Friday night I was puking my guts out. I narrowed the list down to either something I ate, or spending the last 2 days knee deep in Monterey’s wastewater treatment plant (WWTP; secondary effluent). The wastewater is an easy horse to bet on, until you hear about the food. For lunch on Thursday I ate 3 tacos azados at a taco truck (affectionately called a roach coach by Gordor) parked outside the Monterey, CA municipal landfill. After that meal I had a slight stomach ache but nothing worse than you would expect from greasy meat and chiles. On Friday I ate lunch from leftovers that that sat out overnight, namely tomato soup with rice made Thursday evening and still on the stove. My guesses are either a virus or bacteria acquired 24-48 hrs previously at the “roach coach” or a toxin/ chemical in the lunch of leftover. The symptoms were vomiting about 5 hrs after eating lunch and lasting for about 8 hrs. Because Gordor didn’t get sick from the tacos I thought the leftovers were the culprit.
After a quick Wikipedia search for “rice disease” I found that most likely what I had eaten was the toxin produced by Bacillus cereus. I vaguely remember my mom telling me not to eat leftover rice, and certainly not rice that has been cooked and left in a warm environment… but when you are hungry you make excuses. My excuse was that by reheating the rice I would kill the bacteria… only to my dismay I learned that B. cereus’s toxin is heat stable!
Take it from me– it isn’t worth a day of vomiting– throw away leftover rice and save yourself the trouble.
Here is what the New Zealand Food Safety Authority says about B. cereus and rice:
There is no way of telling that cooked rice is contaminated. Cooked rice that contains toxin produced by B. cereus will not look, taste or smell off or any different to normal rice. To ensure that cooked rice is safe for eating, a number of steps can be taken to reduce the risk of illness.
• If rice is to be cooked in advance, do not cook too much at one time as large amounts take too long to cool.
• Either, keep cooked rice hot (>60ºC) or cool rice as quickly as possible. Rice will cool more quickly if removed from hot container and divided in clean shallow containers (<10cm deep). Alternatively, cool in a colander under cold running water.
• Cover cooked rice and store in a refrigerator (<4ºC)