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I was arguing with my wife over which dishwasher program to use. I want to use the eco program because it is most environmentally friendly, but she countered that the long program (3:30h) puts more strain on the dishes and results in them having to be changed more frequently. Also she is attached to her dishes. Therefore she would rather use the short program for 0:30h. I imagine it is difficult to calculate the exact environmental impact of the dishes being used out by the dishwasher, because it depends at what point of wear the person would change the dishes.

But I want to question my wife's premise that the eco program is worse for dishes. It does take longer and the dishes are probably exposed to more high pressure water streams. But my google search shows that most of that time is used to 'soak' the dishes. Furthermore the eco mode can use lower temperature for washing and drying and that is probably also good for the dishes. So my question is: Which dishwasher program is best to conserve the plates?

(I'm new to this stackexchange, I hope this question is appropriate here. Please tell me how I can improve it to fit here)

findusl
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    What kind of dishes? I mean, these are usually from pretty hard and sturdy material. Hard enough that some water stream at relatively low pressure (let alone soaking) is going to be able to do any damage at all. By (anecdotal) example: my grandma has used a dishwasher for about 40 years now on the same dishes. The only (visible) damage is from dropping them or othar abbrasive actions, not from the dishwasher. I.e. the question is based on the premise dishes will detoriate by washing them, but is that really the case for your particular dishes? – stijn Apr 03 '21 at 19:05
  • @stijn Good point. We have ornamented dishes with colourful ring and painting in the back. – findusl Apr 04 '21 at 12:24
  • Paint might indeed wear out. But have you checked your dishwasher's manual? IIRC some of them actually mention estimated water and electricity usage per program. Could just as well be the 30m program uses in fact less than that ECO mode (though might also clean less good). In whih case it's almost best of both worlds (assuming shorter = less disch wear as well). – stijn Apr 04 '21 at 16:16
  • Do you know what the actual differences between the programs are? I suspect the short program uses higher temperatures. – LShaver Apr 07 '21 at 16:31
  • @LShaver The buttons show 50°C for the eco program and 45°C for the short program. After the comment of stijn I have tried to find some more information on the differences, but I turned up blank. – findusl Apr 07 '21 at 18:55
  • Interesting. If your dishes come out clean when using the short program, it seems like that one might actually be best. – LShaver Apr 07 '21 at 19:24

2 Answers2

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The manual should tell you how much power and water each uses. Dishes are either OK indefinitely on either program, or at risk of damage on both.

On mine, the quick wash (30 minutes at 65°C) uses less of both than the eco wash (over 2 hours at 50°C). But a lot of that comes from the lack of a drying cycle; in winter my dehumidifier has to work harder to clear the steam. The quick wash is also more likely to result in rejects, especially if I've been baking - so that wastes space in the next load, increasing the power and water use, including in the manufacture of detergents.

As for stress on the contents, the chemicals are the same, so it becomes a question of whether longer and cooler is better than shorter and hotter. Certainly some things suffer at high temperatures, suggesting the cooler eco program. Anything marked as dishwasher safe should be fine at either temperature; I also put non-stick pans and wooden spoons in with no ill effects. As your quick program is cooler than the eco program, it's likely to use less heat, less water, and be less likely to damage anything. It's also quite unlikely to be as effective, perhaps meaning you need to pre-rinse or load it less full.

If her precious stuff isn't marked as dishwasher safe, the bets thing to do is save it for special occasions and wash it by hand, though hand washing uses far more water and energy.

Note that where I am, dishwashers are cold-fill only. Hot-fill dishwashers, where they still exist, use far more water, still use nearly as much power unless the hot pipe is very short, and leave hot water sitting in the pipes afterwards.

Chris H
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  • Where I am only cold-fill dishwashers were available until very recently. Our new dishwasher has cold + hot inlets, and I consider that a decided advantage (at least if renewables are used for the hot water supply). I may add that here, any hot water cooling in the pipe (which will just the same happen when hot water is used at the kitchen sink a few cm besides the dishwasher) will just offset the heating of the house during heating season. When it is so hot that we take care not to let the house heat up too much, there is OTOH for sure sufficent sun for solarthermally heated water... – cbeleites unhappy with SX May 24 '23 at 11:11
  • Wrt to pipe length influencing the actual temperature of the water arriving in the dishwasher, circulating lines for the hot water supply have been the standard here for decades. The dishwasher uses the hot inlet only for the cycle parts where it would otherwise heat any supplied cold water, and I don't see where the idea that it would use more hot water than otherwise cold water comes from!? (It's anyways not the case for ours.) – cbeleites unhappy with SX May 24 '23 at 11:16
  • That being said, I'd also tend to think that the choice of the dishwashing chemicals may have higher influence here. You may be able to find chemicals that are less corrosive on dishes, but if the reason behind all this is to be eco-friendly you'll need to check carefully what their properties wrt. wastewater treatment are. Another option would be to lower the dose of dishwashing agent. – cbeleites unhappy with SX May 24 '23 at 11:48
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    @cbeleitesunhappywithSX solar thermal changes things, certainly. And if that leads to modern designs having hot and cold fill, it could be good. My point about water consumption was that the water-efficient designs on the market are cold fill only - perhaps with hot-fill coming back this is no longer the case. – Chris H May 24 '23 at 12:08
  • As for secondary circulation, it's rare here, even though we need to heat our houses for about half the year. Even with insulation it still heats the rooms. – Chris H May 24 '23 at 12:09
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    And detergent choice could absolutely have an effect, but it's not clear that eco-brands will be better than mainstream brands. For example if the eco brands don't use enzymes (some do, some may not), the other ingredients may be harsher to make up for it. If you can easily get powder detergent, you can reduce the dose. I have trouble getting anything other than PVA-wrapped tablets without a trip to a different supermarket - and when I cycle there I'm already bringing back as much as I can get on the bike so I can't stock up (also @cbeleitesunhappywithSX) – Chris H May 24 '23 at 12:14
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I'm using eco dishwasher program which takes about 3h including drying and noticed that with time some of the dishes started to lose small parts on the edges.

My guess is that it relates to the combination of dishwasher pods' aggressiveness and drying.

So, I've discovered eco-friendly dishwasher pods (my article) and started using them. In addition, started to turn off the dishwasher at drying stage to let the dishes dry naturally.

So far, didn't notice more dishes becoming broken at the edges.

But, I believe the materials dishes are made from play an important part as well because some dishes never broke, only specific ones from the same lot.

rokpoto.com
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    Eco-friendly and plate friendly are not necessarily the same. E.g. sodium hydroxide or - carbonate are very effective for breaking down protein in the food remainders, and they are of very low concern for the wastewater (the small amounts needed are easily neurtralized and/or buffered by the organic acids in wastewater, and the microorganisms in biological wastewater treatment like slightly basic conditions). But they are comparatively corrosive to glass and porcelain (e.g. glazing going dull, for chipping I'd suspect rather mechanical reasons). – cbeleites unhappy with SX May 24 '23 at 11:29