# Why doesn't chocolate ever feel cold?

I noticed that every time I put chocolate in the freezer, then I touch it or eat it, it somehow doesn't feel cold at all.

I figured that it must be that it heats up extraordinarily fast from body heat, because if it had a super high coefficient of heat then it would be just as hard to warm it up as it would appear to get cold.

What property would give chocolate that capacity? I've never seen any other substance be put in a freezer and somehow not feel cold.

• I like to freeze my choc to make it last longer - it certainly does feel colder than if refrigerated & takes much longer to melt (my main reason to freeze it!) – RozzA May 8 '18 at 21:44

One possibility is that chocolate has a lower thermal conductivity than water-based foods, which make up much of the food in our freezers.

If you open your freezer and touch a cardboard food container, then touch a metal ice tray, which one feels colder? They are both the same temperature, but the metal tray feels colder because it conducts heat better than the cardboard box, so the heat gets transferred out of your hand quicker and it feels colder.

Water is a relatively good conductor of heat and is present in large quantities in many foods. Chocolate is largely made up of fatty organics, which do not conduct heat as well. It is thus very possible that chocolate has a lower thermal conductivity than many frozen foods and therefore doesn't feel as cold to the touch in comparison.

• that's what I was thinking...the chocolate does not not feel cold; it does not feel cold enough quick enough. – Eashaan Godbole Jun 24 '17 at 4:44
• So somehow it doesn't conduct heat well, yet it melts exceptionally easily? Those two seem mutually exclusive. – RayOfHope Jun 24 '17 at 6:16
• @RayOfHope With "it melts exceptionally easily" reads like referring to a low (relatively to what?) melting point. Comparing water and copper, for example, with water with the lower melting point ($0$ vs. $\pu{1084 ^\circ{}C}$, but with copper the better heat conductivity ($401$ vs. $\pu{0.591W/(m·K)}$ (source: en.wikipedia.org/wiki/List_of_thermal_conductivities) is not supporting an easy causal relation between the two. Nor that the two mutually exclude their presence, either. – Buttonwood Jun 24 '17 at 8:56
• @RayOfHope , as Buttonwood pointed out, even though it may have a slow transfer of heat, the melting point is low so it doesn't take much heat to get there. Just another way of looking at it. – airhuff Jun 24 '17 at 9:00

I think this is a psychological effect rather than a physical one. Room temperature chocolate is pretty close to its melting point (about 30 $^\circ$C), so it probably noticeably softens pretty quickly when it comes out of the freezer and absorbs your body heat, which may trick your perception into thinking it is actually heating up faster than it really is. In fact, the opposite is true; as a substance melts, even though it absorbs energy, the temperature remains constant. The energy is used to re-arrange the molecules.

Edit: Upon thinking about it a little more, due to chocolate being relatively soft, perhaps when it starts to melt due to your body heat, you "squish" it and allow your body heat to penetrate deeper into the material, thus heating it evenly. Compare with ice which is much harder; your heat doesn't get into the center until the outside is melted.