thanks for having a site like this. it is really interesting and helps a lot.
i am not sure if the topic i want to start is already discussed somewhere here, if yes please send me the link and if not i would be thankful for any advise.
i am planing to start a bean to bar small craft, and i am doing at the moment a buisiness plan as well as in parallel i am learning and educating myself about the processes from bean to bar.
one topic where i am not sure how it works is how to inactivate Bacteria in the beans. this is a important topic when it come to the health of the customers.
from one side in the bean to bar world it is said that roasting of the beans at certain temperature kills the bacteria and salmonellas. from the other side some articles online indicates that this roasting process is a primary methode and the temperature used may not be enough to kill the bacteria in the cacao beans.
so what do you think are the main drivers? how do you kill bacteria ? if roasting, what temperature and time you use? sterilisation machines is not an option for a small craft.
is fermenation, sun drying and roasting are enough to eliminates bacteria?
is there any online studies, articles, reports on this topic?
i am thanksfull for any advise or answer.
Thanks for your answer, i apperciate it and it helps a lot.
i would also like to know if there is anything else as the Certificate of analysis i can request from the supplier in order to secure that the purchased beans are OK? like percentage of Humidity, mould, bad fermented, pulp, crashed, insects etc….
could you also advise me which mandatory informations should be included in a contract with beans suppliers?
how can i add humidity to a normal houshold oven?
thanks in advance for any advise.
Welcome to TheChocolateLife and thanks for the kind words.I wish you all success on your chocolate-making journey.
The main microbial contaminants you need to worry about are salmonella and e coli. Depending on where you are you may also need to worry about ochratoxins and aflatoxin. There’s nothing much you can do about the latter two – ask for a certificate of analysis from your bean supplier and also test in a local lab (trust but verify). If you are in the EU you will also need to test for heavy metals – especially cadmium.
The pH of pulp is very low so you don’t have to worry about salmonella and e coli contamination during fermentation. If beans are over-ferment they may end up moldy or mildewed, but they should never be shipped to you. If you can, write up your purchase contracts so you can reject beans without paying for them that get moldy or mildewed during shipping.
The main source of bacterial contamination on the farm happens when beans are being dried. Birds flying over or animals running across the drying pad can defecate and contaminate the beans. If care is taken during drying this should not be an issue (but test anyway to be certain).
Any microbial contamination on the outside of shells can be reduced by roasting (sanitizing, sometimes called the kill step). The amount of reduction is based on a time and temperature formula. The longer the time and the higher the temperature the better the reduction, often referred to in log terms: five nines is 99.999% reduction, four nines is 99.99% reduction and so on.
You can increase the effectiveness of the roasting step by adding humidity to the roasting process. This will shorten the time and temperature of the roast itself. There are some time/temperature/humidity charts you can consult to help you determine what combination you should shoot for.