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Post by threechocolatiers on Nov 18, 2010 16:00:42 GMT -5
We tried our first roast today - unfortunately we burned our beans. We were confused on how to end the roasting process in the Behmor 1600 once the beans started to crack. Do you set to the cool cycle and allow the beans to continue through the cool down or is there so another procedure we should be doing to end the roast?
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Post by jtoddm on Nov 18, 2010 17:55:14 GMT -5
On the Behmor you can simply press the cool button and the cool down cycle will start immediately. If you are finding your beans are still over roasted you can look at how long you were roasting for and shorten the time. You have to be careful though, on some roast profiles (i.e. anything not P1) taking a few minutes off after you start the roast is different than shortening it before you start the roast.
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Post by vxaktor on Nov 18, 2010 18:05:13 GMT -5
We have used the Behmor 1600 on 4 roast so far. This is what we have done and as of yet the beans have not burned.
Load a 2.5 to 3 lbs of beans push the "1" pound button, "P1" and start; this automatically gives you 18 min.
If more time is needed towards the end of the roast (say with 20 secs. to go) push the "+" button this will add on 15 sec.
At the end of the roast the machine automatically begins the "cool down" stage. In the above scenario the "cool down" stage is automatically set for 13 min.
Hope this helps.
Robert
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Post by Brad on Nov 19, 2010 1:43:21 GMT -5
My two bits for what it's worth:
I don't believe for one minute that cocoa beans can be optimally roasted in 18 minutes, or even 30 minutes for that matter.
All of the roasts in our factory are between 45 minutes and an hour and 20 minutes, and ALL at low temperatures of around 300 degrees F.
For the past month I've been researching the appropriate roaster for scaling up my company's production to about 700,000lbs per year, and have spoken at length with some of the most well respected chocolate professionals in the world - including Christopher Taylor who is reputed to have helped Bernard Minifie write what is considered today's chocolate bible "Chocolate Cocoa & Confectionery"
Chris concurs with our roasting times, and agrees that shorter, high temperature roasts do nothing but burn beans, and destroy the delicate notes that good quality beans are revered for.
As I said before, these are just my two bits for what it's worth. Low temp. Longer time = a better, gentler roast.
Cheers. Brad.
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Post by tony on Nov 19, 2010 8:49:10 GMT -5
Hi Brad, My roaster is almost ready to go to work and I read your earlier post. 300F = 148.889C. You say for time (obviously I know it depends on da beans) but what would you consider a "safe" profile.
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Post by Brad on Nov 19, 2010 14:09:25 GMT -5
When I'm testing cocoa beans I go by smell...
The roast starts with a nice toasty "brownie baking" kind of smell. Then it begins to turn acidic. Then it gets quite acidic. In fact if you smell them at this stage the smell should more or less clean out your sinuses! After that, the acid begins to dissipate, and the brownie smell begins to return. Any time after the acid dissipates you can stop the roast. Note however, that roasting will almost never remove all of the acid. It will always be somewhat tangy when you smell it. The longer you roast after this point, the fewer fruity notes will be in the cocoa, and the richer the cocoa will taste when made into chocolate, (up to the point of where you actually burn the beans of course!)
Hope that helps.
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Post by Sebastian on Nov 19, 2010 16:58:22 GMT -5
Here are some dry roasting micro kill profiles. Micro kill rates are impacted by many, many factors - bed depth, air flow, static or drum profile, initiate bean moisture level, whole bean/nib roasting, etc. These profiles are for a static roast with a bed depth of 2", non-agitated, non-pressurized, and extremely good heat distribution (no cold spots in the oven), and no steam pre-treat on the beans to de-bacterialize it. Post roast cooling was done statically in ambient conditions.
265 F for 45 minutes yields 3.8-4.5 log kill 280 F for 25 minutes yields 3.6-4.5 log kill 295 F for 15 minutes yields 4.0-4.6 log kill 310 F for 12 minutes yields 4.2-5.0 log kill
Not sure if this is the best place for it, but Tony's inquiry into safe profiles sparked my memory, and as many of you know, this is an area i've been quite vocal on.
