18 year old film - Kodak Royal Gold 25 that's been refrigerated. Shot at box speed, processed normally straight up scan with no color/contrast post work. Perfectly fine.
18 year old Kodak Ektar 125 left out in a hot Atlanta open driveway. Shot at ISO32, processed at box speed, straight up scan with no color or contrast post work. looks normal.
If you only have one roll, you might try overexposing by 2 or 3 stops to compensate for speed change although most color negatives can handle overexposure by much more anyway.
On the whole, I have been surprised by how long outdated film can last and still produce very acceptable results. OTOH, and from experience, I'd be very dubious about spending any money on 15 y.o. 400ASA consumer film.which had never been fridged or frozen. As Chan Tran suggests, new films are not prohibitively expensive, as compared with your time, possible disappointment, and the wasted cost of processing if unsuccessful.
On the whole, I have been surprised by how long outdated film can last and still produce very acceptable results. OTOH, and from experience, I'd be very dubious about spending any money on 15 y.o. 400ASA consumer film.which had never been fridged or frozen. As Chan Tran suggests, new films are not prohibitively expensive, as compared with your time, possible disappointment, and the wasted cost of processing if unsuccessful.
On the whole, I have been surprised by how long outdated film can last and still produce very acceptable results. OTOH, and from experience, I'd be very dubious about spending any money on 15 y.o. 400ASA consumer film.which had never been fridged or frozen. As Chan Tran suggests, new films are not prohibitively expensive, as compared with your time, possible disappointment, and the wasted cost of processing if unsuccessful.
Sorry I just intend to reply railwayman but from tipping you are adressed both - never mind - I find no way to awoid (don't come back with set up

)
Okay railwayman3 - to explain (the most you might know - I be sure)
Professional Films (within the past) were shipped after a period of storage by manufacturers and came to stores in "couled" condition. This was in regard of finest characteristics (I doubt a bit and sugest "further reason" but that should not be the issue here) - and you had to use it imediately or you had to store it "couled" within the expiration guarantee.
No prof had problems to come to expiration because of weekly demand to New Films.
So no prof would had made experience with expiration of professional films.
No prof would had taken such riscs.
Of course professional films will hold characteristics some time after expiration but sure they suffer.
With amatheuric films it is different : In the past they came fresh produced into shipping (remember the billions demand per year in the very old days.)
BTW that practice with fresh films also changed today (I will not commend issues here).
Generaly the task of amatheuric films was (amatheuric workflow) to use a film during holidays.
(hot temperatures) to hold the last years Christmas film over month in the camera till it is finished.
So amatheuric films may be more resistent ? Perhaps - but I doubt a bit (they should have same resistence) but they were shipped the day after production (in the past

)!
And generaly c41 Films can be used outside guarantee for a xx time.
That xx is different from color layers/ couplers / design!
If you have some luck the colors bleach out intensity rate (sorry for that english) is nearly the same from expiration to each single layer. So you lost saturation of your film till the day x were the first color shifts are visable come.Then the sifting is killing the original characteristics of films more and more.
From my point (hope PE will not insist

) that process of "oldering" is different to the process of oldering with developed films in regard of long time storage of finished films.
For sure such processes of damage are simular but not 100% identical.

(hope)!
And some films (simular with bw emulsions) can be used AFTER expiration. From my point one year without problems (without couling) - the process of damage is caused in a form of multiplicating
storage time x log storage temperature.
So you might have no chances in case of high temperatures. Some amatheuric photograpers remember from storage films during holidays in their cars


. Some of them used professionell films for better quality and stored in their cars

But if you have a special emulsion from c41 with less color shifts intensity you'll louse grain characteristics and intensive colors but it may hold for some years (for me the min. sould be after
1 - 1,5 years after expiration of c41 Films - max. time is limited from 4 - 6 years.
But it is relative from the point you realy identify "visable" change. Remember most c41 are from design more saturated.
From my point the duration to a point of unacceptable characteristics may be at 2 years after expiration - 7 years. But that is an individual relative point.
Sure you can forget biggest prints after expiration - but for smal prints or for scanning workflow?
It is highly dependable.

and most different from film to film. And some of our younger fellows
love such characteristics and began to store fresh films on a heater!
A very good method to destroy films - belive me

!
with regards
PS : cheap expired Films are better prepared for heater storage
