The pow-starting temperature (T-s) of low-moisture starches (potato, sweet potato, corn and wheat starch) was measured using a capillary tube viscometer under varying moisture content and applied pressure. T-s increased with deacreasing moisture content and applied pressure. There was no significant difference between starch varieties. T-s converged to a temperature Tc (270.9 degrees C) at a pressure P-c. (0.32 MPa). Because T-s was in inverse proportion to the moisture content and logarithm of the applied pressure, it was expressed as T-s = T-c - (a + bW) log(P/P-c). The lines calculated from the equation were in a good agreement with experimental data.