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Writer's pictureLaitram Machinery

Laitram Develops Improved Methods for Pistachio Roasting with Precision Roaster

Updated: Jul 31, 2023


CoolSteam Pasteurization to Pistachio Precision Roasting


Laitram Pistachio Roaster
Laitram CoolSteam Black Precision Roaster

The introduction of the Laitram Precision Roasting system expanded the portfolio of existing tree nut processing including Pistachio Roasting equipment to include roasting alongside the U.S. industry-leading choice for tree nut steam pasteurization, the CoolSteam Pasteurization System.

Our CoolSteam Pasteurization system is built upon low-temperature steam and forced convection. In unison, these two principles create a validated and trusted method for tree nut processors to safely and continuously treat 7 types of tree nuts in facilities around the globe. Over 38 CoolSteam Pasteurization systems are in production today at tree nut processing facilities worldwide to process over 640 Million pounds of tree nuts annually. With low-temperature steam and forced convection, Laitram's CoolSteam pasteurizer produces exceptionally consistent product quality while operating at minimal costs, averaging $0.005/lb. (HALF a PENNY PER POUND). Through continuous innovation, the CoolSteam Pasteurization system is growing to the global standard for steam nut pasteurization.

Laitram Machinery Precision Roasting: Forced-Convection Dry Roaster

Why Make the Precision Roaster?

Well, the no.1 reason our Customer asked for it! Our existing CoolSteam Pasteurization Customers trusted Laitram's culture of innovation, rooted in applying core capabilities to solve customer problems and create value.

With a trusted method for steam pasteurization and identification of a class problem in nut roasting, - we observed product inconsistency in the market, from over-roasted and burnt, to under-roasted and mushy. We set out to leverage our work in forced convection to deliver the Precision Roasting system. The Precision Roasting system is a dry-roasting continuous roaster that uses forced convection to eliminate cold spots and variability when dry-roasting various tree nuts, including almonds, roasting pistachios, cashews, macadamias, pecans, hazelnuts, and peanuts.

Pistachio Kernels roasted on Precision Roasting System exiting belt roaster
Pistachios Roasted with Laitram's Precision Roasting System

From Art to Science, Precision Roasting Eliminates Roasting Variability

As an equipment manufacturer and innovator, we wanted to transform roasting from art to science. Through a series of tests, we found the application of CoolSteam forced-convection technology to roasting could reduce roast time by up to 50% while producing an astonishingly even roast.


How does the Precision Roaster achieve the best roast?


Think of an oven vs. a convection oven or air fryer. Conventional ovens use natural convection. The oven heats the chamber using hot, dry air. The hot air supply from the oven heats and cooks the outer layer of the food. The hotter outer layer of food then heats the inside layer adjacent to it. Essentially, the food cooks itself from the outside in towards the center. Now, in convection ovens, air fryers, forced-convection fans, or another apparatus, are used to increase the airflow and efficiently transfer heat up to 100x faster from the hot oven to the food cooking inside. Because heat transfer increases, the inner layers of food being cooked reach temperature much quicker. Therefore, forced convection more evenly applies heat to reduce cook times.

Cross section of cooked product demonstrating temperature distribution from the center to outside layer using conventional heating versus forced convection heating

By operating with forced convection, the Precision Roaster, for example, for Pistachio Roasters, allows the operator enormous flexibility during processing to lower temperature during roasting due to increased airflow and independently controlled roasting zones. The system is exceptionally consistent; each zone is temperature-controlled, giving predictable and consistent results during roasting.

Through our testing, we determined the power and effectiveness of forced convection roasting and established improved methods for measuring the color and moisture of roasted pistachios. Click the link below to read more about our methods, results, and findings.





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