Forum Activity for @Clay

Martin - Thanks for sharing!

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.

Mark:

Patience. You need to wait for the chocolate and the miracle of proper and sufficient crystallization. These look to be mold release marks. I would definitely wait before you try to demold and see what happens. Your molds may not be clean enough or they may not be the right temperature when you put the chocolate in them. And ... what's the temperature of the room you're working in the humidity, and the temp and humidity of whatever you're using to cool the chocolate?

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.

In a recent article in Confectionery News , Fairtrade has announced a partnership with Mondelēz that should mean more Fairtrade cocoa will find its way into Cadbury products in the UK & Ireland. This is to be done through expansion of the Cocoa Life program.

However, in a troubling (to me) comment from Barbara Crowther, Director of Policy and Public Affairs at Fairtrade, [the cocoa for Cadbury] "isn't going to be certified either under the Fairtrade mark or through the sourcing program. It's going to be traded through loyalty payments embedded into Cocoa Life itself and we will work to hold that program accountable ."

We should take into account the fact that the International Institute for Sustainable Development, in its most recent report on cocoa, says that less than 40% of the cocoa that is certified is sold as certified. That means that the producers pay for the certification of 100% of what they grow but, on average, receive the premium on only 40% of what they sell that is certified.

This fact is not one that is advertised by Fairtrade, which is hardly surprising, as I think it's part of an overall lack of transparency with respect to how premiums do (or more importantly, do not) always make it to the producer. While there is an inordinate focus on paperwork and documentation up the supply chain, there is no corresponding documentation or commitment down the supply chain.

There are other aspect of Fairtrade's work that also need to be examined, one of the most heinous of which is the concept of mass balance, which guarantees a complete lack of traceability back to the producer in countries where this is practiced.

What immediately occurs to me, when Fairtrade says, "Trust us, we'll work to hold the Cocoa Life program accountable," is that they first must hold themselves accountable for the premiums that are collected and how those premiums are disbursed. My immediate suggestion is a report on the flow of money, down to the producer (co-op) level. If they can come up with total dollar amount for premiums collected globally, they should know the numbers that roll up into that number on a country-by-country basis as well as on a producer-by-producer basis. If they don't ... then their global numbers should probably be considered suspect.

What the industry needs is more transparency, not less transparency. Fairtrade has not earned my trust because they have never fully documented the flow of money back down to the producer. Fairtrade positioning itself as the monitor of Mondelēz's cocoa portfolio for the UK and Ireland is asking way too much and it is naive on our part (consumers' part) to assume that the job will be done properly.

The article talks about Mondelēz's $400 million, 10-year commitment to improving cacao farmers' lives and livelihoods. Last I looked there were something like 15 million people who rely on the income from cocoa in whole or in part. $400 million over 10 years is $40 million/ year, which is less than $3/year per person. And that's assuming that all $400 million actually gets spent in productive ways? How much of that $400 million is caught up in administrative overhead and other expenses?

Maybe this new initiative will produce positive results ... but I one thing I am fairly certain of is that the only news that will be published will be positive and glowing: the system is not designed to report its own shortfalls. We can only wait to see what sort of reports are produced, but I am not sanguine that the effects will be meaningful, especially absent any promotion or connection with Fairtrade. What will be the consumer messaging around this? How are they to know?

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)?

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.

Dan:

Welcome to TheChocolateLife!

Where are you located? Were you at The Chocolate Show in London? I was there.

All machines were sold!

The "market price" for cocoa at the close of trading was under US$2675 according to ICCO . And the trend is downward.

This price represents what a buyer should expect to pay for bulk-quality cocoa from West Africa with no certification premiums, and is either from the port (FOB), or delivered to the customer. The price does not represent what the farmer gets paid.

In Ghana, the price paid to farmers is set by COCOBOD - the Ghana Cocoa Board. This price is at a discount to the market price does not directly track changes in the market price. Instead, it's a price set several times per year, and is something like a 40% discount to the market price. So, if the market price averaged $3000, the farm gate price would be around $1800. Most cocoa gets traded on the public markets at prices that are directly influenced by the market price. Premiums for quality or certification are most often "marked" to the market and expressed in one of the following forms, "market plus ten percent" or "market plus $XXX dollars).

