Guidelines For Pumping Chocolate, How Sweet It Is!

Chocolate processing has its own unique challenges that call for specialized pump and application knowledge to ensure smooth operations and compliance with industry standards. Viking Pump has decades of experience addressing those challenges and successfully handling chocolate using our internal gear pumps in various chocolate manufacturing processes.

Although the term “chocolate” refers to many different recipes, some chocolate applications are harder to handle than others, and require special construction to attain your desired results and satisfy the discriminating taste buds of chocolate connoisseurs everywhere.

Chocolate pump best practice

There’s more to pumping chocolate than meets the eye—from the material used to make the pump itself, to the speed and pressure of its operation, to regulatory compliance and the maintenance required to keep it in good working condition.


Chocolate Processing at a glance

Whether processing chocolate to sell to confectioners, or making  confections like candy bars, truffles, or enrobing nuts or pretzels, Viking pumps are found —from bean to finished product. The main goal being to produce fine chocolate that melts in the mouth without any grainy feeling. 

Viking pumps come into play once the cocoa beans are ground down into the slurry-like substance known as chocolate liquor. Our internal gear pumps effectively transfer this mixture of finely milled solids consisting of cocoa, sugar, and milk products.

Viking pumps also transfer chocolate through the blending, refining, smoothing, and tempering processes. By design, our pumps are able to handle these more difficult forms of chocolate. This is where our expertise in the chocolate industry really pays off.

Contact Viking Pumps to discuss how we can help with your chocolate processing needs.

We recommend the following best practices to follow when specifying and operating internal gear pumps, in order to optimally handle any type of chocolate product:

  • Cast iron is typically the external material of choice for pumps used in chocolate applications, since any metal particles are easily removed by magnetic separators. Due to the tendency of chocolate to solidify when it cools, a “jacketed” pump is ideal. Ductile iron or steel rotors are used to handle chocolate’s high viscosity. Viking offers cast iron pumps that comply with EC 1935/2004, an EU standard relating to materials of construction designed to come into contact with food substances.

    cast iron pump

  • Hygienic pumps must be used in some cases, such as milk chocolate and finished tempered chocolate. Viking offers a stainless steel Hygienic Series of pumps that all conform to 3A sanitary standards, USDA FSIS standards, and EHEDG compliance for in-place cleaning, in addition to EC 1935/2004 and FDA requirements.

    Hygienic pump

  • Hard bushings should be used due to the presence of abrasive particles in the chocolate. If hard bracket bushings are used, the shaft should be of a hardened material, as well.
  • Food grade (PTFE) packing is preferable in pumps fabricated specifically for processing chocolate and other edible products, as it uses FDA-compliant fibers and lubricants.  O-ring seal and mechanical seal options are also available to eliminate the leakage needed to cool and lubricate packing.
  • Idler bushing lubrication helps prevent product buildup in close clearances. This involves fitting the pump with a drilled idler; whereby, staggered holes are drilled through the idler gear and bushing to more readily allow fresh liquid to reach the area between the pin and idler. Difficult applications may require external lubrication of the idler pin, using a special pump to apply cocoa butter onto the pin.
  • Slow moving liquid, like chocolate, under pressure will tend to pool behind the rotor and can potentially solidify. To prevent product stagnation behind the rotor, grooves can be used to create an internal circulation path for the liquid.
  • No internal relief valve! An internal relief valve is not recommended for chocolate due to its tendency to solidify. During normal operation, there is always some liquid in the relief valve. Stagnant chocolate can set up in the valve and prevent it from opening and performing properly. An external valve or other type of over-pressure protection helps alleviate this problem.
  • Discharge pressure should be kept as low as possible due to abrasives, cocoa butter, and other solid contents of the chocolate. Pressure on the discharge side of the pump should not exceed 100 PSI. Higher pressures will press out more of the cocoa butter and could damage the final product. At higher pressures, the bracket bushing may not receive adequate lubrication. If this area is not well lubricated, the pump can lock up.
  • Pump speed/RPM is one of the most important considerations in the successful handling of chocolate. At higher speeds, it is less likely that fresh liquid will reach the area between the idler bushing and pin.

The right pump for the right application

The next time you need to add a pump to your chocolate processing operations, be sure to contact a Viking Pump representative to learn more about the in’s and out’s of the right pump for the right application. In addition to the tips provided in this article, we can personally guide you to help avoid costly mistakes in pump selection and operation.