My custom plastic molds arrived couple of days ago, looks nice,
the only problem is that even after two hours all the chocolate seems to be liquid in the middle, circle shape.
I mould again today, also in polycarbonate mould, perfect release, no signs of solidification.
I think that I know what the problem is but don't know what os the source: the chocolate kind of "stick" to spicific places in the mould and hence I have an unperfect surface. The chocolate just seems to stay liquid but it totally solid when I demould it.
Any ideas regarding this wierd issue?
I attached to photos: 1. perfect surface of polycarbonate mould. 2. picture of the "circles" on the surface.
(The white batch undergo the same phenomena it just hard to take photo because it's white)
I've seen similar issues when the ambient temperature is on the high side. The chocolate sets a little slower and does not contract fast enough to release from the mold. I don't typically put my molds in the fridge, but I have recently when the temperature in my kitchen is around 72F and the chocolate will set quicker. This problem is also more evident on large flat surfaces. How do you cool your chocolate molds? I also always use a fan when I don't put the chocolate in the fridge.
The air conditioner is on his lowest temperature, the fan is also operates for better convection of the latent heat.
I attach a picture of aluminium "mould" that I used before the new ones arrived, no problems, and also before that, the problem is only in the new custom mould and in all of them! thus, temperature or tempering issues are unlikely.
For reference, same batch, same chocolate, different moulds one has perfect surface and the others not.
It looks like the chocolate set fairly quickly on the initial pour where the liquid chocolate was deposited (round mark).
Do you warm up your moulds before you add the chocolate?
If your moulds are colder than the tempered chocolate, the chocolate that first hits the surface will set rapidly (possibly with the wrong crystal form), while transferring some heat to the mould. Then the remaining chocolate will flow on top and around it towards the corners/edges of the mould, but will take longer to set. This often creates "halos" on the chocolate.
Try to heat up your moulds to about 25-27 degrees celsius before pouring (with a hairdryer for instance) and see if there's a difference.
Ok, thank's. I work outside of my "cold" room, and the ambient temperature is not less than 27C. I will try to mould also to other plastic moulds of the same brand and see if there is difference, although I'm skeptic...
Or, to shake the mould not when I finish my 25 "cubes" (it takes some time and 2.5 full 150cc syringes) but more frequently, maybe it should help..
LLY, do a search here on the CA forums and on The Chocolate Life for 'mold release marks' for some discussions on these marks. The consensus is that they are generally related to molds having a little flex to them. The vacuum-formed Tomric molds that I use have this issue. As the bars cool and contract, the molds flex a tiny bit so they don't release cleanly. The suggestions from Thomas and dublinguy (adequate cooling and pre-warming molds) can help to reduce these marks. I do both, but have only rarely managed to produce a bar with no marks at all.
Bummer. Can you tell us what technique you use to fill the cavities:
- Do you use a spoon - Do you use a pastry funnel - Do you use an automatic depositor - Do you pour a lot of chocolate over the mould to make it overflow (with a ladle for instance) and use a scraper to remove the excess?
I wasn't referring to cavities in your chocolate (I can see from the photo that there are none), but to cavities in your moulds - what tools/utensils do you use to pour the chocolate into your moulds (see list above)?
Has anyone had luck with DIY vacuum formed molds? ..and with respect to release marks, if flex in the mold is the culprit here, would it be possible to beef up a cheaper mold and make it more rigid by backing it with epoxy?