What's the difference between the flour in the blue bag vs the red? I'm not even sure which one I have since my local Italian shop re-bags it, but I've seen the red bags in the store, so I kind of assume that's it. I've used it with great success in making pasta, but I'm thinking of trying pizza dough. The blue bag is labeled "Pizzeria Flour", but the red bag also claims that it is good for pizza. What's the difference?
Caputo Rosso (red) might have a slightly higher gluten content (~12-13%) than Blu (blue) (~10-12%) and higher stability. But mostly the blue one is just more of a niche product meeting the highest standards for traditional Neapolitan pizza.
Here are spec sheets directly from their web site:
And since they both say ideal for pizza - nothing can go wrong ;-)
And if you don't know what the differences in stability times mean ...
For now, you'll be ok with either. And unless you noticed a price bump, you have the Red (the STG certified Blue are at a slight premium).
In simple terms, the Red is more for making quick thin crust pizza (romano style) run at 720°F whereas the blue is better for thicker rimmed (Neapolitan style) run at 900°F. That's why they both claim 'good for pizza'.
The Red you can do what you like with and even roll with rolling pin and no eyebrows are raise.
The Blue on the other hand is typically kneaded quite well and let rest in various (trade secret) positions for about 3 days (yes, days). It is then 'opened' by hand in a particular way and cooked to show leoparding blisters and all in a fierce oven.
You can still make Romano style with the Blue, but if you did everything right for Neapolitan style and used the Red type you'd get a harder rim. To some people, that's like serving them a well done steak.
There is so much confusion when people don't call the Caputo flours by their real names. There is no such things called Caputo "Rosso" or "Blue". This is what everybody wants to call them, and it leads to confusion.
Caputo has a flour called Pizzeria that comes in 55 lb (25 kilo) bags which happen to be Blue. They also have a small blue bag that is 2.2 lbs (1 kilo) packaged for store shelf retail that is called Confezione.
Then they have a flour called Rinforzato which comes in 55 lb bags, and another called Chef's, which comes in 2.2 lb bags packaged for retail. Both of these come in Red (Rosso) bags.
So when you are talking about Red vs Blue, It's hard to tell what you're talking about.
I'm not sure if the Confezione is still available in the US, but it used to be, and may still be.
As far as speculation about whether or not the Chef's is really just a smaller bag of the Pizzeria or the Rinforzato or something different than either is largely speculation.
All of the above flours are 00 flours. That means that it's ground extra fine (as most of you probably already know, but just in case there are some people new to it)
There is a new type of Caputo Flour that has been out for a shorter while. It's called Pizza a Metro. It comes in 55 lb bags. The touted benefits of this flour is that it's milled/blended for a specific type of pizza called Pizza a Metro (Pizza by the Meter), which is popular in Rome and Sorrento, and works well for temperatures around 700°F.
Wood fired pizza is usually cooked in an oven around 900°F.
I've got some information on this at http://brickovenbaker.com/caputoinfo, and there should be some links in that content to some other discussions about the differences in the flours. In one of the blog posts, a food scientist named Joe goes into differences at a technical level in the comments section, and claims that each of the flours are distinct flours, and that the smaller versions for packed in 1 kilo bags for retail are not the same as the restaurant sized bags, even though people have been claiming that the Chef's is the same as the Pizzeria, and others claiming that it's the same as the Rinforzato. What makes it even more amusing is that two people got different answers directly from Caputo in Italy when asking them if there was a relationship between the Chef's and the other flours, and food scientist Joe said they are both wrong.
Full Disclosure: The link above goes to my blog and I happen to sell Caputo flour on my site. I'm not the best resource for all of the technical details, I don't speak much Italian, and I just want people to call the stuff by their real names because the colors used on the bags does not relate to what's in the bag as far as I know.