Jams
Laboratory Viscometer Application Data Sheet
USE
Jams are spread onto breads, used as fillings in pies and pastries or as decorative coatings on confectionary items.
ISSUE
Traditional viscosity testing with a viscometer and accessory, such as a t-bar spindle, can be difficult as jams often have solid particles (fruit) which can cause large variations in centipoise (cP) values. The R/S+SST and a yield test easily produces two numbers, yield stress value and modulus (slope of line leading up to yield stress), which are used to evaluate the fluids in less than 30 seconds.
Test Equipment:
- Instrument: R/S+SST Rheometer (Soft Solids Tester)
- Geometry: V80-40, V40-20 Vane Spindles
- Software: RHEO2000
TEST METHOD
Controlled by Shear Rate (CSR)
PROGRAM
- One step,
- Start RPM = 0.5
- End RPM = 0.5
- Time = 20 seconds
- Plot = Shear Stress on Y1, Time on X, no Y2
The graph shows data for four different types of toppings. The fig jam has a yield stress just below 1000Pa while the others have considerably lower values. The vane spindle geometry easily distinguishes these four different ranges and allows for a quick pass/fail test.
