I often leave the dishwashing until the situation is dire. Often I give the disgusting dishes a good rinse before putting them in the dishwasher. But sometimes I just toss them all in and hope for the best.
For the most part, my dishwashing machine does a good job. But sometimes plastic items—particularly take-out containers (which I reuse a lot)—get a film of soap stuck to them that can’t be washed or rinsed, or even scrubbed away. It’s like you need to scrape it off with industrial tools. I often just end up pitching them.
So what’s going on here? Is there an issue with soap binding to plastic? Is it more likely if there’s some fat (e.g., dairy, oil, or chicken fat) or protein (e.g., egg white) remaining on the surface?
Soap (and more importantly water) doesn’t shed from plastic like it does from glass.
My first suggestion is that if you aren’t using a rinse aid (Jet Dry etc) then start using one, it may help.
Oddly enough (since I just got a new dishwasher and had this problem), if you are using rinse aid, that may actually be what you’re tasting, in which case you can experiment with adjusting the dishwasher to use less.
That was the case for me. First load, everything totally covered with water. Okay, I guess I do need rinse aid with this dishwasher (yes, it has heated dry, just like my old one).
Second load, with rinse aid, everything dry, grabbed a plastic cup filled it with water and as I took a swig I could see the suds as I moved the cup to my mouth, belgh, tasted like soap.
Did some research, turned down the jet dry to about half. I’ve only run it once and I don’t think I had a lot of plastic in there, but it was mostly dry and didn’t look sudsy. I’m sure I’ll still have to experiment.
ETA, you didn’t mention if this is cosmetic or if you can taste it. If you can taste it and what I mentioned above doesn’t work well, I did see a lot of people talking about running their dishwasher through the quick rinse cycle right after the regular cycle. It adds another 45 or so minutes, but at least all the soap is gone.
I find that dishwashers are utterly useless for plastic items. I’m not sure why - I assume it’s a wetting/surface tension issue - but plastic containers often don’t get clean. Also, they never dry properly (presumably because they don’t get hot enough to evaporate the water).
Hand-wash only for plastic stuff, in my experience.
You will have better results if you rinse them right after using them, and put them into the dishwasher to sit until you run a load. by letting them sit for a few days, you are letting the food dry out and get set onto the dishes. (Actually, most modern dishwashers do just fine without any rinsing at all. And that saves both water & energy.)
Most take-out containers are not designed to be reused – they are made from cheaper materials which don’t stand up to repeated uses. And some, like bottled water, can have problems with bacterial growth in them. Just pitching them is probably the better response.
Let me ask, if you can’t wash, rinse, or scrub it away, what makes you sure it’s a film?
Detergents, especially if you use too much of them, can etch the surface of plastics and glass. The result ends up looking cloudy just like a film, but what is really happening is that the surface of the item has been scratched up.
Be careful not to use too much detergent. If you don’t live in an area with hard water, use less than the maximum recommended. And use a rinse aid, too.
Because it is uneven and tacky/slippery and smells like soap and if I scrape it hard with the tip of a screwdriver, it flakes off like soap would, but it takes too much effort to get it all off cleanly.
I hope this isn’t a hijack, but why is this discussion focusing on dishwasher machines? I find that these sort of oily plastics are very difficult to clean even by hand. In other words, no matter what kind of fat/oil is on the plastic, and no matter how much dishwashing liquid I use, and no matter how hot the water is, the oil rarely comes totally off.
I don’t think “film” is the right word. But when I wipe my finger across the plastic, my fingerprints are all too visible. I want the plastic to be squeaky clean, literally, in the sense that my finger gets some friction from the plastic, and doesn’t just slide across the oil.
I often give up, and use a tissue or paper towel to absorb what I can, and pretend to ignore the rest. Any suggestions?
Speaking for myself, I.focused t on the dishwashing machine because that’s when I get this hard-to-remove soap residue. It doesn’t happen when I hand wash.
I second using a rinse aid, although you don’t have to buy Jet Dry; I use white vinegar bought in bulk from Costco. Also, try using a different detergent–they are not all created equal, and this is one of those cases where I think paying for a brand name (Cascade liquid in my case) is worth it.
I agree that you are using too much soap. I had this same problem, and I now use about half of what I used before. I also use a rinse aid, and that helps too.
I’m only going to keep using the gel soap until I’ve used up all of my rinse aid, which I bought a huge bottle of at Costco. Then I’m moving on to Cascade’s Platinum tablets. I tried them out in my dishwasher, and they do a far better job cleaning than the gel does.
I had the same problem, but then I tried some budget brand of “earth friendly” dishwashing soap that I bought solely because it was unscented, and it works perfectly. (I think the brand name is Seventh Generation? I just buy it by remembering where it is in the store…) I think it’s because it’s basically pure detergent plus a gelling agent, no “dries without streaking” or “good for your hands” nonsense. As a bonus, your plastic doesn’t end up tasting like lemon scent. I use the cheap lemon-scented stuff for regular dishes and the other stuff for plastic.