One major concept behind directly trading is that the buyer gets to work directly with the producer and they negotiate a "fair" price. Usually, this price is at a premium to the market price. So - if the money is paid directly to the producer that generally represents a good deal. However, not all companies report the farm gate price they paid. Notoriously, one NYC-based chocolate maker reported that they paid over 4x the market price for a batch of beans. Looking closely, the price also included all of the transportation and brokerage costs as well as extraordinary costs associated with the transaction.

"Fair" prices for certification are set by the certification bodies. Fairtrade has one, organic has one. Right now, FT is $200/MT and I organic is about the same. Because of the way the system is structured, very few producers ever sell all their cocoa for the premium price, so the average premium they receive can be a negative amount ... they end up losing money producing certified cocoa.

What is fair depends on many factors, and while those factors are pretty much the same from origin to origin, the cost of living from origin to origin is different. So what's fair in Bolivia is not fair in Peru is not fair in Mexico, or Hawaii. Unfortunately, schemes where the premium that is paid is the same around the world exert negative pricing pressure.

So - go do your homework at origin. Find out what's actually being paid and understand what the cost of living is, and more importantly, what the incentives to labor in the farm economy are. In Tabasco, Mexico we learned that even the cacao producers' union - which represents over 25 co-ops and more than 10,000 farmers - is selling cacao at a price that is not sustainable to its largest customers.

FBM - NW Chocolate Festival Show Specials

UNICA 40
New for NW Chocolate Festival
New! Larger 40kg working bowl
New! Updated design
Craft Chocolate Upgrade w/ auger speed control
Enrober-ready w/ belt speed control
Pneumatic doser
SINGLE-PHASE 208~240V

KLEEGO 50
A true conche for the small-batch chocolate maker
50kg capacity as a melter
35kg capacity as a conche

RUMBO
60kg melanger/refiner
Real granite grinding stones and base
Direct drive (variable speed and reverse)
Integrated hot-air warming
Self-emptying design (bowl does not tilt or spin - improved operator safety)

QUADRO 10
10kg batch temperer
Compact, energy efficient
No plumbing required

MINI-MONO
Countertop chocolate melter for drizzling on gelato, ice cream, baked goods.

DETAILS
All machines are 208~240V 60Hz, three-phase except where noted.
NW Chocolate Show Special: 20% discount off show machines .
Customer is responsible for removing the machines at the end of the show and shipping from the venue.
Price includes shipping from Italy and customs clearance.
Contact Clay Gordon for details about placing the order.

I have never had any problem contacting Blommer on the phone to purchase product in bulk (1MT of cocoa butter direct) or to find a local dealer in the NYC area (1 bucket of cocoa butter).

The local retailer in Brooklyn is a broadline pastry ingredient supply company.

I would call them, not email them: 1-800-825-8181.

Where are you located?

Wendy - I am sorry there are not. Where are you located? I may be able to do something.

As do the Belgians. The French would use bon bon (good good).

No - in general, raw cocoa materials are not sterilized. People have improved production processes, but subjecting the beans to temperatures above 100C (no matter the duration) is not something most raw companies are prepared to do - and still call the product raw.

One of the challenges with the raw diet is that you don't know if (or how much of) the benefits are coming from eating raw food - or not eating processed food. (I've been researching and covering this topic since some time in 2009.)

Yeah - the main point is "cold processed" but the word raw has a lot of baggage attached to it with respect to specific (but not universally agreed upon) maximum temperatures.

Helion -

Generally raw chocolate makers don't sterilize.

Part of the challenge is that they don't understand the physics of heat transfer - the just focus on a temperature and think it's an absolute limit. Subjecting the outside of a cocoa bean to 100C/100%RH for 1 minute does not cook/kill the bean - but it will do at least a 3-4log kill on salmonella and e-coli. In fact, it's barely enough time for the heat to penetrate the shell, and you do have to consider evaporative cooling. 

