Hi there, I am quite new to bean to bar and was wondering if anybody can help with advice. After refining my nibs for about 24 hours in FBM rumba kid, I put natural cane sugar slowly and all thr problems start here. Firstly, it immediately becomes very very thick, secondly it takes about 4 days till all the sugar refines more or less properly, otherwise it feels like eating fine sand, and the chocolate is quite gritty. I tried increasing the pressure of the wheels, but the machine started to vibrate and shake a lot... I do not think I need to adjust the pressure every time. It refines the nibs absolutely fine, but not the sugar.. Anybody has an idea why is that happening? Is it sugar or the machine issue? Thanks in advance!
Dear LND777, very often happens that someone new to BEAN TO BAR World has difficults with Rumbo Kid, and this is only a matter of practice of how to add ingredients. Contact us as soon as you can. You can do it by e-mail, by Skype call, by Whats App…. how you prefer! Both our technicians and our commercial departement are here available to assist and help you for everything you need. We wait for your news ! Have a good Day!
There are a lot of different things going on here, so let's try breaking them down one by one. I don't think it's the Rumbo itself but something about the specific way you're using it.
First - have you communicated with FBM directly about your experience? firstname.lastname@example.org is the email address. When it comes to changing the pressure on the wheels did you tighten at the driveshaft or at the wheels? It is possible to apply too much pressure, in which case the wheels might no longer sit flat to the grinding stones. (This is more likely to happen in other melangeurs where both wheels are on the same axle, but it can happen on the Rumbo, too.)
Second - There is no need to refine the nibs for 24 hours before adding the sugar. In the Rumbo I recommend adding the nibs in the recipe in three equal amounts with about 30 minutes between the additions. Beginning 30 minutes to an hour after adding the last batch of bibs you can start adding the sugar, again in thirds, 30 minutes apart. You also need to consider the moisture content of the sugar. An unrefined cane sugar may have a higher moisture content so you'd want to get the temperature in the Rumbo higher while adding the sugar to remove the moisture.
Third - Do you know the fat content of your beans? If the fat content is very low then I can see that adding sugar will make the mixture very thick and reduce the efficiency of mixing. If the product does not mix well then there will be problems refining all the sugar.
Four - At what speed are you setting the rollers? In a big Rumbo, I refine at a speed between 3 and 4 on the dial. When you go faster than 5 all you're really doing is pushing most of the mixture in front of the wheels and it never ends up being refined. This is a case where the faster the wheels go the slower the process goes.
We've been having good results in a Rumbo with refining times of between 24 and 36 hours depending on the kind of sugar and the amount of sugar in the recipe. Refining nibs into a very smooth liquor only takes a few hours ... less than four, even with a full load.