Fresh tomatoes arriving at the tomato paste production plant in trucks are unloaded into a collection channel (flume) and transferred into the roller elevator which then conveys them to the sorting station. After having been rinsed under a clean water spraying system, damaged and excessively small tomatoes are placed on a reject conveyor and the tomatoes suitable for processing are transported to the milling stage where they are chopped. The pulp is pre-heated to 65-75°C for Cold Break processing or to 85-95°C for Hot Break processing.

In the process of tomato paste production, the term Hot Break means that the fresh tomato is chopped when heated, at temperatures ranging from 85 to 100°C, while Cold Break means that the fresh tomato is chopped at lower temperatures, ranging from 65 to 75°C. The difference between the two products lies in the apparent viscosity, measured in Bostwick centimeters. The Hot Break Tomato Paste is more viscous and therefore denser, and has an average Bostwick viscosity ranging between 3.5 and 6 centimeters, while the Cold Break Tomato Paste is less viscous, therefore less dense, and normally measures from 9 to 16 Bostwick centimeters in viscosity. The HB tomato paste is usually used for ketchup and different sauces requiring a 28-30° Brix, while the CB tomato paste is mainly used for triple concentrate paste at 36-38° Brix, packaged in 500 or 1000 gr cans for domestic use.

The heated tomato pulp (fiber, juice, skin and seeds) is then conveyed to the extraction unit which is composed a pulper and a refiner, equipped with two sieves having different sized meshes. Two products come out of the extraction unit: refined tomato juice for concentration and waste for disposal. On average, the yield is about 95% so 100 kg of tomatoes unloaded from the trucks will produce about 93-94 kg of tomato juice to be concentrated for producing tomato paste. The tomato juice in this storage tank is fed to the evaporator which automatically regulates juice intake and finished concentrate output. The tomato juice inside the evaporator passes through different stages (also called effects) where its concentration level will gradually increase until the required density is obtained in the final stage or “finisher”. Here the tomato paste is automatically extracted via a pump controlled by an electronic refractometer.

The entire concentration process (evaporation) for producing tomato pase takes place under vacuum conditions and at low temperatures, significantly below 100°C. Product circulation inside the various concentric tubular exchangers is carried out by special stainless steel pumps which are designed to ensure that the product is conveyed inside the exchanger tubes at a speed of over 1.2 m/sec to avoid “flash evaporation” thus avoiding to get burnt.

The tomato paste is sent from the evaporator directly inside the aseptic system tank. From here the tomato paste is pumped at high pressure inside the aseptic sterilizer-cooler and then to the aseptic filler, where it is filled into pre-sterilized aseptic bags housed in metal drums. The sterilized tomato paste is cooled down to about 35-38°C before being piped into pre-sterilized aluminum bags housed in special metal or plastic bins via a special aseptic filler.

In terms of commercial descriptions, 28-30° Brix tomato paste and 30-32° Brix tomato paste are named as double concentrate tomato paste where the 36-38° Brix tomato paste is classified as triple concentrate tomato paste.