I am confident they've never thought about the instantaneous shear temperature under the grinding wheel. If the chocolate, on its own durning refining, warms up to 45C then the shear temperature has to be higher.

The most common sterilization process is high temperature "dry steam." This is often done in a pipe when the beans are being transported from the cleaner/destoner to the roaster.

Another method would be to inject water into the drum of a drum roaster.

When using a convection oven you want one that is plumbed and so you can inject moisture into the cavity of the oven. Some convection ovens are programmable with precise controls over humidity levels (e.g., Unox, Angelo Po) so you can program a specific humidity levels for a specific time during the same point in the roast cycle.

In addition to sterilizing the beans, the humidity will cause the shell to separate slightly from the bean inside, resulting in less cocoa butter transfer in roasting and a bean that is easier to crack and winnow - as long as it is not allowed to cool completely

The bars should be easy to remove from the mold, have no release marks, and have a nice crisp snap.

Hi @melisandegosselin - welcome to TheChocolateLife!

Raana -

This is the company you are thinking of: http://www.chocolateriedeprovence.fr/ ?

Ursula -

I would go to a local used restaurant equipment dealer and look to find a used bread proofing cabinet. You would not hook up the water because you don't need humidity control. New cabinets can cost as little as $1000, so used should be much cheaper.

The temperature control range is right in the middle of what you're looking for.

You can take the chocolate out of the tempering machine and put it into hotel pans that fit the racks in the cabinet.

San:

One of the challenges with "raw" is that there is single, accepted, maximum temperature. Some say 42C (Douglas Adams coincidence?), others say 45C, and the most common one I've heard here in the US is 48.7C (118F).

One of the challenges I have with a single temperature definition is that it assumes that all foods (and all enzymes) react the same way to heat. I know that Excalibur, a dehydrator manufacturer, cites research that says that enzymes are more durable in aqueous environments. They can "survive" for far longer times and far higher temperatures than the ones you cite.

From a process perspective, trying to express butter from liquor at low temperatures is inefficient - time consuming and expensive.

Furthermore, there is no proof that I am aware of that there are living enzymes in dried cocoa beans (drying is a stage missing in your process diagram, and I take issue with the order of other steps). If there are no living enzymes in raw beans then it should not matter what temperature the cocoa butter is processed at. Also, to the best of my knowledge, there has been no peer-reviewed study that tracks changes in nutrient levels from the bean in the pod to a finished bar that conclusively shows any benefits from consuming "raw" chocolate.

So - from my perspective - the distinction is meaningless.

But your customers obviously care.

Trent -

NCW is a commercial company whose business is selling products and services to confectioners and chocolate makers. 

You can promote your business on your profile, but if you want to promote product or services here in the Classifieds - you need to help cover the costs of keeping the servers running and the software up to date.

Please send me a PM or email to discuss.

Thanks,
:: Clay

Sebastian -

The /reddit thread is spectacularly unhelpful in explaining how/why this works.

There is a lot of bandying about the word hydrophobic but the question remains, how are the gold powder particles selectively removed from the (cocoa? coffee?) to stick to the surface of the chocolate?

What's the chemistry of this, do you know?

Ilya -

250kg week is 2500, 100gr bars or about 3500 70gr bars. If your mold has 3 cavities in it and you can process 3 molds per minute thats 3x3x60 or 540 bars/hour. So, molding 250kg would take 5-7 hours per week at those speeds. Tempered chocolate requirement is ~35-50kg/hr.

Cooling time is dependent on several things, with the thickness of the bar a key factor. A 7mm-thick bar is going to take a lot longer than a 3mm-thick bar (the time difference might not be a linear function).

If it takes 15 minutes to cool down a mold (a cooling tunnel will make this much faster, BTW), then you need to have a minimum of 45 molds at 3 molds/minute if everything went perfectly and there were no delays. To be safe you will want twice that number.

Throughput is going to be dependent on getting your molds into the mold loader, de-molding at the other end, and returning the mold to the mold loader.

