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Post by itsallaroundyou on Mar 23, 2010 12:10:30 GMT -5
ok, found a bit more in Beckett's Science of Chocolate, 2nd Ed., section 3.2
"The cotyledons (nibs) must be roasted before they can be made into chocolate....In addition, the high temperature, coupled with the remaining moisture in the beans, will kill any microbiological contaminants, such as salmonellae, which may be present on the beans from when they were dried on the open ground...As the beans are purchased from bulk suppliers and may be contaminated with harmful bacteria etc., it is necessary to treat all the beans as if they were a potential hazard until the risk has been removed. The roasting procedure will do this, so once this has been carried out the cocoa is absolutely safe. Analysis of the beans at this stage, known as a critical control point, will confirm this. The main risk is then that the contamination from the untreated beans will be transferred to the rest of the factory. For this reason, the pre-roasting procedures, such as cleaning, are normally carried out in a separate building. The operators are also obliged to change their clothing before entering the rest of the factory."
Looks like the big risk according to Beckett is re-contamination. This is likely very easy to do in a small facility lacking discreet processing rooms. This excerpt also supports John's observations of near 100% kill rates during roasting.
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Post by doclogic77 on Mar 23, 2010 13:25:57 GMT -5
Very interesting. I wonder...would the FDA require me to have seperate rooms to process these. I also wonder if we kept all untreated beans at home and only transported the beans meant for the oven that day if that would suffice.
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Post by doclogic77 on Mar 23, 2010 13:30:11 GMT -5
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Post by doclogic77 on Mar 23, 2010 17:05:33 GMT -5
Most people do not understand the scope of the microbiological dangers of working with chocolate, and underestimate or discount them. Most people do not understand how microbiologically dirty raw beans are, or how difficult it can be to kill salmonella. It's a huge concern to the industry, for it's not a question of if a small scale manufacturer gives salmonella to someone, it's when. Even large companies struggle with this issue, and their microbiological controls are far more advanced than yours (see Hershey, Cadbury for recent examples). Each time this happens, it has a halo effect on chocolate consumers (how many of you were hesitant to buy something with peanuts in it last year when PCA tainted the pnut supply chain? They only touched 1% of the supply chain, but everyone who had pnut products saw huge declines in their sales as a result). The NCA will be hosting a 3 days session on microbiological controls for the small confectioner, geared very much toward chocolate manufacturer in the near future (it may even be posted on their web site now, i've not checked). I'd highly recommend you consider it if you're doing this commercially. Don't get me wrong, i'm not a gloom and doom kind of guy, and i want you all to succeed. Understanding this aspect of your production is CRITICAL, and often overlooked because it's difficult to solve for. Thanks for this! My wife and I are planning on signing up for this. And for anyone who can't make the actual web lecture they will make the audio available to anyone who signs up. You can listen on your own time.
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Post by Sebastian on Mar 23, 2010 19:21:41 GMT -5
I can absolutely guarantee that a non-pressurized roaster, even an industrial one where temperatures are fairly high in comparison to what many here are using and the roast times are longer, and often involve injecting live steam into the roaster, does not always kill salmonella. while cross contamination is indeed important to watch, it's by no means the only vector to viable salmonella in finished product. A very important thing to also consider is that if you manage to get salmonella in your liquor, and you're processing in something like a santha, getting it out so that it doesn't re-contaminate future batches is going to be challenging. Salmonella is a very hardy creature, and i've literally seen pet food plants shut down because no matter how much cleaning they did, they were never able to remove it (the same serotype continually showed up in future testing).
I do see many small bean to bar folks who are doing things like storing their beans in the same area they're roasting them in, which scares the daylights out of me.
I also would not want to set up a home pathogen testing lab where you are essentially encouraging salmonella to grow.
Best advice i can give is to due your due diligence in testing (via a certified food micro lab) a number of batches of beans after you've roasted them at a given roast time/temp to see your micro kill. You're going to want at least a 5 log reduction in TPC. I'd also encourage participating in the NCA webinar, as good info will be available there as well. It needs to be considered as the cost of doing business. Larger scale people who do this for a business salmonella test each lot produced, and they're using equipment designed to mitigate the risk. There's a reason each lot is tested.
