It should never be “necessary” to refrigerate brazing pastes prior to their use. The need for any refrigeration of pastes is a carry-over from the "old days" when brazing was being done in hot heat-treat shops where the ambient temperatures were hot enough to cause breakdown of the brazing-paste binders, and the binders could no longer suspend the brazing powder. In such shops the brazing paste was stored in "cool places" such as refrigerators.  

Please understand that there is absolutely nothing inherent in the chemistry of the binders used in making brazing pastes (by any manufacturer) that is enhanced, or made better, by refrigeration. Refrigeration is only needed to prevent the breakdown of binder systems from excessive heat in the brazing shop.  

In most brazing shops that I visit today, the rooms where the brazing filler-metal (BFM) pastes are stored are actually quite comfortable and often air-conditioned. Thus, storing the brazing-paste containers in the cabinets in the room is perfectly satisfactory, and any "refrigeration" warnings can be very safely ignored.  

Having said that, please note that if the brazing paste is stored in very warm room conditions, it is possible that the excessive heat could cause the binder systems in the brazing pastes to lose their suspending capabilities, and the paste will be said to "break down," (i.e. the brazing powder will sink to the bottom of the cartridge or container, and the liquid binder will rise to the top).  

This does not mean that the brazing paste is bad! It merely means that the binder system can no longer suspend the brazing powder. So, stir the brazing paste thoroughly prior to use, and then use it immediately before it begins to settle out once again. Continue this procedure until all the paste is finally consumed.