One of the things people think is that going to a cooling tunnel eliminates labor. That's not strictly the case as you need people to operate the machine. A skilled operator and manual dosing can do a lot more than you think. It's about organizing production to be efficient.

A case in point is to consider that at .5 meters/minute you need at least a 7.5 meter cooling tunnel to keep up. And that's going to mean a lot of walking from one end of the tunnel to the other.

[ That's not the case with the Selmi bar tunnels because there is one fold. They go down to one end then move to another level, and return to the beginning. ]

A specialized crystallization fridge with 20 racks can probably hold 80-90 molds. It might cost you $6-7000 delivered. By the time you put the bottom tray into the fridge the bars on the top rack will be ready to take out. The operator can work at their own pace - it's not dictated by the machine.

When you need to double production, duplicate the line. It will be less expensive and require less space. When your production projections reach into the 1000 bar/hour range and you have to run at that pace for more than 5 hours/day, then go get a tunnel. And then consider a folded (vertical) tunnel not a linear tunnel.

I don't know how adjustable the cracker on the Selmi machine is. 

The machine I am talking about works more like a scraper/peeler. There is a stainless steel plate with holes in it and a paddle-wheel-like device that scrapes the beans against the plate, breaking them. Larger beans and pieces stay in the chamber until the pieces are small enough to fall through the holes into the chamber where forced air separates the shell from the nib.

There are three fractions - and the speed of the cracker wheel and the fan can be adjusted to fine-tune the separation. One fraction is fines and shell, another is usable nib, and the third is a combination of nib and shell. You can wait until you get a lot of this combination fraction (i.e., at the end of the day) and run just this fraction back through the winnower to get as much usable nib as possible. The 100kg/hr figure for the small machine assumes two passes to get below 1.75% maximum shell in nib.

I will get up-to-date pricing over the weekend and get it to you.

Rochelle -

I have seen one. They are beautiful (which is to be expected for Selmi products) but the winnower is expensive for the throughput they offer. If aesthetics are really, really important to you then I don't know that there is a better option in this price range.

If aesthetics are not as important, but throughput and budget are, there is a company in Peru that offers one for about 60% of the cost that delivers about twice the throughput.

Ilya -

You mention small production above - how large?

Because, before we go anywhere talking about any specific machine or approach ... it is very helpful to have an estimate of your bar production needs? Hundreds per hour? Hundreds per day? There is a huge difference in how I would recommend approaching this depending on the production volume you are talking about.

That said, one of the nice things about flood/scrape mold loaders is that you can fill different mold configurations without having to adjust anything in the line (assuming all the molds are the same size). The downside is that the method can be very messy and it does not handle mixed-in inclusions very well.

Pneumatic depositing options fill each mold cavity separately. They are more expensive, but the process is much cleaner. That's an advantage when going directly to a cooling tunnel as excess chocolate on the outside of the molds can get caught up in the drive mechanism.

You can DIY a cooling tunnel using a series of chest freezers bolted together. Remove the door (lid) and build a wooden collar (8-12 inches high) on top of each unit (this is done all the time for jockey boxes for craft beer to hold the taps), then attach the door to the top of the wooden collar.

Create openings in the collar for the conveyer to fit through. Put a PID control unit in each freezer to control the temperature of each unit separately. Put a fan in each unit to move the air around inside (you can build internal baffles to direct/control the airflow). If humidity is a problem, put a dessicant inside each freezer.

3, 7-foot chest freezers give you the base for a ~21-foot tunnel for well under $5000. PID controllers are going to be less than $100 each. I don't have a price for a conveyor unit but you want a surface that will allow air flow underneath the mold and you want the speed to be adjustable. You want the conveyor to be at least 18" longer on each end (3 feet overall).

21 feet is approximately 7 meters. If the belt speed is .5 meters/minute then a mold will spend about 14 minutes in the tunnel. If you are using 275x175 molds then the max throughput is just 3 molds per .5 meter so you're talking about max throughput of less than 3 molds/minute. If you need to work faster you need a longer tunnel.

