Why Corelle Dishware is safe for Dishwasher but Pyrex Mixing Bowls are NOT?

[a440]

With all the talk about Corelle Dishware I just wanted to ask if anyone has an answer to the subject question.

I find so many different patterns of the Corelle dishware and I have never seen an "dishwasher worn" piece.  They are always shiny.  I have seen knife marks. The plate however and pattern are still shiny.  

Why weren't the Pyrex Mixing Bowls processed with the same durable "coating" as the Dishware?

I do see many mixing bowls that I pass on because it is obvious they were always washed in the dishwasher.  So Faded!  Some are barely hanging on to their original color / pattern.  

Why did they use a different process? 

I also love Centura plates.  They hold up so well!!!!  Why are they not Microwave safe?

So many questions...... 

 

 

[danemodsandy]

Not a Coating:

Brent:

Corelle is made from a high-quality laminated opal glass called Vitrelle. There are three layers in Vitrelle - the top and bottom layers you can see, and an inner layer you can't see.

Most Pyrex made since World War II is a very inexpensive glass called soda-lime. Soda-lime is tough stuff and resistant to oven temperatures, but it is sensitive to alkali, which will etch it. Automatic dishwasher detergents are alkaline.

So, Corelle and Pyrex are made from two completely different kinds of glass, each with its own good and bad points. Vitrelle is highly resistant to alkali, Pyrex is sensitive to it, and coatings or lack thereof don't have anything to do with it.

Centura's composition (the materials that go into making it) is such that Centura heats up in the microwave - microwaves do not pass through it the way they do with other dinnerware materials. Microwave-safe dinnerware only heats up from the food inside it. Centura heats up all by itself. It can crack or break if it is exposed to enough microwave energy.

This is why Centura was a fairly short-lived product, around fifteen years. When it was introduced, almost no one had a microwave. But beginning in the early '70s, when microwave oven prices began to drop, Centura's lack of microwave safety was a sales-killer.

I hope this answers some questions for you.

 

[a440]

Thanks Sandy!  It all does make sense.

I was noticing that some of the new Corelle is thicker.  Bowls and a few other pieces.  

I think it is great that Corelle is still a big seller.  Some are the new prices per piece are quite shocking!

 

 

[danemodsandy]

Brent:

I don't know what's up with new Corelle, but you're right, new pieces appear to be thicker. It could be a bid to increase durability, though Corelle was already extremely durable. Mine is forty years old!

One more thought on Pyrex vs. Corelle: Corning's intentions were very different for each product. Pyrex was intended to be cheap to buy. It began as borosilicate glass, which is expensive stuff, but Corning used it for a long time. However, after WWII, Corning switched to soda-lime for most Pyrex, because it lowered their cost dramatically, and was easy to color and to print designs on. That made Pyrex "fashion ware," a cheap pop of color in the kitchen that could be replaced without financial repercussions when fashion changed.

Corelle, on the other hand, was a premium product at a high price point. A starter set of four place settings debuted at $19.95 - twice the price of mass-market stoneware at the time. That was a risky gamble for Corning, but it did pay off - the durability of Corelle was perceived by consumers as highly desirable and well worth paying for.

One more tidbit for you - Corelle was introduced with cups made of Centura; the cups were printed with the same design as the plates. Bowls (both the soup/cereal bowl and the optional dessert/berry bowl) were all plain Winter Frost White for every pattern. Only in 1972 did Corning begin making the bowls patterned to match the plates. That was also the year Corning switched the cups to the hook-handle design in Vitrelle; booming microwave sales made it imperative for Corelle to have a microwave-safe cup.

The hook-handled design was the only way a cup could be made of Vitrelle, which starts as a flat sheet of glass and cannot have one piece joined to another. The handle had to be part of the cup, not attached separately. The hook-handled design was advertised as being safe, because your fingers couldn't touch the cup when you were holding it. Even with microwave safety, many consumers didn't like the hook-handled cup, so it was eventually dropped in favor of Pyrex cups, which didn't quite match the Corellle, but which were microwave-safe. Today, World Kitchen doesn't even try that hard - Corelle mugs are Chinese ironstone, with no saucers available.

 

[a440]

Thanks for all the information Sandy!  You do know your Corelle!

When I was growing up I thought it was cheap.  Don't know why.  I did not like Corelle and I HATED Texas Ware!  I love Corelle / Pyrex / Corningware now!  I don't care much for using Texas Ware Plates now, but I do love the Mixing Bowls. Funny how changes everything.

I did a search for Corelle on Youtube and found these very young girls testing the durability of a Corelle Plate.  It took their punishments!

 

 

[a440]

Corelle Dishes: How it's made

Interesting Video...

 



 

 

[a440]

Corelle Domino Effect

Silly video of first ever Corelle Domino Effect!  Reason I am posting it here...if you pause the video at :48 seconds, is that the "Snowflake" Pattern?  It does look like it for my early eyes today.