Some Guidelines for Creating Chocolate Formulas
Posted by Jeff Stern on September 05, 2017
Making chocolate involves more than just roasting and grinding beans down, throwing them in a stone grinder with some sugar, and hoping for the best. To ensure you get a consistent, uniform product every batch, you need to carefully measure and weigh your nibs, sugar, and cocoa butter (if being used), and preciely formulate your chocolate according to certain rules. Ideally, you need to control for moisture content, adjust for viscosity if desired, and calculate your processing times and temperatures. It's important to carefully consider all your variables. In this post, we'll cover some aspects related to the post-winnowing (removing shell process). We'll touch back on winnowing in another post.
Stone grinders allow more leeway in product formulation than does using a roll mill refiner. Stone grinders don't require a certain fat content in the formula, while roll mill refiners will get the best film and most efficiently process when the fat content is at the proper percentage. This is ideally somewhere in the 27% range, give or take 1 or 2% either way. If you have the option of adjusting roller temperatures, fat content may be less of an issue. However, you may cause excessive wear or even damage to the rolls if proper temperature settings and gap sizes are not followed. And having rolls reshaped can be extremely costly.
To create a proper formula, ideally you know the fat content of the beans you are working with. Fat content can vary widely. However, this is not always possible as it requires serious laboratory analysis. So, it's usually necessary to estimate the fat content of the beans when working your formula, which is about 54%, but can range from 48-57% (Beckett, S.T., Industrial Chocolate for Manufacture and Use, p 34). With estimates, you can usually but not always get close enough with your formula to run a roller mill with proper adhesion of the chocolate film.
Many small "craft" chocolate makers avoid adding cocoa butter to their chocolate in order to keep the origin 100% pure. This makes processing on a 3 roll mill difficult, as fat content cannot be adjusted unless you are pressing your own cocoa butter from the same beans you are using for chocolate production, or are willing to use commercially bought cocoa butter. Using a stone grinder avoids this problem, as no additional cocoa butter is needed.
You may also want to adjust fat content after roll refining in the conching process, or during final stone grinding to control viscosity and flavor. You might also want to use lecithin. There are proper percentages of fat that must be used depending on the end use of the chocolate, be it molding bars, confections, enrobing, dipping, or other purposes. We'll discuss these in another post.
Included here are links to production formulas and spreadsheets to help you calculate your chocolate formulas. The first is based on using a Buhler SDWC-600/200 3 roll mill . The second is a general sheet to help you calculate your percent cocoa content. This is useful guidance when trying to make different bar formulations, for example a 50%, 62%, 70% etc.
Many variables can be adjusted for chocolate. Please get in touch with us if you'd like further guidance or advice on formulating your chocolate products.