells from condensation. Tempering protocols are fine-tuned according to the package weight and the stage of manufacturing.


Probiotics that have been properly tempered are stable during blending and subsequent stages of production. The blending procedure is executed using compressed dry air and maintaining a low dew point, making condensation nearly impossible. Keeping probiotics dry in this manner increases their tolerance to any unfavorable temperature changes. As an additional protective measure, the duration of the blending procedure is limited to 90 minutes.

Encapsulation and bottling

Encapsulation and bottling runs are kept small to minimize any untoward effects of ambient moisture and temperature. The use of low-moisture transfer bottles and dessicants also helps protect probiotics from moisture, a factor that can sensitize them to temperature. Immediately upon completion of bottling, finished products are transferred to a designated walk-in cooler.


The foregoing methods ensure the full potency of each product, and by necessity, shipping methods extend this promise. Our shipping methods include high-performance, 3rd-party tested foam refrigerant bricks, second day delivery, and avoidance of weekend transit. Following shipment to hot climates, independent laboratory potency testing confirms that these practices maintain label claim potency, even if the product arrives warm.

Strategic temperature control, applied throughout every phase of handling and manufacturing, is one of many facets of Pure Encapsulations’ commitment to excellence in probiotic quality assurance. This dedication and promise ensures that practitioners can be confident in the potency and reliability of each probiotic product through the date of expiration.