With separate PID controllers you can set the temperature of each freezer differently. If ambient is 68F you could make the outside units 62F and the center unit 55F (I recommend an odd number of units for this reason). Of course, you can make this any length you need by selecting different freezers - though they should all be the same dimensions for obvious mechanical reasons.

Keep in mind that a cooling tunnel that is designed for enrobed items is not optimal for molds as there is no airflow to the bottom of the mold. So - a purpose-built tunnel for molds is going to be better.

If you are doing batches of 450 bars at a time, the question I have is how many batches per day and week are you doing. If the answer is one then a fridge designed for holding and crystallizing chocolate is going to be a better idea. It will be much smaller and much less expensive.

Noel:

You can't take your experience with the various processes of batch tempering and apply them to continuous tempering.

The chocolate that comes out of the pipe - when it's in cooling mode - is the temperature set in the cooling cycle. 30.5C you say. That drops into a bowl of chocolate that is heated and whose sole purpose is to melt out all the crystals before it exits the drain at the bottom and runs through the tempering pipe.

When the chocolate is melted and before you turn the cooling cycle on, the temperature of the chocolate in the bowl should be fairly even. The longer you let it run, the more even it will be. There is a thermocouple on the outside of the bowl and that's there the temperature is measured.

When you turn the cooling cycle on, the temperature of the chocolate coming through the spout drops. (The thermocouple is right at the top of the tempering pipe.)

Eventually, you start pumping 30.5C chocolate into a bowl of warm chocolate whose max temp is 47C ... and you start mixing them together. If you put a probe thermometer in the bowl you will not get consistent temperature readings. This is to be expected. You don't really care what the temperature is anywhere in the bowl except at the very bottom by the drain. All you care about is what temperature ensures that crystals are melted out before the chocolate re-enters the tempering pipe. If there are still crystals there is the risk of a positive feedback cycle leading to over-crystallization.

From a consistency perspective you want to keep the working bowl at least two-thirds full while working. Don't empty the bowl. The emptier the bowl the harder the heating and cooling systems have to work. You'll quickly get into a rhythm where you fill some molds, then do some other work (moving molds to cooling, de-molding, etc). While you're doing this other work put chocolate into the bowl and allow the tempering cycle to re-establish itself. If you can put melted chocolate into the bowl and the chocolate is about the same temp as the cooling temp then you won't interrupt the tempering cycle and can resume work immediately.

But - the important take-away is that a probe thermometer inserted into the working bowl will not return any useful information. The temperatures will be different throughout the bowl. That's to be expected - it's the way it works. One thing to note about the geometry of the working bowls in FBM machines is that they are narrow and deep. This design reduces wasted heat - wide shallow bowls are less energy efficient. The design also provides more time for the chocolate in the bowl to melt out crystals.

The Selmi line you show is not for molds. That setup requires a TOP with mold loader accessory, Tank400, and cooling tunnel - plus room for the cooling tunnel. Last I checked it was in excess of US$70k.

You can get a new Unica from FBM with your choice of 50/100/200kg tanks, pneumatic depositor with mold loader, and CLIMA 50 folded/vertical cooling tunnel for less than the Selmi equivalent.

If you want to cool in a room or fridge instead of using a cooling tunnel I'd need to know how many molds/bars hour/day you want to produce and to think about the options. You can build a room (I know someone producing >10K bars/day that way) or get specialized humidity-controlled chocolate crystallization fridges.

I also know of a way to DIY a cooling tunnel using chest freezers and PID temperature controllers ... if you have the room.

Is this on the surface or all the way through? What's the texture of the bars that ar affected?

Do you have a recording thermometer/hygrometer? What's the temperature of the room ... and what's the temperature of the fridge?

When you say "This is proving to be unsatisfactory" can you provide some more information about what ways? Throughput? Quality?

AMF = Anhydrous Milk Fat (aka butter oil)

There are no books that cover the topics you ask about.

However, I can answer any questions you have about FBM continuous tempering machines. Do you have a 12kg Compatta or a 15kg Compatta?

