My mother is confounded by whipping-cream. Some 20 years ago she started making cream-puffs which quickly became her pastry calling card. They always came out great and were always a hit. Some 15 years later, she cannot seem to make whipped-cream anymore.  She still uses the same bowl, same mixer, same whipping-cream (Nutriwhip whipping-cream) and does everything the same way as she used to, but no matter what, the cream stays soft and will not stiffen or form peaks. (The kitchen is not too hot.)  Some explanations that we have considered include:   Changes to the quality/ingredients of the cream (despite the box being the same) Adding powdered sugar to the liquid cream before whipping (like she always used to do) Refrigerator not cold enough (but then, freezer not cold enough either?) Whipping for too long causes heat build-up due to friction, which melts it (doesn’t excessive beating turn it into butter?)   She tried using different bowl, a chilled bowl, a different mixer, (even made me try by hand once!) She has tried a different brands of cream (35% Beatrice and Lactancia whipping-creams), but gets the same results. One time, I tried adding the powdered sugar after whipping the cream, and it was much better than what she normally gets now, but still not as stiff as compared to the past. Using a whisk on the mixer in place of the normal beaters (which was what she always used before, as my and my sister’s tongues can attest to), seems to help, but even that is only temporary.  She has even tried putting the whipped cream in the freezer, and while it does harden, once it has thawed enough to pipe, it gets runny very quickly (in the past, she would be able to pipe the cream onto baked goods, leave them in the fridge for a day, then drive them to somewhere else without the cream’s edges softening).  She is baffled because she had made whipped-cream for various baked-goods countless times, but until a few years ago, she never had any problems, then suddenly, it never works anymore. I found a few related questions here, but they don’t quite apply (they talk about different bowls, different temperatures, etc., but like I said, it used to work).  What could be the problem? How can she get whipped-cream to stay hard like it used to?   Exact brands and variations used:      
Tests  She has tried the frozen-bowl trick (which she never used to have to do), but the cream only stays whipped and forms peaks for a while, then starts to melt (far too) quickly.  Theory  One theory she had was that she was whipping it for too long, which caused heat build up due to friction which in turn melted the cream. This seems to be borne out by the fact that using a wire-whip tends to give desired results more often than using flat-beaters.  Facts  Of course this isn’t a 100% answer or solution because:   She used to use flat-beaters exclusively in the past without issue Even when using a whisk to whip it, it can still melt and fall flat quickly sometimes   Supplemental  In addition, I noticed that she seems to be putting more icing sugar in her whipped-cream than in the past. This likely changes, and specifically lowers, the melting point of the cream just like adding salt to water. We have not done extensive, conclusive testing, but a couple times when she remembered to put in less sugar, it did seem to whip better. This may or may not have been due to the lower sugar content, but it certainly is worth trying if you are having trouble whipping cream.  Conclusion  These observations and tests seem to indicate that the material contents of the cream have changed since the past, and even today, can vary from box to box.  Either way, a wire whisk and chilled bowl as well as reducing sugar (and possibly dyes, and other additives) are the best shot at getting cream to whip. 