Not sure if this applies to NZ dishwashers but from this article

https://www.consumerreports.org/cro/dishwasher-detergents/buying-guide/index.htm?EXTKEY%3DAYAHRE03

Skip prerinsing. Most newer dishwashers have a sensor that checks how dirty the water is. The sensor determines the amount of water and time needed to get the dishes clean. But if you prerinse your dishes and the sensor detects little food, the dishwasher gives the dishes a lighter wash, which can leave bits of food on dishes and glasses. Do scrape off dishes and pots, however, before you load them into the dishwasher. 

If I don't pre-rinse dishes before  put them in the machine I cop heat from my wife :-(  But I now wonder if all that water I use to pre-rinse is being wasted since the DW is now not washing the dishes properly.

I just chuck a tablet in the bottom and sometimes remember to fill up the rinse aid.  As far as I was aware the pre-wash is for very dirty dishes.  

usually when I am cooking, once I have done the Mise en place I will either wash or rinse and stack the dishes in the sink, so the dishwasher just gets a short cycle.

everettpsycho: I've been wanting to try this for months since seeing this video and the follow ups hut still haven't managed to get through the bulk load of tablets we got last time. The science of what he's saying makes complete sense, of course soap in both washes will help get the dishes clean.

The real key however is don't block the spinning blades, that's what really ruins your wash as it just stops the water reaching your dishes.

I've found a few of his videos pretty good though, informative enough to understand how things work without going too far in to the deep science of it to lose my interest or understanding.

lchiu7:

Not sure if this applies to NZ dishwashers but from this article

https://www.consumerreports.org/cro/dishwasher-detergents/buying-guide/index.htm?EXTKEY%3DAYAHRE03

 

Skip prerinsing. Most newer dishwashers have a sensor that checks how dirty the water is. The sensor determines the amount of water and time needed to get the dishes clean. But if you prerinse your dishes and the sensor detects little food, the dishwasher gives the dishes a lighter wash, which can leave bits of food on dishes and glasses. Do scrape off dishes and pots, however, before you load them into the dishwasher. 

If I don't pre-rinse dishes before  put them in the machine I cop heat from my wife :-(  But I now wonder if all that water I use to pre-rinse is being wasted since the DW is now not washing the dishes properly.

 

 

Tablets are relatively expensive compared to powder. Even more so when the tablet has more cleaner than is needed to get the dishes clean. We don’t rinse our dishes before putting them in the dishwasher but we normally wash at least once every two days. Drying out of food scraps is not an issue because many of the dishes (e.g. cups) are wet or contain liquid when we put them in - this water keeps everything moister in the machine until it is pumped out as the first cycle.

For a year, we chopped our tablets into smaller blocks and found the dishes washed just as well. The balls in the tablets, which is the rinse aid, didn’t cut easily but it didn’t matter so much because it seems that excess cleaner contributes to the need for rinse aid. So when we reduced the excess of cleaner we also found little need for the rinse aid.

We now avoid tablets because using powder in the pre-wash cycle is very effective. It works well with baked-on and glutinous foods that tend to be the most difficult to remove.

Our current dishwasher always uses a sensor with no user configurable options and it works fine with powder in the pre-wash. Despite the suggestion that the dishwasher might not do the wash cycle correctly, the designers wouldn’t have provided the pre-wash detergent reservoir if it would defeat the sensor getting the wash cycle correct.

There is no after photo of the plates when all the cycles have been completed for comparison in his video?

Also, you can just use a tablet in the main compartment and powder in the pre-wash compartment.

Jase2985:

 

they dont provide much info on their methodology

 

The US Consumer Testing site provides some insight into how they test.

The results are members only but the process is described quite well

https://www.consumerreports.org/cro/dishwasher-detergents/buying-guide/index.htm

CR testers apply a baked-on food mixture to eight ceramic dinner plates and load them into a dishwasher, along with bare plates and drinking glasses to fill the machine. After a normal wash cycle completes, we use imaging analysis to determine precisely how clean each dish is and whether any water spots are present. Then we run a set of clear glass dishware and stainless steel plates through a wash cycle with very hard water and use a spectrophotometer to assess whether any haze or discoloration formed on the dishware and metal.

Plus they stopped testing powders because they felt they were  not as good as tablets and consumers were not interested in powders

The same might not apply in NZ

still doesnt go into how much powder was used, how it was used etc etc

Jase2985:

 

still doesnt go into how much powder was used, how it was used etc etc

 

One would hope they would use the manufacturer's recommended dose

you would like to think so but then you would like to think they post their full methodology