What is the spicy kick in "Kraft Tangy Spaghetti" box meal?

I love the Kraft Tangy Italian spaghetti sauce seasonings and I just experimented with several of the suggestions listed above. I added some dried crushed red peppers into a blender along with Garlic Powder, Onion Powder, Dried parsley leaves and an off brand "Italian Seasonings" blend of dried herbs and blended them all together. That was a good start, but then I added a little white vinegar and blended up some mushrooms and poured it all into an 18 quart roaster because I needed to make enough spaghetti and sauce for 50 adults. I began with 1 29 oz. can of canned tomato sauce and also added to it 1 14.5 oz. can of diced tomatoes with onion basil and oregano already in it. That was close, but needed to add some pepperoncini peppers about 1/2 of one per the above measurements of sauce. I added a teaspoon of powdered onion soup mix and a drop of Worcestershire sauce a drop of Louisiana hot sauce and 3 drops of soy sauce and then it tasted really close to it, or so much so that my wife and kids as well as my own tongue could not make out the difference. Hope this helps and works for you as well.

I also enjoy reverse-engineering recipes, so here's some thoughts.

I've never heard of this product, but I'd be surprised if it wasn't simply crushed red chili pepper flakes and/or black pepper. For a product like this, it's probably something commodity or inexpensive. Perhaps you've already tried these things...

A way to bisect this might be to search for a jar of pasta sauce that is as close as you can find to the basic flair of the target sauce. Then add things like crushed red pepper or black pepper to see where that takes you.

The box seems to say "just add tomato paste," so it's possible that it's something in addition to spicy-heat, like acidity or umami that you will get from tomato paste. Might be worth adding that, or other acid (like vinegar or Tabasco), or other umami like mushrooms or anchovy. Or even olives...

But if you're going that far, just make Martha's pasta puttanesca! :) It's fresh and simple.

Happy hacking!

After seeing the ingredient list in the comments above, it reads more like onion soup mix or instant ramen noodle packet than pasta sauce! I stand by my blind recommendations! Final notes:

• MSG and HVP are for umami (i.e., monosodium glutamate; hydrolyzed soy/vegetable protein). You can find this stuff at Asian markets, but... I personally wouldn't. :) As I posited above, you can get umami from more "conventional" ingredients, e.g., porcini mushrooms, anchovies, soy sauce, etc.
• Add black pepper and crushed red pepper flakes to your other favorite jar of pasta sauce.
• Abandon ship. Make puttanesca. :)

Kraft Tangy Italian can be replicated using their list of ingredients. Tomato paste and sauce (find your preference in amounts, I like more sauce (or diced or crushed tomatoes) with a tablespoon of paste) , onion powder, garlic powder, celery powder (or celery seeds), sugar (small quantity a must), I don't use the Soy protein, Mono Glu or Food starch...those are stabilizers and this gets eaten... the only thing left is their "SPICE"...it is FENNEL...that is the key to the taste of Kraft Tangy Italian for our family. Careful a little goes a looooong way. Get too much and this stuff is yukky (speaking from personal experience). Get it right and I have yet for anyone to tell the difference! Heat?? have not tasted any heat from the boxed mix but if you want you could add any of the peppers. Cayenne, Paprika, flakes

Let me answer your question. I HAVE recreated the heat and the tang of this sauce. The heat is cayenne pepper powder. The tang is vinegar. Period. Add each and jeep tasting till you get it right. Don't forget to add 1/2 tsp. sugar as well to balance the sauce.