Mysteriously greasy silicone bowl

October 4, 2012 7:05 AM

Why would a silicone food bowl, used mainly for hot soups and oatmeal, eventually feel greasy, even after washing?
posted by SillyShepherd to Grab Bag (10 answers total)

I've had this happen before.... usually washing it twice in a row fixes the greasy feeling for me!
posted by Grither at 7:07 AM on October 4, 2012 [1 favorite]

Some of my silicone stuff has developed mysterious greasy films before (now that I think of it, this was also dishware primarily used for boiling-- hope the grease is something deposited on it, and not mystery plasticizers leaching out.) In that instance, washing with a slightly higher-power cleaner containing a mild abrasive-- IIRC, Comet--did the trick.
posted by Bardolph at 7:19 AM on October 4, 2012

This happens to me also. My theory is that as the piece ages, the surface becomes rougher and provides more nooks and crannies for the grease to hide in.

My other theory is that there are some fats (not sure which, but like a certain level of saturation, or a certain chain length) that are not impressed by silicone's slipperiness. In other words, they stick to silicone the way other greases stick to other kinds of dishes. So you need soapier water and more physical movement to get those grease molecules to break free of the silicone.
posted by gjc at 7:29 AM on October 4, 2012

I did a bit of a google search, and the leading theory is that the silicone is getting too hot and starting to break down. I kind of doubt that theory, though, as they are extensively tested. Are you washing them in the dishwasher? If so, my hypothesis is that soap residue is not fully washing off. Try washing with a vinegar/water solution. You also might find this article interesting -- he's talking about ice-cube trays, but depending on your water type might apply to your bowls too.
posted by DoubleLune at 7:30 AM on October 4, 2012

I don't have a theory as to why, but I've definitely noticed that you can't just sponge-wash silicone dishes with a normal amount of soap the way you would, say, a coffee mug. The only thing I've found effective at de-greasing silicone stuff is putting a small amount of dish soap directly on the offending item, making sure to coat the surface very well (use hand or cloth or sponge), and then rinsing under hot water until you can feel the greasiness go away. That said, I don't actually do this every time, especially if the silicone thing is going to be used for the same type of food next time post-washing. Normally I just wash normally and do a "sniff test" -- as long as it smells clean, I don't worry about it, unless I'm having an especially anal-retentive day.
posted by aecorwin at 9:01 AM on October 4, 2012 [1 favorite]

I have a crock with kitchen implements in it on the kitchen counter. I put clean, grease free silicone spatulas in it and in a week, they have a greasy film on them. I don't cook much and rarely with oils/butter, so I don't know where that stuff comes from! I always rewash them before using them again.
posted by cecic at 9:29 AM on October 4, 2012

I think for some reason the fats that become partially emulsified by dish soap still cling. Best solution I've found for a Silpat is a brief soak in diluted ammonia followed by another wash with regular detergent and multiple hot water rinses.
posted by slow graffiti at 12:02 PM on October 4, 2012 [1 favorite]

Response by poster: I ended up coating it with dish soap and sticking it in a drawer for now. I'll rinse it in a couple of days and see how that goes. It's a cup that folds flat accordian-style, so if that provides crevices for fat to hide in, that's a possibility.

I had the plate that folds down, and after using it in the microwave a few times, the plastic bottom started to bubble and melt. This is a product marketed to campers and supposedly heat-resistant.
posted by SillyShepherd at 6:27 AM on October 7, 2012

Response by poster: I rinsed it this past week, and it still felt kind of sticky, so I filled it with water and microwaved it to boiling, then dried it out as best as I could and stuck it back in the drawer. I think, because it has the accordion-like folds, that grease does find its way into micropores, or something. I haven't had this extent of problem with any other silicone products.
posted by SillyShepherd at 12:25 PM on November 18, 2012

Response by poster: I also know that the GoobToob website has a list of products that are not recommended for use with GoobToobs. It could be that something I heated in the cup wasn't the best for silicone.
posted by SillyShepherd at 12:28 PM on November 18, 2012