1. After melting the chocolate compound, I am pouring chocolate in the molds.
  2. After pouring the chocolate, I am tapping and vibrating the molds manually. This is getting rid of most of the small air bubbles. So far, so good.
  3. Now comes the main issue. The issue is that air gaps (from what it looks like) are being introduced in the molds, even after tapping and vibrating the molds manually. This is creating white patches on the de-molded chocolate, in the shape of the air bubble.

Here are some pics that showcase the air gaps issue:

Air Gap in Mold 1 Air Gap in Mold 2


Patch 1 Patch 2 Patch 3


Mold used for chocolate in Patch 1


Mold used for chocolate in Patch 2 & 3

From what it looks like, I am assuming that the air gaps are really air gaps and nothing else. Please correct me if I am wrong.

How to get rid of these air gaps so that the de-molded chocolate pieces are simple plain chocolate pieces without any patches on them?


The Air gaps shown in the images do behave like an air bubble. When I manually press on the exact position where I see the air gap, and I keep doing it for few times (4-10) and apply varying pressure, I am able to get the air released from the mold, but that leaves a patch on the actual chocolate, as can be seen in 2nd Patch image.


Adding one more image of the patch to illustrate the issue.

White Patch in the middle of chocolate

Please look at the following image:

enter image description here

From the above image, it looks like the white oval patch in the middle of the chocolate resembles the white mist on the rearview mirror of a car. Not only that, but it also behaves the same, in the sense that I can see the mist in the mold cavity. If I wipe the mist (I think that is what this issue is) in the cavity with a cloth, it just disappears, similar to what would happen if you wipe the mist off of a mirror.

If my analysis is right and if the white patch is indeed the result of the formation of mist in the mold cavity, how can it be prevented to ensure clean chocolate pops out when de-molded?

  • Can you add an image with the chocolates outside the mold? Currently the objects you show look like what happens when you get a thin film of water or oil trapped between two surfaces.
    – bob1
    Jan 22, 2019 at 17:38
  • @bob1 Done. Thank you for your suggestion. I added the images in the Description. Yes, it does behave like an air bubble. When I manually press on the exact position where I see the air gap, and I keep doing it for few times (4-10) and apply varying pressure, I am able to get release the air, but that leaves a patch on the actual chocolate, as can be seen in 2nd Patch image. Hope this makes sense.
    – Devner
    Jan 22, 2019 at 19:13
  • How did you treat the molds beforehand? There are many opinions on this, and few facts. One school claims that one should rub the molds with cocoa butter. This is supposed to improve the shine, but also helps the chocolate to fill in smaller nooks and crannies. What is the chocolate? Is it maybe too viscous? (I often add a couple of percent cocoa butter to the chocolate to improve fluidity.)
    – Popup
    Jan 23, 2019 at 12:48
  • @Popup Tried adding the cocoa butter, yet the result is same. The patches appear as indicated in the photos & the chocolate melts fast. Before pouring the chocolate in the mold, I made sure that the mold is clean. Any dirt is already wiped out with a new soft cloth. There is no residue of water. Just before pouring the chocolate in the mold, I use a hair dryer to blow some hot air on the molds so that the molds turn a bit warm and ready to accept the warm chocolate. Please note that I have tried this by using the hair-dryer and even without it. Both of these methods do not solve the issue.
    – Devner
    Jan 23, 2019 at 14:13
  • @Popup The chocolate is a regular compound slab. The surprising part is that the chocolate is ready in a couple of hours but the air bubble part is killing us.
    – Devner
    Jan 23, 2019 at 14:36

1 Answer 1


These are not air gaps. When chocolate sets, it will shrink a little bit and bend the mold, thus creating these gaps as it sets (they are effectively vacuum gaps). This can be avoided by using a more rigid mold, that wouldn’t bend as it sets.

  • Thank you for your response. The molds are already prepared and delivered to us, so its a bit tough to imagine we can get it changed at this point in time. And of course, even if we do talk to the manufacturer about this, I am imagining they would deny any problem with the mold as accepting it would mean they need to redo the complete set of molds at their expense. So how can we effectively approach them saying that there is an issue with the molds? Can we take any proof of the claim we make? Meanwhile, an alternate solution would be immensely helpful & appreciated.
    – Devner
    Jan 28, 2019 at 23:11
  • Also, the manufacturer used food grade (at least he claimed so) to make the molds. So if I ask him for a new type of material which does not bend, I have a strong feeling that he is going to claim that there is no such material or they simply don't deal with anything else other than the food grade material that they supplied. So it becomes even tougher to convnice him about the issue and get him to agree with it. Do you have any suggestions on this?
    – Devner
    Jan 28, 2019 at 23:19
  • If it helps you, the manufacturer said the mold is made of food-grade Poly Carbonite (PC) material. Does that make any difference?
    – Devner
    Jan 29, 2019 at 9:33
  • @Devner PC is the right material for any sort of molds. However the thickness is the main issue. What are the thickness of the molds?
    – zetaprime
    Jan 29, 2019 at 13:23
  • 2
    I wonder if you could fill the back of the mold with a resin/epoxy substance to strengthen the mold as a whole. The back of the mold doesn't need to be food safe I believe. Jan 29, 2019 at 19:27

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