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Post by Brad on Nov 19, 2010 17:06:36 GMT -5
Hey Sebastian;
Can you please elaborate a bit on what the term "4.2-5.0 log kill" means?
Much appreciated
Brad
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Post by Sebastian on Nov 19, 2010 20:27:34 GMT -5
because micro-organisms exist is such large quantities, effective destruction of them is measured on a logarithmic scale. for cocoa beans, i'd suggest you want a 5 log kill - which means that you've reduced your TPC (total plate count) from 10^6 vegetative cells/g to 10 cells/g. It's the measure used to determine how effectively you've addressed microbiological food safety.
For reference, the Schwans ice cream contamination that occurred in the mid 90's that sickened a quarter million people had a salmonella count of 6 cells/gram.
Last year i did a small micro survey of a number of micro-batch chocolate bars (TPC only, I didn't look at pathogens), and some of them were in the 10^9 /g range. For those of you who are microbiologists out there, i apologize for the sudden feeling of cardiac arrest i just gave you, as you understand how bad that is and what it means. I continue to urge all of you to understand this implications of this and what is necessary to control them.
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Post by Brad on Nov 19, 2010 23:39:17 GMT -5
Thank you!
That was VERY informative.
Much appreciated Sebastian.
Brad
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Post by ephramz on Nov 20, 2010 0:38:20 GMT -5
Thank you everyone for the great info on this post. We were just contemplating a Behmor but decided against it due to the small capacity and high power bills for electric roasting vs. gas.
Brad, your roasting profiles sounds much longer than anything we've ever done (10-25 min at 300° F in a convection oven). If we do it any longer the beans really start to taste charred. What are you roasting in, and do you think our oven might have such hot spots that the temp we're reading with a thermocouple is not accurate and it's actually much hotter?
Sebastian, thanks for the plate count info. Do you happen to know of any documented food poisonings from infected chocolate? I know how careful big chocolate manufacturers are about this and it must be for a good reason, but I've never heard of a case of chocolate poisoning. Of course we don't want to have one, which would be a huge blow to the chocolate industry. How do you do your plate counts? In your own lab or do you send them out?
Know when you're coming to Hawaii yet?
-Nat @ Madre Chocolate
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Post by Sebastian on Nov 20, 2010 7:10:17 GMT -5
Here's just a handful, spread out over time to show it's not clustered around certain times, over multiple geographies, and only for salmonella as that's the pathogen of main concern. Company name left off, but since they're all public recalls, if you're so inclined you can easily link it to the date. According to the CDC, only 3% of Salmonella cases are ever reported, than 1.4 million cases/annum exist, and cause approx 600 deaths/year in the US (CDC, 2005, Oct 13).
1970. Sweden. S. durham. 1973. US/Canada. S. eastbourne. 1982-1983. United Kingdom. S. Napoli. 1986. Canada. S. nima 1987. Norway. S. typhimurium Germany, Denmark, etc. S. oranienburg 2006. UK. S. Montevideo. 2006 US. S. enterica, serotype? 2007 Canada S. typhimurium
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Post by oaxacalote on Nov 21, 2010 1:06:36 GMT -5
Point taken. Thanks for the info Seba.
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Post by ephramz on Nov 21, 2010 3:45:03 GMT -5
Thanks for that concise listing, Sebastian. Is that listing compiled anywhere else, or is that put together from your own research on this topic? Just wondering if there's a good clearinghouse for contaminated chocolate cases.
In looking into 3 of these further, the one in Norway in 1987 was possibly caused by outside bird contamination, as a paper on the topic explains: "Although we cannot exclude the possibility that the outbreak was caused by contaminated raw ingredients imported from a foreign country, it is tempting to speculate that the outbreak strain may have been derived from an avian wildlife reservoir in Norway. Although the chocolate factory was relatively modern, the possibility exists that birds may have gained access to the plant and introduced contamination somewhere along the production line. Indeed, birds were observed in the factory before the outbreak, an observation which is not unusual in the food industry. Inspection of the factory revealed several opportunities for contamination from various sources, especially during transport on open conveyor belts."