About assessing temper. Learn to do it by hand. Even if you have a continuous machine - it will only do what you tell it to do. If you don't know what proper temper is you can't tell the tempering machine what to do.

Sebastian - Thanks for sharing!

Calum -

As a point of comparison:

2xMaestrias (45kg) with pneumatic depositors (maximum size of inclusion of about 3mm) will cost you under €50,000 total. 2x200kg melters cost under €20,000. Mold loaders add another €15,000 all in.

FBM is introducing a new one-shot in the Fall but I don't have pricing on it (won't until after they return from holidays) and I don't know what the max inclusion size is on the one-shot but I will ask.

A 50 mold vertical cooling tunnel is under €30k and the 100 mold tunnel is under €40k.

If you wanted to buy all this equipment, I quoted catalog list prices above - I am confident FBM could take care of you.

The customer doing so many bars a day has some products where the inclusions are mixed in (such as flaked coconut) and others where the inclusions are vibrated in.

Calum -

When you say that the Pomati line you link to in the PDF is extremely expensive - what do you mean? And, when are are adding nut inclusions, what is the maximum size of the inclusion that the Pomati line can handle?

Personally, I would not invest everything in a single line. Single point of failure and the overhead involved in changeover is going to be significant. By having parallel lines - two or more - you reduce these risks and costs. If you are producing different kinds of work I would look to create solutions tailored to the work being done rather than one line that needs to be reconfigured for each different type of product.

I have one customer here in the US who is doing 10,000 bars per day each using FBM Maestrias, each backed by a 200kg melter. They build a custom cooling solution (room). All of the bars have some sort of addition (powders, inclusions) in them. 

Assuming 200 working days/year, 400,000 bars is about 2,000 bars per day. At five molds/minute and three cavities/mold, that's 900 bars/hour. If each bar is 50gr you need 45kg/hr of tempered chocolate. The T20 which is quoted in the line has a max throughput of 24kg/hr so right away I see a problem - you need a larger tempering machine.

The current Maestria has a 45kg working bowl and can temper up to 135kg/hr. FBM is introducing a new Maestria in the Fall with a 60kg working bowl and three-zone tempering. The Unica will be upgraded to a larger working bowl as well, at least 35kg if not 40kg, giving it a throughput of 70-80kg/hr. FBM offers a pneumatic depositing option for the Maestria and the Unica (and both offer three-zone tempering) or consider a one-shot machine that they plan to introduce in the Fall as well.

Of the companies in Italy offering this type of equipment, Pomati is the youngest. I can't speak to the large machines because I have not opened the backs and looked inside, but the smaller machines tend to have underpowered motors which can affect longevity when they're put into high-duty-cycle operation.

:: Clay

There is no simple answer because I don't know what kind of molds you are using (thermoform has different heat transfer characteristics than polycarbonate), the dimensions of the mold cavity (the thicker the bar the longer it takes), the temperature of the chocolate (it will take longer if the temper point is 32C compared with 30C), and the amount of airflow in the cabinet (how efficiently are you removing the latent heat of crystallization - which can be affected by what the molds are resting on). 

I don't know about the temperature the bar has to reach (outside? how do you measure the internal temperature?) but there are some important clues: what does the surface look like and what is the snap? A soft snap is an important clue that the bar is not yet fully crystallized.

All that said, in a 55F cabinet with chocolate at a 30-32C temper point (86-90F) in a polycarbonate mold with good airflow top and bottom - you are looking at 12-15 minutes minimum.

I personally don't know anyone who's selling used equipment for this scale of production.

You may find someone selling used in the UK here in the classifieds on TheChocolateLife. CocoaTowns and their ilk are likely, I have no idea if there is any used Kudvic machinery, but they are comparatively expensive, per kilo of batch capacity, new. You could contact CPS to see if they know of any used equipment.

Malcolm at Vantage House may also know of used items.

Do you know Vantage House ? They handle pretty much everything you need if you are interested in smaller-scale production. How much chocolate do you want to make in a given day/week/month?