Spoilage in enzymes and starter cultures cannot be seen: the product looks the same while its activity falls, and the problem surfaces only when the production line fails to get the expected effect. That is why the record of what the shipment went through is delivered together with the goods.
The label sets the target temperature, and storage and shipping temperatures do not have to match. New England Biolabs, for example, stores its enzymes at -20 °C yet reports that shipping them at 4 to 10 °C does not harm activity, that its glycerol buffer freezes on dry ice, and that repeated freeze-thaw cycles may cost activity. The choice between dry ice and eutectic plates therefore follows the product's own regime.
The recorder travels in the same compartment as the goods, waiting times at transfer points are logged, and the receiver reads the record on acceptance; the contract states who reads it and when. If the record is missing or a reading is out of range, the lot is set aside.
