Electric conductivity for the extracts of the roasted coffee beans (LV 18, 22, and 26) and for the two milk coffee samples with Indonesian AP-1 (LV 20 and 28) and Colombian EX (LV 20 and 28) was measured using an electric conductivity meter CM-60G with a CT-57101C cell (DKK-TOA, Japan). The measurement temperature for the extract solution of the roasted coffee beans was 22 °C and 10 °C for the milk coffee samples.