After my son decided to pour a substantial amount of uncooked rice down the bathtub drain, I find myself in the situation of removing it.

After trying some common methods - to no avail - I thought I could resort to chemistry. Specifically, I thought about dissolving (hydrolysis) the main component of rice (starch) by means of amylase (possibly bought in a shop, not salivating over the drain).

Would this be a good solution to unclog the drain? Under what conditions should I operate to achieve the result hoped? Would there be a better solution?

As you might guess, I'm not a chemist.


1 Answer 1


The problem you'd face using any chemical to dissolve the rice is that rice forms a thick gelatinous surface coating as it dissolves, so that it would take an extremely long time for the amylase to penetrate... perhaps months or years. You'd be better off using some of the standard mechanical drain-cleaning techniques:

Note that augers and snakes can scratch sinks or toilet bowls, and that water-pressure cleaners can cause pipes to come apart.

N.B. If you've already poured a potentially dangerous cleaner into the drain, remove it safely before trying anything else!

  • 1
    $\begingroup$ I'll emphasize the point about safety. The various liquid drain cleaners usually contain strong lye compounds and they are extremely caustic. Getting them on your skin or in you eyes would be very very bad. $\endgroup$
    – MaxW
    Commented Nov 16, 2016 at 6:05
  • $\begingroup$ Thanks for listing other techniques: no 1 is not really feasible unfortunately (my preferred if we were talking about a basin sink) and I'm not super keen on option 4 for the reason you have already described. I guess I'll go with option 2/3 and give up the amylase plan for the time being! $\endgroup$
    – Jir
    Commented Nov 16, 2016 at 16:49

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