Remember, if you find you have an airflow issue, it's really very easy to add a small cooling fan(s) (similar to what computers use to cool their processes) to existing cooling cabinets.  Might be a more budget friendly option than buying new units.  Good luck!

Thanks for the input folks.

My feeling is, it's the inclusions, we are doing some tests as you suggested.

Fridge - we purchased from Vantage House in the UK, this is a fridge designed for chocolate work. We have been using it for years and still, to this day, have never had a problem with hand ladled bars. The only difference is that instead of mixing through the inclusions and hand ladling, we are dousing straight from the machine and sprinkling the inclusions on the back. That's what makes me think its the inclusions. 

Calum - I am taking a look at the specs on the fridge and it's not clear to me what the capacity of the fans is. Air circulation is an important consideration when cooling molds. I've been a fan if Irinox cabinets for a long time but they are really expensive. A good alternative, I have found, is sold by Angel Refrigeration in the UK (ask for Julie Croker and mention my name) – Everlasting. They make temperature and humidity-controlled cabinets specifically for crystallization and holding chocolate.

It's not enough to get the right temperature, you need airflow and to remove the latent heat of crystallization that the bars give off and the airflow need to be top and bottom - under the molds is just as important as over the top.

One test is to use exactly the same chocolate in two different bars – one with and one without inclusions. You'll see pretty quickly whether or not the inclusions are the problem or contribute to it. This will either eliminate the inclusions as a source of the problem or give you a clue that there is something about the inclusions that you need to look at. Temperature could be a factor. I am not sure you have to get them up to 29 ...

10-12C is a little cold. I would start at 15 and then work down by degrees.

well, not knowing your chocolate recipe and not being able to see exactly what you're doing, or  how you're doing it - makes it difficult to say what you must do.  I would say that adding cold inclusions/toppings certainly would be one of the things that i'd assess, as from here it appears that it certainly could be a factor.  Whether it is or not, or if it's the largest factor, remains to be seen...

Edit - do your bars tend to warp more if they're towards the top, mid, or bottom of that unit?  Or does it not seem to matter?

*heat (not hear)

my thumbs on a small phone!! 

Sorry for all typos above, autocorrect!

We use a manufacturer modified (for chocolate work) Foster fridge:

http://www.foster-fridge.com/foster-ep-1440-g-ecopro-g2-refrigerator-with-glass-doors

we set this at 10-12C

So, are you saying that we would have to hear the inclusions to around 29C? 

If i'm reading that right, your inclusions are colder than your chocolate.  That'll cause localized cooling at a faster rate.  w/o knowing more about your cooling setup, it sounds to me like there's an uneven airflow issue.

Sebastian 

the inclusions will be at room temp 18-22C. The chocolate is at 29C when taken off the machine and inclusions vibrated in. Is that a. Station that would effect the cooling?

its strange as we use the chocolate fridge of about 1000 hand Ladeled bars a bay and they cool without any issues.

A dollar says it's the result of uneven cooling.  Is your topping material about the same temperature as your chocolate?

You may wish to consider leaving your chocolate in the cooling unit longer.  You may also wish to put a fan into your cooling unit to move the air inside it around.

Hi folks,

We have done some tests with just plain milk, all looks fine.

Quick thought, the inclusions we were sprinkling on the back were a mix of hazelnuts and sea salt. Do you think the sea salt was drawing in moisture when left sat on the shelves and that may have caused this?

Thanks!

Will try and cool at room temp.

The temps from manufacturer are:

Melting 48-50C

Cooling 26-27C

Working 28-29C

Calum:

You should not have to wait when topping up the machine if you add chocolate that is melted to about the same temperature as the cooling cycle on your machine. So, if the cooling is set to 31C then add melted chocolate at between 31-35C in this way you won't interrupt the tempering cycle. If you add that amount of solid chocolate you may have to wait given the overall size of the bowl.

Although it might take a lot longer to cool - can you test some bars not in the fridge? Let them cool at room temp just as test? It looks like you have inclusions scattered on the top of the bar, can you try without inclusions?

Also - what are the temps on the bag from Belcolade? 45C is a good choice as a melting temp as a starting point and I recommend starting out with every new chocolate using the same set of temperatures and then work from there as it eliminates having too many variables to troubleshoot at the same time.

I forwarded off a link to this post to Carlo at FBM so I knew about the Compatta. Are you still having the same issue there or did you get that solved.

Better quality photo 

IMG_0694.JPG.jpg  •  66KB

- It's bee going on since we started dosing from the machine, we normally hand ladle from the machine.

- We may not have been waiting 15minuts after temp is reached. We only take about 2 - 3 kg out, before topping up. If we were to wait 15 mins between each topping up wee would only get through 8-12Kg per hour. 

- We are using a plain milk organic couverture from Belcolade

- Milk settings 45/29C

- Fridge Temp 10-12C (20-30 mins)

- Room temp 20-22C

- I don't believe there is anything wroing with that machine, it must be our settings as it also happened on our dark Compatta machine.

- It 7kg Prima

- Out of interest, what do you advise as a good setting on the auger, as we have this setting on our Compatta

- See photo for bending - it happens a 20-48 hours later. 

Thanks all! 

IMG_0694.JPG.jpg  •  26KB

Calum -

How long has this been going on and have you been in touch with FBM yet (and where are you located)? Do you have the FBM Skype account for technical support?

Is this a chocolate you're making or a commercial couverture you're buying?

What are the temps you're using for the chocolate (bowl heater temp and cooling system temp).

How long are you waiting after the machine says it's "ready" before you start depositing? You should not start immediately as it takes some time to circulate all the crystals once the temperatures have equilibrated. I recommend 15 minutes at a minimum.

Basically, if you have the temper dialed in properly then this (the bending) should not occur. So, there's something about the way you are using the machine - or there's an issue with the machine itself - that's causing the issue.

My guess is that you've got a lot of lower-form crystal formation going on. That could be because you're not cooling the chocolate to a low-enough temperature. I need to know more about how you're using the Prima ... you can't use it the same way you use a batch tempering machine.

Is this a 7kg Prima or a newer 10kg Prima? If it's a 10kg machine, do you have a speed controller on the auger (and if do, what speed is it set for)?

Hi Clay,

Its a FBM prima.

when you say it might not be tempered, do you have an idea what might be the issue?

im going to get some photos tomorrow, hopefully.

thanks all.

Calum -

What machine are you using for tempering? If you never had problems hand-ladling then it may be that you think the bars are tempered but they are actually not.

Specific formula please, and photos if you have them?

They are plain milk bars. 

Melting 45c

tempered 30.5

Dosed straight ff the machine.

80g bar 150 x 80 x 9mm

Cooled in fridge at 12C for 30mins

they then appear to be fine and then a couple of days later they bend.

We never have this problem when we hand ladel, I just cant get my head around this.

Any help is, as always, much appreciated.

Can you post your formula, your cooling settings (temperature both in and out of the cooling unit, time spent in both areas, etc), your bar dimensions, if there are any inclusions in it, and how you know you're tempered?

Thanks Brad. I'm pretty sure they are tempered. 

Without knowing what your chocolate recipe is, and assuming that you have enough cocoa butter in your recipe, I would have to say that your chocolate is not tempered properly.  

Hi all,

Looking for some advice.

We are starting to get a fair few of our bars bending when they come out of cooling (our chocolate fridge). I can only assue that they are cooling too fast? 

Any tips most welcome.

Thanks

Calum