Hello Mr. Cho,

I have been experimenting with different starch sources to make JMS. I tried tapioca, corn starch, and potato starch. All of them supported microbial growth, but the process was very slow compared to boiled potatoes.

For example, when I blend and incubate boiled potatoes at 26–30°C, thick foam appears within one day. But when I use starch (even after boiling it until it becomes translucent and viscous with no lumps), the foam is still very little even after three days.

I am confused about what might be wrong. Could you please explain why starch does not work as effectively as boiled potatoes?

Thank you very much for your guidance.