And the Canada 2007 one was from a broken sewer pipe in the plant. Couldn't find the source of the 2006 US case since it never left the plant and so seems never to have been investigated publicly.
I agree that cacao can usually have high levels of pathogens on it especially since it is often dried at ground level where chickens may have access to it, so we all have to be super careful, but I wonder how many of these cases could've been avoided by proper sanitation at the plants and at the cacao farms (drying in covered, bird-excluding areas).
Craft chocolate makers have a bit of an advantage in having more of a personal relationship with their cacao suppliers and can check on the conditions at farms, but we can't possibly check all shipments at their source or after they're processed into chocolate given the cost ($200-300/batch at food safety labs). We don't want an outbreak, especially in artisanal chocolate to give chocolate a bad name, as has happened with so many other food pathogen outbreaks in the past decade with spinach, beef, peanut butter, etc.
Has anyone come up with any intermediate batch size check for pathogens that is affordable? Can we learn to do this ourselves with agar plates, fume hood, incubator, and microscope?
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Post by Sebastian on Nov 21, 2010 7:14:12 GMT -5
I'm not sure craft chocolate makers have an advantage in regards to incoming bean cleanliness vs anyone else. At the end of the day, you can't be present during most - and for many of you - any - of the post harvest. Bird netting is fine and all, but what about lizards, or bugs? How do you keep the wind from blowing in bacteria? What about rain water running off the roof through the netting? And for those of you who have your cocoa shipped in ocean going vessels - how do you keep the holds free of birds, or birds off of the slings? If you protect your sling, how do you keep the ocean spray from washing some of the next guys over to yours? If it's containerized, how do you ensure your container was sterile, so that if your container is placed at a level in the ship where temp swings are such that it passes the dew point and you get precipitation inside your container? What about a maintainence program to repair / replace torn netting? How about once they're packaged in jute sacks and transported and stored at the port - how do you keep birds off of the rest of your supply chain? By nature of how beans are fermented, dried packaged, moved, and stored - they are raw food items and micro-biologically hot. There's simply no way you can prevent that in origin - no matter how many controls you put in place. And i'll bet you a case of your favorite chocolate bars that should you put in an inspection program where you physically visit your farms and exporters on a given frequency, what you see on the day or two that you're there isn't going to represent how most of them will do things when you're not there If I were you, instead of testing every batch, I'd take the following approach: 1) give a LOT of thought into your mfr design to prevent contamination of clean (Roasted) materials by raw materials. 2) contact the NCA and ask them about information they have on micro food safety for craft manufacturers 3) conduct a micro survey on your finished liquors, using your specific roaster and your specific roast conditions to build confidence that you're getting the micro kills necessary. once you've built that data-set, you can use that as your control points (time and temperature) to guide you. Hit those parameters and you may not need to test every batch. I would not recommend doing the testing yourself - you do not want to intentionally grow salmonella... 4) SHARE your information. as you begin to bulk up your knowledge and confidence in your systems, make that available with others. Since most of you are using similar systems, there's good learnings that may well translate from point to point. Collaborative efforts is synergistic, and should precede competition. Guys - i sort of feel like i'm having to prove my case over and over and argue a point here - at the end of the day, i'm trying to help you. I get that it's uncomfortable, that many of you don't really understand it, and that it's hard. Some of you think that because you've been doing this for a year and no one's complained, you must not need to be concerned about it. At the end of the day, you're going to do what you're going to do - but i've got quite a bit of experience here. When one of you has an event that sickens people - and you will - the FDA will step in to control it. If you don't have something established indicating you've done your due diligence to appropriately control the food safety issue - especially if you were aware of it - you're going to be in a far worse off place than if you've done your homework.
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