Conching temperature control in wet grinder

Hi All,

just thought I would share a recent idea I had for conching in my wet grinder. Conching is often done at temperatures higher than that reached by a wet grinder. So I borrowed my father-in-law's sous vide temperature control unit and came up with the setup in this video (I'm sure it could be setup neater, but this was just to see if it worked).
http://www.thechocolatelife.com/video/tempcontrolconch

Basically the sous vide machine measures the chocolate temperature. I enter the temperature I want the chocolate to be at and the machine switches a heat gun (pointed into the grinder bowl) on and off to achieve that temperature.

I refined the nibs for 6 hours, added the sugar and refined for another 9 hours. I then switched on the temperature control unit and "conched" for 15 hours at 60.5C. I added the additional cocoa butter 8 hours into that conching period.

The machine I used was a Sous Vide Magic, but there may be others that do something similar.

The final chocolate seemed to have a better mouthfeel and flavour, so I think it worked as a conch. The next step is to try a longer conching period and maybe increase the temperature (especially for milk chocolate). The only thing I am weary of is I don't know the maximum temperature the expoxies/glues used in the wet grinder can withstand.

Anyway, I've only tried this once for now. Let me know if you have any questions about my setup or any improvements/alternatives I could try.

updated by @gap: 04/12/15 02:03:29AM

Well, two things.1) I've done that and decided not to pursue it years ago. The moving air has a tendency to blow off all the subtle (and not to subtle) aromas and even drive off flavor. Made for me a very bland chocolate.2) The Melangers can generally handle 150 F.Seems like "YMMV" seems to apply.The little Premier unit is great, isn't it.Alchemist

As with any tool, there are times when it's quite appropriate to use, and others when it's not. Since not all beans are created equal - nor are taste palates - removal of certain (off) flavors may be desireable - and it may even allow flavors that are MORE subtle, but being masked, to shine.

Additionally, it can help a great deal with moisture removal - which can help with viscosity control.

Very good points Sabastian.I'll admit mine was full bore air flow.But one other thing I've used for years in a non-controlled manner is a heat gun aimed not at the chocolate but the outside of the bowl.

I've been experimenting more with this recently. It's not something you need to use all the time, but it is a tool that has proved very effective on some beans and chocolates. I tend to have the heat gun on almost minimal power so (1) the airflow is not over the top and (2) the heat gun does not overheat - it is a cheap brand I own . It means it can take an hour to get to the temperature I have set, but over the course of a long conche that is incidental.

And yes, I love my Premier

Hi all,

I have set up and am running with a similar setup to Gap. It seems to be working well.

Does anyone know what temperature the epoxies on the Premier wet grinder will withstand? I am about to start conching and would like to know how high.

Regards,

Tim

Alchemist above indicates 150F which, if my maths is right, is 65C

Hi - the heat gun I use goes well over 120 F (it is a professional paint stripper - although a very cheap one). The sous vide unit switches the heat gun on and off in very short intervals (sometimes only on for a second) to make sure it maintains the correct heat and doesn't over heat.

If you google the Sous Vide Magic unit, you will see some info on how it works. Basically all connected as per the sous vide unit instructions.

thanks

I bought a small Johnson Controls temperature control unit (A419) from a home brewing supplier through Amazon. The unit needed to be switched from "switch off when too cold/on when too warm" to the opposite ("off when too hot, on when too cool"). It was an easy switch to make that the unit's manual described well, although I did need to remove the front cover. Easy enough for anyone who can change a light bulb. ( http://www.amazon.com/gp/product/B00368D6JA/ref=oh_details_o03_s00_i00?ie=UTF8&psc=1 )

The heat gun I used is a HomeRight C800781 Heat Pro Deluxe II t hat has some temperature and speed control. ( http://www.amazon.com/gp/product/B003IHVANI/ref=oh_details_o01_s00_i00?ie=UTF8&psc=1 ).

I attached the heat gun to an artist's easel, as it made positional adjustments very easy.

I hope that helps,

Tim

Hi. I have been able to conch with the Cocoa Town tabletop grinders by adding a plastic washer under the center shaft. I made a washer from polycarbonate and one from Teflon/nylon. I lift the stones after grinding and place the washer over the center spindle. I do not remove any chocolate - I use a disposable glove as I don't want my bare fingers in the chocolate.

The washer is about 0.94" thick. The polycarbonate sheets are available at Lowes/HD. A circle cutter makes a nice 2" dia. circle.

The height of the washer prevents the roller stones from touching the bottom of the bowl. The chocolate continues to move and flow but with no grinding.

I also use a similar sous vide setup but with a hair dryer. I prefer the lower temperatures and the steady cycling. A heat gun puts out a tremendous blast of super hot air. This seems to scorch the chocolate and risks damaging the grinder.

The stainless steel bowl is not much of an insulator. Where I live, we try to think about energy efficiency as electricity costs about 80% more here than in the USA. I am going to try and wrap the bowl with some insulation and try to tape it up so that it does not absorb any chocolate when pouring out. You could then regulate the temperature by adding the cocoa butter earlier, if it gets too warm.