Polishing Panned Products

Here in Australia we are having really strange weather. Bushfires and record temperatures a couple of weeks back and then very heavy rainfall. It's all adding up to high humidity which is proving "interesting" for chocolate - especially polishing in a pan.

At the moment I can't get below about 60% RH although I have had my dehumidifier on for days with the room closed.

I have a home based business working out of a converted "spare room". I know that I need to work more on sealing it better. But there is more to the problem than that. When the temperature reduces the RH increases. Sadly the dehumidifer also stops working or it goes into a "de-ice cycle" and then the RH soars and if I am polishing I have MAJOR problems.

While there is seemingly nothing I can about it (the manufacturer tells me) I HAVE to fix the problem.

One thought is a dehumidifier that also heats the air to drive up the "dew point". More "non-chocolate" technology to get my head around and pay for too. I think costly.

Another is to use a dessicant dehumidifier. In essence, the raw, moist air is blown into a silica gel wheel where the water is removed. The wheel then goes through a heater where the water is driven off and exhausted to the outside air and then the cycle is repeated.

SOUNDS like a neat solution and seemingly not too costly (about $5,000).

But I don't know anyone that has done this.

Does anyone have any comments please? I need to fix the problem!

Thanks!

Colin

Colin -

Try using quantities of bamboo bio-char. I ran across this company a couple of years ago and have used this product in a number of installations where the problem was not quite as severe as the one you're describing. This is a US company but I know they source their bamboo bio-char in SE Asia.

They are quite cheap (the large bags retail for US$23 each) and are good for about 50 cubic meters. You might need four or five or more to address the problem - but they are still really cheap and they require no energy. You could get many more than you need and instead of cycling them monthly, cycle them weekly.

BTW - these bags are also good in refrigerated display cases where there is no humidity control as well as for any application where refrigeration is required and humidity is a problem.

That is seriously interesting Clay! I do wonder how it would go in a commercial sense though. A possible application is to pop one of the bags in the pan overnight and seal it when I've done a batch and then the load should be be ready to polish in the morning!

The room sizes they speak of are tiny - for muppets I think! Very interesting concept though!

I WAS wondering about using a system to take my RH to 30% but have had feedback that this would dry the job out too much and make it chalky.

Colin

30% is way too low for chocolate. 50-55% is about right.

I suspect a combination of approaches will work. I would hate to invest $5k in a big dehumidifier and find out it doesn't work.

When working with the Moso bags (you might be able to find a local supplier for something similar in bulk and you could use another wood - bamboo is used because it's so fast growing) I always make sure to increase air circulation if I can and make sure the bag is in the airstream. They are small, but I used one for a self-made walk-in cooler of about 80 cu meters and had no problem, in part because there was very little air transfer. They are surprisingly effective. And cheap. Hanging one in the bowl and covering it up would remove excess moisture from the air in the bowl for sure.

Thanks Clay. My big problem is in the polishing stages. I use Capol 5021A (Gum Arabic) for the polish and Capol 425M for the seal.

The instructions for dark chocolate for Capol 5021A is that the temperature is to be 16-18C (12-14C for milk and white) and the RH 40-50%. Same with the seal (Capol ). Also, once done, the product must go onto trays for at least two hours before packing. In practise I usually leave it overnight and then either pack or put into bins for later packing (so I can select the pack sizes that I may need as I sell product).

The dehumidifier I use is a refrigerant type which means that it freezes water out of the atmosphere. There are two drawbacks. One is that it suddenly goes into a "de-ice" mode where the humidty soars - suddenly it's up to say, 65% from 48% which of course renders shock to the job I am working on making it sticky and then the seal layer of one piece fuses with the seal layer of another piece and then they tear and the job is bad. Secondly as the temperature reduces I can hit the dew point and then my dehumidifier fights with my air conditioner and the humidity goes up beyond acceptable levels.

Much of this is a problem of being very small. There are dehumidifers that dry the air then heat it to avoid the dew point problem. I have not really examined this in detail as I know that it's outside of my budget. I would also need to install bigger air conditioning - also costly.

Part is also that I work from home and the sealing on the room I use is sub-optimal.

So I wondered at installing a dessicant dehumidifer and was not sure if going ever lower for the RH% would be an advantage.

You say "no" and I have now had advice from Capol that it would be a bad idea too. So I won't do that.

So I am still seeking a way to get the RH dwon and keep it constant. Temperature is not so hard - although anoything below 18C gets challenging - especially here in Sydney in summer time (now) where it has been up to 42C in the past month.

Thanks for your thoughts - I'm going to try to find some of that bio-char here!

Colin