Weird. Any chance your oven is not holding temperature?

I have had this same thing happen to me twice over the years -- but I cannot explain why. I'd guess it was caused by the wrong combination of temperature and humidity/moisture -- both being too high.

Johnliu, no. The temperature is fine. They did soften completely. They just didn't melt! But the next batch did. :)

PM, I am relieved to know that it's happened to someone else since I felt like I was sucked into the twilight zone. I don't think it was a humidity issue here, as it's been hot and dry, and there hadn't been anything in the oven for a couple of days so I don't think it was residual moisture there.

The second batch was normal. I could see the chocolate melting through the window. It could have used another ten seconds in the oven for optimal smeariness (difference between getting a sip of water at the table and hovering over it like a nervous mama bird), but it was fully in the range of normally melty.

Just knowing that it has happened to PM makes me feel better. I wonder if there's a manufacturing error? Like the wrong amount of fat or moisture? They tasted normal, but I'm not a trained chocolate chip taster. All I can say is that the couple I tasted had that oily feel that chips do, and weren't dried out or anything, like old ones.

I've had it happen once or twice in the past with recipes too. I think it may be related to moisture/tempering - the chocolate seizes.

I can't help you with your issue Plllog, but I have to say that I love reading your posts. They're a delight to read. Very expressive. :-)

Thanks for the suggestions, All. I appreciate your posts! An offline friend I saw this morning told me something which I looked up, and I think she might be right. Usually when you talk about chocolate seizing, it happens after it melts. Going by what you've all said about the humidity/temperature, and what chocolate is like when it seizes, I'm thinking that it's a matter of hitting that once (un)sweet spot, where the chocolate skips the melting and goes right to seized. Seized is what happens when it's too hot, so knowing the oven was accurate, or if anything cool from opening the door, I'm guessing that there's a certain point where there's something akin to a triple point for it, where the moisture is off or something, and it just seizes.

Or something like that.

Lucky I bought extra supplies. I now have 3.5 qts. of the good stuff crowding my fridge. :) Thank-you all!

Jasdip, thanks for the kind words. Now I have a happy-face to take on yet another trip to the store!

JC

happened to me today. chips did not melt in the oven at 350 for about 12 min (I was melting chips on store bought shortbread) .... so I put them in the microwave. ... 30 sec... another 30 sec... the cookie almost caught on fire.......... still no melting of chocolate.... I'm throwing them all away.

It was undoubtedly a moisture issue. The first batch seized because there was moisture in your oven....but by baking the first batch you drove it out and the 2nd batch was fine

This happened to me. I used butterscotch and milk chocolate chips to make a nice spread. Neither one would melt. I followed the recipe the same as I always did. I did a web search and found that many others have had this problem. Nestle changed the recipe so that they could ship to warmer climates. My chips were not past the expiration date. No moisture was present. The heat was not any higher than any other time I made my recipe. Looks like I am going to switch.

I have been using Great Value brand chips from Walmart. They taste good and get all melty melty. Cheaper too!

Nestle changed the recipe so that they could ship to warmer climates

FWIW, I grew up in FL and even before air conditioning became common, Nestle shipped to warm climates. Ditto AZ. That is definitely not the reason. Some things, like mallomar-type cookies, used to be seasonal because of melting, but chocolate chips, never.

I ordered some Brazilian chocolate from a company in PA, and their web site said that they would not deliver to places where the temperature was over 78°, and this was also written on the delivery box. It was well over 78° in Brazil when I bought the same chocolate there, but not in the store.

According to Bon Appetit, chocolate chips have less cocoa butter as well as stabilizers and preservatives that help them maintain their shape while baking.