Kia ora Koutou!
We have a small business in Aoteaora (NZ) hand making raw chocolate. I would like to buy a stone grinder so I can start to work with the beans and also make a range of nut butters. Can anyone give us some advice on which machine would be best, as I read that the Spectra 40 was not good for raw chocolate due to the temp it goes to as the conch time is longer for raw......Can anyone shed some light our way, Mauri Ora!
Why 40C? Virtually everyone I know in the raw chocolate business works at 47C (~118F).
I can confirm that the CocoaTown will easily pass 40C as Cheebs says - I have measured it. The overal "continuous" temperature in the small (5L) machines hovers between 45-49C based on measuring over a number of hours; the larger machines generate more heat but I've never measured it. With a frequency controller on the motor you can slow the rotational speed down some to keep the temp under 47C, but if you tried to slow it down to keep it under 40C the processing times might become so long that any aromatics would volatilize out.
One thing no one has done (and, frankly, I don't know exactly how you'd do this) is to measure the "instantaneous" shear temperature immediately between the grinder wheels and the base. I am fairly confident that this is at least a couple of degrees higher than whatever the "continuous" temperature might be.
The FACT is that there is no proof that the Howell's enzyme theory of nutrition has any legitimate basis.
The fact that there is no firm consensus as to what defines what is, and what is not, raw.
What we DO know is that different foods have different sensitivities. Lettuces are a lot more delicate than nuts, for example. To hold them to the same temperature standard makes no sense. Another issue that raw foodists don't talk about is time/temp. If I expose a cocoa bean to a temp of 120F for 1/100 of a second does that denature all the enzymes in the bean? Of course not. In fact (and this is a test I've done personally), you can subject an intact cocoa bean to a temperature in excess of 300F for a considerable time (minutes) and not raise the surface temperature of the bean inside the shell above 110F. One reason is evaporative cooling. Think about the volume of a bean if 0.5% of the mass of the bean hits 118.01F and stays there for 10 minutes but 99.5% of the bean stays below 118.0F I think it's silly to say that all the enzymes in the bean are dead.
There's also contact time. There is research that shows that many enzymes survive in aqueous environments above 150F for extended periods of time - hours even.
I have been studying this subject for years and not one raw foodist (in the chocolate world or not) has ever been able to show me one credible scientific study (and no, Gabriel Cousens is not credible) that supports the enzyme theory of nutrition and any scientific basis for picking one temperature over another as the maximum.
THAT SAID, the idea that minimally-processed food is better for you is something I buy into, but it has to be done on a food by food basis - not at an arbitrary cut off that is the same for all foods. There is evidence that broccoli is better for you if it's lightly steamed - better in the sense that more nutrients are more bioavailable.
There is also scientific proof that cooking can create beneficial compounds not found in the raw food. A good example is the antioxidant levels of roasted coffee are far higher than green coffee.
One day, I wish the "raw chocolate" segment of the market would fund a study that proves their claims. Not one company has done the analysis. Having made the claim, the burden is on them to prove their claims - the usual response is, "Prove us wrong." That's not the way it's done.
great write Clay and I am very much with you here.
clay you mentioned 47C above as a generally accepted temp for cacao / choc in the raw choc world. is that for chocolate making only or also the post-harvest processing?
If a raw bean buyer want the beans to be fermented at below 47 i could do it i think although my beans typically ferment higher than that for extended periods of time. but what do they do about the drying beds? anyone who's on a concrete bed is up over 50C at the cement level in the tropical sun for sure, probably more like 55-60C on a hot day. i dry off the ground on elevated beds using mesh, which is cooler than on the concrete but still gets over 50C at times, which i should say I want as i am not selling into raw markets.
just curious about the raw stuff. is any of it really great tasting chocolate in your opinion clay? If you recommend any I'll try and find some when i'm in the US in september
47C (~118F) is the most common max temp I have heard for raw anything.
It's possible to fully ferment below 118F, though pile temps "naturally" want to tend to peak around 122-125F.
While raw chocolate people talk about ferment and roast temps, they almost never consider the temp beans are exposed to during sun drying. As you point out, they can easily reach 140-150F on a drying pad in direct sun. Actually, anything above 140F is counterproductive as the shell tends to crust over at that temp, slowing evaporation of both water and acetic acid. The technique they use in Chuao, though labor intensive, may actually be more efficient from a drying perspective because peristaltic pressure builds up that "pumps" water from the interior of the bean during the mid-day rest.
I know that at least one company is using a large dehydrator system to dry their beans "low and slow."
Is there any great tasting raw chocolate? When you consider the raw chocolate world in and of itself there are some that are much better than others. If you start comparing them with conventional chocolate then raw chocolates still fall short and are generally recognizable. That may change as people start working from the moment of harvesting to optimize techniques to deliver interesting flavors in raw chocolate. I was at a tasting last week hosted by Maricel Presilla featuring Santiago Perralta of Pacari and I have to say that I was very surprised at what they have been able to achieve in this regard. I know that Vanessa Barg of Gnosis just got back from Grenada and that's such a good starting flavor it will be interesting to taste what she's been able to achieve working with Mott Green of Grenada Chocolate Co.
Don't forget the sheering forces in the grinder will destroy the enzymes anyway, no matter what temperature it hits. I posted a link to an article in one thread a long time ago about protein breakdown under sheering forces. I am with you Clay on the minimally processed but I am firmly of the opinion that chocolate must be fermented and roasted, it makes me feel good and that is good for your health too. Don't forget the placebo effect.
Just had a look for that post but it is gone, it was a thread Sam started and it vanished when she left. I think the search I did was along the lines of 'enzyme activity and sheering forces'. Haven't time to look for it now but Clay you might have the thread archived somewhere to extract the info?
I just happened to watch a video about a stone grinder for nut butters and the guy said they also use it for chocolate. Here is the link:
Yvonne, Matt Monarch is a very interesting character. The machine he is hyping is a Santha (Spectra) stone grinder from India. These have been used in the US (and around the world) as grinder/refiner/conches for years. I personally have been using them to make nut butters for years, and I know many others who've been using them this way, too.
I notice the machines were added to the catalog May 21, 2011 - and Matt is hyping them up something fierce. Might news in rural Ecuador where he is, but not in the chocolate world.
That said, my personal experience with these machines is that the basic running temp is around 115F as measured by a laser thermometer pointed right at the point the grinding wheels contacts the stone bottom of the grinder. If you read closely, Matt suggests pointing a fan into the machine to move the heat out more quickly. Not a bad idea, overall. However, no one I know of has actually done any testing to figure out what the instantaneous temperature generated by the sheer action of the wheels on the base is. It might be much higher than the average/spot temp that can be measured by an infrared thermometer.
Our customers are using the ECGC-65-A Grindeurs and Deluxe melangers for nut butters and are happy with the results. ECGC -65-A Grindeurs are easier to use and clean. They also have built in systems to prevent the motor from overheating. There is no need for external fan.