Professional emulsions area released to market at close to ideal colour balance with the expectation they will be consumed a lot sooner than, for instance, consumer emulsions, which are manufactured with a lot more allowance for shelf-life and are quite good even if they are past their expiry date. These films are often left in cameras for anything from a month to a year, so age slowly.
From early experience, Velvia / Provia that has expired and/or stored improperly will be casted with a noticeable change to anti-halation characteristics and loss of speed. If prompt exposure and processing is the norm, then only normal refrigeration is required. For me, film bought in bulk joins the rest of the film (both exposed and unexposed Velvia, Provia and Delta 100) in the freezer at –20°c. Film stored like this must be allowed to "warm up" prior to use for 6 hours before loading to prevent condensation. When travelling, a small 'esky' (Australian for icebox!) with ice bricks is fine, but this is only necessary in hot environments over extended periods.
