Problems with chocolate molds

Hi all,

In years past I have been able to use chocolate molds successfully. This year I am having problems, possibly because I switched tempering methods? (I was tabling the chocolate on a granite slab, now I'm using a tempering machine.) The chocolate does not set up correctly. I have tried it using freshly tempered chocolate, and while the knife-dip test sets correctly, and the chocolates I dipped immediately before AND after casting the molds set up correctly, the mold cavities are full of streaky chocolate that doesn't look tempered at all.

My room temperature is 70F, and the chocolate is at ~89F (as far as I can tell; my thermometer appears to be "off" despite calibration and despite being approved for industry, so I have been using the lip test more than the thermometer to determine tempering). I'm working with Valrhona, a mix of Alpaco and Extra Bitter. And, as I said, dipped chocolates seem to be coming out fine with the same bowl of chocolate, it's only the molds that are going wrong.

Any thoughts on what I could be doing wrong?

Tien

updated by @tien-chiu: 04/19/15 01:10:30AM

Tien, what kind of molds and cooling are you using and what is your humidity? With larger masses of chocolate in molds vs. thin layers in dipped chocolate, large flat areas on the bar can easily have release marks or problems cooling evenly. This post and this post describe release mark problems with some of the thinner, cheaper, or badly made molds. If you're tempering at a time of year where it's more humid, the tempering that worked fine before may become much more sensitive to any minor problems. I can temper fine all winter with no dehumidification or AC, but come summer and higher humidity, everything goes to pot without climate control.

Hi Nat,Thanks for the references! They were really helpful.I'm using Tomric polycarbonate molds (which I gather might be part of my problem) to cast shells for some bonbons. The molds are at room temperature and being cooled at room temperature. (I'm not a professional chocolatier, so I don't have climate control, though I could perhaps try to contrive something with a space heater and fan). What is the optimal temperature for casting bonbon shells?But I think part of the culprit might be the humidity! It is pouring rain outside and is expected to pour all weekend, so we have very high humidity. I will try again later this week when it's a bit sunnier and drier out.Could the humidity be causing my other problem, which is the chocolate thickening too fast? I am tempering by heating the chocolate to 120F or so, then dumping it into the tempering machine, putting tempered chocolate on the other side of the tempering machine, and allowing the machine to cool to the proper temperature. Then I leave the machine on and the bowl rotating while I dip the chocolates.In the past this has worked OK, but this year I'm lucky if I get 20-30 minutes of working time before the stuff thickens and I have to temper again. Any suggestions?

Hi Tien,Yes, raining outside with no AC is definitely a problem with both molding and thickening in the temperer. I'd suggest getting a cheap $20 hygrometer online and don't temper if it's ever above 50% humidity if you don't want to chance it. Where are you?Space heater won't really help, but a dehumidifier or AC set on a higher temp (at which it still dehumidifies) are good for lowering the humidity. A temp of 70-79 is OK, but since most temperers use passive cooling, it goes a little faster if the room temp is closer to 70.

Thanks! I'll look into getting a hygrometer and maybe pick up a cheap dehumidifier today. I make my annual batch of chocolates (about 60 lb) over Thanksgiving weekend, so waiting for a better time doesn't really work for me. I live in the San Francisco area (actually on the SF Peninsula about 40 miles south of SF), so our climate/humidity is pretty dry most of the time - except for a few rainstorms in the winter. This weekend's weather has been most unusual - heavy rain and thunderstorms, which are practically unheard of here - so it sounds like I've just been hit with bad timing!Thanks so much for your help!

You may be getting over-crystallization of the chocolate. After about 10 minutes of you working, raised the temperature on the machine 2 degrees. This will keep the chocolate from thickening too much. Good luck.

Thanks Ruth and Nat! I got the humidity in my working area down to 52% and tried again. Between Ruth's hint to increase the working temperature and Nat's to lower the humidity, the molds came out perfect and the chocolate stayed fluid while dipping.Muchas gracias!!

Tien, you might also want to have a fan blow room temp air across the molds to help them cool off. I have found this to be a great help in getting the molds to set and release properly.