Uneven tops on chocolates cast in magnetic molds??

[pastryani]

Hi Choco experts - a couple of questions for you tonight:

 

I tried 2 new molds today - 1 magnetic the other a regular polycarbonate mold.  When I unmolded the magnetic hearts, the top surface looked 'off' somehow (left pic), I couldn't figure it out.  The tops of the chocolates from the non-magnetic mold looked fine (right pic):

(Btw - I'm not talking about the swirling, which is another issue that I can't figure out, but one thing at a time. )

 

I figured out that the surface of the left pic was ever-so-slightly uneven and tested this by rubbing the chocolate against a flat surface:

You can see that the flat/level areas of this mold are the outer edges and the center, but the areas in between those are slightly lower.  Has anyone experienced this?  I know it's a small detail and not as evident when using a transfer sheet but it *really* hits the OCD part of me (and I wouldn't expect that from such a pricey mold).  Why isn't it level?!!  (The magnetic plate seems level btw).

 

Now onto the swirling... 

It's most pronounced in the magnetic heart but is also visible in the other heart.  I cast these molds twice to see if I'd get the same results, checked the temper twice, and each time and it looked good. But the results were the same. So what gives?!!

 

[Lisa Shock]

Did you paint the molds with a light coat of chocolate before pouring?

Did you refrigerate before unmolding?

How did you handle the molds, were your hands or fingertips touching the bottom of the mold as you filled it or moved it?

 

The chocolate as it sets up generates a bit of heat on its own from the motion of the crystals, so, sometimes chocolate that is in temper goes out of temper when molded. You usually see this with larger molds.

 

I have also seen chocolates go out of temper because a mold got warm from the chef's fingers and went out of temper in fingerprint-like ovals where they held the mold. I have hot hands, and fill molds while they sit on a chilled quarter sheet pan.

Hope this helps!

[pastryani]

Hi Lisa - thanks for your reply.

No, I didn't paint the molds, I just poured chocolate into them.  Would painting result in a more even surface, or are you talking about the swirling issue?

 

My hands may have been in contact with the bottom of the mold, but only very briefly.  I should note that the first time I used the mold at room temp (65F), and the second time (thinking it may have been too cold) I warmed up the metallic bottom until it was about 75F - same results for both (uneven top and swirls).

 

Yes I put them in the fridge for 5-10 minutes after casting.  

 

Wondering what else to do here - The unevenness is driving me nuts!! 

[Lisa Shock]

Painting might help both issues. I'd also try pouring at a slightly lower temperature, even a degree or two may make a big difference. The unevenness may be due to uneven contraction during cooling. I'll defer to other members with more experience, though.

[pastryani]

Hmm okay I'll give both ideas a try and see what happens. Thanks for the suggestions!!

[Kerry Beal]

Anita - are the backs on your magnetic mold plastic or metal?

 

As Lisa mentioned - I think the swirls are the unmolding marks that you get with large smooth surfaces - and always seem to be worse with magnetic molds because the back/top of the magnetic ones is usually a lighter material than the polycarbonate of a non magnetic mold and as the chocolate crystallizes and contracts the mold material needs to do it's bit in the reaction. Same thing happens when you mold on acetate - you tend to get more significant unmolding marks because the acetate doesn't contract in a complimentary fashion to the chocolates contraction.

 

That being said - as Lisa has said painting the molds first may go a long way to correcting these issues - but large flat surfaces are always troublesome. 

[pastryani]

Hi Kerry - the backs are metal.  Its so interesting, I thought the metal might've been the problem, but I wouldn't have even thought of the acetate being an issue.

 

I'll definitely try the painting the molds and let you know how it works.  Thanks Kerry & Lisa!  

[Kerry Beal]

Another thought - is it a name brand mold or a knock off?

[pastryani]

Hmm I'm not sure... It's unmarked which leads me to believe knockoff, but it wasn't cheap.  I have paisley molds by the same company and they worked fine.  Are you thinking knockoff = poor quality = bad results? 

[Kerry Beal]

 Possibly if magnets aren't very strong and the back gets some warping when it is in place

[pastryani]

The plate seems to be level and quickly snaps in place, but I don't have anything else to compare to. . Ahh well, will try the painting today and let you know!  Thx!

[pastryani]

Update: I recast the molds in the usual way (with white chocolate), and overall the surfaces looked more even in the white choc than in dark (strange huh?).  However, the swirling was definitely still there.

 

Then I tried casting again, this time by painting the insides (with dark chocolate), and then casting in the usual way.  There's a little bit less swirling, and they're a little more level, but not perfectly level.

 

So at this point, I'm thinking it's just me who's noticing this and I need to get over it!!  Thanks both for the ideas - they helped!

 

[Lisa Shock]

One more tip, this may or may not work so well, so maybe run a test: try not refrigerating so quickly after filling. If it's due to uneve contraction of the mold itself, and your room is already fairly cold, maybe you don't really need much of a refrigeration step, maybe none at all. Hope this helps!