July 14, 2018
Cold-brewed coffee has gained popularity over the last ten years. The principal reason would be that the harsh flavor of hot-brewed coffee is eliminated. This is likely because the various oils, acids, and other aromatic molecules are left in the coffee grounds. Cold-brewed coffee is 60% to 70% less acidic than hot-brewed, which some proponents feel makes it a healthier beverage. Also, home-made cold-brewed coffee will keep, in the refrigerator, for a couple weeks.
Cold-brewed coffee is made by steeping the ground coffee in ambient water. This soak-period can range from a few hours to overnight. This can be compared to producing hot-brewed coffee in a few minutes using boiling water.
Vincent has found an application for our screw presses in the cold-brewing process. The presses are used after the coffee has been soaked. Since the coffee is ordinarily drained through filters, the final pressing increases the yield.
Our presses work only when the grind is coarse. Otherwise, there are way too many coffee fines in the press liquor. Regardless, the press liquor requires further filtration.
Three companies use Vincent presses in producing cold-brewed coffee. After extensive study, it was concluded that the flavor profile did not change.
Throughput rates for our presses has been exceptionally good, even over the high end of the range for a given press. Wedgewire screens with slots which are 0.010″ (250 microns) wide have proven to give the clearest brew. Torque requirements are in the normal range for Series CP and VP screw presses.
The moisture content of the press cake runs 60% to 65%. This is noticeably higher than the 55% norm for coffee grounds in a hot-brewed operation. Still, no free water drains from this waste.
Most Vincent presses are used for processing waste and making animal feeds. For cold -brewed coffee we upgrade the construction to what we call “Vincent Food Grade”:
“The liquid contact parts will be sand blasted; then pits and undercuts will be filled, and spatter will be removed. The stainless surfaces will be passivated with acid compound. Final blasting will be done with glass bead to give a slight luster to the metal. Food grade grease will be used in the factory. If specified, the gearbox will be filled with food grade oil.”
ISSUE #308