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Thermador Star Sapphire Dishwasher Test (Reviews/Ratings/Prices)

March 29th, 2019 | 3 min. read

By Steve Sheinkopf


According to Thermador, you can now wash up to five loads in 20 minutes each after a 20-minute prewash with their new dishwasher.

With the average cycle of a dishwasher being 2 hours plus, it would save you a ton of time with this new technology. 

Thermador Speed Test Parameters


You also have probably noticed your dishes and especially plastics not dry in your current (less than 10-year-old) dishwasher along with greater cycle times.

So the Thermador Star Sapphire and its new 20 minute capabilities could be intriguing.

In theory...because it's just a theory until it is tested.

In this video, you will see three tests of this 20-minute claim. We washed heavily soiled dishes, then baked the stains in a microwave.

For the truly acid test, we then refrigerated the stains so they would congeal. It's a $2,799 dishwasher, we wanted to see how it would perform in the absolute worst conditions.

After the first wash, we then thought to read the instruction booklet. On page 29, it states, “only for lightly soiled dishes.”

So we went back to the drawing board again for a total of three tests. Each test was surprising and worth watching.

The results will perhaps change your mind on whether to consider this dishwasher.

In this article, you will learn about Thermadors new technology and you will see the product being tested 3 times. Then you will conclude on whether the Star Sapphire is worth considering.

What is Zeolite and How Does it Speed Drying?

Zeolite is a naturally occurring mineral from volcanic ash. It is worth the Wikipedia search because it has been used to clean nuclear spills like Chernobyl. It has also been used in supplements as well.

Specifically, Zeolite is packed in the back of the dishwasher. It is reputed to increase heat and absorb moisture to aid in the drying process.

Most dishwashers do not have a real dry cycle anymore, just JetDry and residual heat from the hot water wash.  

So wet dishes and plastics are a common issue. A 20-minute cycle with an effective dry would be the new far.  

Zeolite will also be introduced in less expensive Bosch dishwashers later this year. BSH Home Appliances Corporation, Thermador’s owner, believes Zeolite will revolutionize the industry and how you wash dishes.

So we figured it was worth a test.

The Test: Does the Thermador Sapphire Wash and Dry in 20 Minutes?


We performed our first test using heavily soiled dishes with different combos of caramel, hoisin and Sriracha sauces. Then we rewashed those dishes after reading the instruction booklet. We also washed with lightly soiled dishes as well.

You have to remember to heat the dishwasher up 20 minutes before the wash cycle. It does illuminate the floor when you are ready to wash.

Here are the visual prompts for the different functions.

  • Warming
  • Rinsing
  • Finished

However, the tests were interesting and worth watching.

Star Sapphire on Lightly Soiled Dishes

For lightly soiled dishes, ketchup was spread on each dish to varying degrees along with some loose strawberry jelly.

Results: The dishes were hot. Other than one plate being a bit wet, the cycle did what was advertised. It washed and dried in 20 minutes.

Star Sapphire on Heavily Soiled Dishes

This test was performed before reading the instructions.

Result: The dishwasher washed OK. All the sauce was removed except the baked on caramel from the Snickers.

Result: After the second wash, it did a pretty good job.

Should You Buy the Thermador Star Sapphire Dishwasher?

This really depends.

First, the dishwasher does take longer to heat than 20 minutes by roughly 5 minutes. You also have to remember the “Star Speed” cycle is not designed for heavily soiled dishes in 20 minutes.

However, after the preheat of 20 minutes +, you could wash heavily soiled dishes in about 40 minutes. This is still far less time than an average dishwasher with better results.

$2,799 is the highest price for a residential dishwasher, even higher than the $2,599 Miele Diamond. You will receive a $1,399 credit with other qualifying Thermador cooking equipment.

At $1400, you should buy this dishwasher if you are indeed buying other Thermador appliances. It is far better than any other dishwasher at $1,400.

At $2,799, you are buying the fastest dishwasher on the market with a compelling new technology. It will wash and dry in 20 minutes after the preheat. The drying will be appreciably better as well.  

Is that worth $2,799?


Bosch has introduced Zeolite in their 800 series dishwashers starting at $1149.  You don't have the 20 minute wash and dry and as many cycles, but you still have the capabilities of the Zeolite minerals in drying

Free Dishwasher Buying Guide

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Steve Sheinkopf

Steve Sheinkopf is the third-generation CEO of Yale Appliance and a lifelong Bostonian. He has over 38 years of experience in the appliance industry, and he is a trusted source of information for consumers on how to buy and repair appliances.

Steve has also been featured in numerous publications, including the New York Times, Consumer Reports, The Boston Globe, Bloomberg Radio, the New York Post, The Wall Street Journal, and Entrepreneur, for his knowledge of how to buy appliances and appliance repair.

Steve is passionate about helping consumers find the best appliances for their needs, and he is always happy to answer questions and provide advice. He is a valuable resource for consumers who are looking for information on appliance buying, repair, and maintenance.

Despite being the worst goalie in history, Steve is a fan of the Bruins and college hockey, loves to read, and is a Peloton biker. The love of his life is his daughter, Sophie.

A Note About Pricing

Pricing on this blog is for reference only and may include time sensitive rebates. We make every attempt to provide accurate pricing at time of publishing. Please call the stores for most accurate price.