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Post by itsallaroundyou on Mar 23, 2010 22:56:24 GMT -5
According to the FDA, you can achieve a 4.9 log reduction in salmonella/g (for peanuts) by dry roasting for 15 minutes at 295F. www.gapeanuts.com/consumer/PBPlantMicroorganisms.pdf claims that roasting peanuts for 30 mins at 270F kills all of the salmonella present (this is unreferenced) (Peanuts are similar to cacao in fat content, but i'm not sure how applicable these numbers are to cacao.) As Sebastian points out, its important to realize that raw cacao isn't the only source of salmonella in the chocolate making process. So, while roasting might kill enough Salmonella to be acceptable, you can still reinfect your chocolate with other ingredients (milk, nuts, flours, coconut, etc..) as well as just in water used in equipment (temperers, etc) and the water used to clean up. How does a raw chocolate producer deal with salmonella? Everything I've read indicates that roasting is the critical step to get rid of it. mike
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Post by Sebastian on Mar 24, 2010 21:09:04 GMT -5
I've done a fair bit of micro and analytical testing on purported 'raw' nibs. I'd stake my pension that, of those i've tested, they're not raw. The micro load was nil (lower than fresh out of most industrial roasters i've seen), and the chemical composition was clearly indicating a heat treatment. What's that old addage? Believe half of what you see and none of what you hear?
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Post by Brad on Mar 25, 2010 1:39:23 GMT -5
Coming from you Meeester Sebastian, I think I'll believe all of it if you don't mind.
Great advice, and thank you for your contribution! I know it helps me!
Cheers. Brad.
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Post by itsallaroundyou on Mar 25, 2010 9:45:33 GMT -5
well, yeah, no offense to the raw chocolate foodies, but just fermenting the beans breaks their "raw" food temp rules, so i don't buy/believe much of what i see on their packages.
mike
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Post by cocoa on Apr 28, 2010 3:14:49 GMT -5
Really?Now I know and thanks for your post. I've learn a lot.
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ktmo
Neophyte
Posts: 1
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Post by ktmo on Aug 23, 2011 4:13:38 GMT -5
We are currently working with a university on a solution to 100% kill without using high temperatures, to ensure the safety of raw chocolate. Will post as soon as we are a bit further down the road.
Am interested though, have there been many cases of contaminated finished chocolate product? The only cases I can find seem to be down to poor cleaning or contamination through leaky water pipes in the plant.
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Post by shrey on Jun 14, 2013 6:14:14 GMT -5
Hi,
Chocolate comes from the seeds of the cacao or chocolate tree. Cacao seeds must be fermented, dried, and roasted to produce the chocolate flavor. Fermentation and drying are done at the farm that grows the chocolate trees. After harvesting, pods are split with a hammer or machete to reveal the seeds covered with pulp. Split seeds are piled in a heap covered with banana leaves or placed in a covered box. While in this heap, the sticky pulp becomes a turbid broth and the cacao seeds absorb flavors from the surrounding broth. The chemical composition of the pulp (below) changes after being kept in this heap for five to seven days.
These changes are the result of microbial growth. So, I think Pathogen is better then Microbial Growth.
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Post by Brad on Jun 14, 2013 15:29:01 GMT -5
Shrey;
I think you'd better look up the definition of "Pathogen". As far as I can tell, (and I'm no biochemist) all pathogens are microbes, but not all microbes are pathogens.
Brad
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Post by littleblue on Jul 1, 2013 9:35:25 GMT -5
A couple of things I do that *may* or may not help the situation. I buy my beans after they have been washed in an organically compatible agent - this effectively sterilises the beans. However, I still do not assume that everything on there is dead - I'm far too paranoid from working in labs and on food for that one. When I get liquor, I get out my crock pot/slow cooker. I put my liquor and my butter into this now and heat them up to just under scorch point and hold it there for 20-30 minutes, depending how much is in the pot. More in the pot, more time at that heat. I use a probe, I stir the chocolate frequently, and I check my temperatures at various places top, middle, bottom, side, centre, etc. I keep all chocolate before the process in one fridge, and I keep all chocolate that has been through it, in fresh containers, in a 2nd fridge. Both fridges are on low temperatures, but not cold enough for dairy, so there's a 3rd fridge for that one! All the cream we use (not milk, we didn't get very good results with milk, so we use fresh, pasturised double cream). goes in before the heating process, so that, too, gets heated up well, even though it's pasturised. In the UK we can get sticks to take samples from our local HSE office and they will also process them for you - fee depends on where you are in the UK, I get mine done for free as a business requirement. When moving things from fridge a to fridge b gloves are changed, containers are chainged, implements are changed - that's something from Italy, never using a container that holds un-heated chocolate to hold heated and vice versa. Colour code if you have to, but keep those things separate and don't make the mistake of taking off a pair of gloves and using your hands at any point, or using the same gloves that you used to handle the first lot to then handle the second lot. Nor scraping your spatula from the first lot on the bowl for the second lot. It sounds finicky, but so far I am coming up with zero ratings, which is more than Hersheys or Cadburys have managed, so I'm pretty happy with it all.
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Post by littleblue on Jul 1, 2013 9:37:57 GMT -5
Oh - one other thing I'm considering is a high rate UV lamp - think sunbed but a lot stronger. They use them on ponds and such to kill bacteria and to keep things like algae down. Excellent for keeping your Koi healthy, and I've considered using one on my beans before they even go into my house from the box.
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