Victory. Across-the-board success. I can't tell the difference at all between my recipe and the official Peet's mix (which they no longer sell).
Recipe first, explanation below:
(makes one Freddo)
2 1/2 Tbsp sugar
1 tsp cocoa
1/8 tsp xanthan gum (Jimbo's sells this)
1/2 tsp vanilla paste (I get mine from Trader Joe's: you want the one with "gum tragancanth" in it)
1 shot espresso
1/2 C milk
1 1/2 C ice
Mix sugar, cocoa, and xanthum gum until blended. Put in a blender with the vanilla, espresso, and milk and whirl until emusified. Add the ice and blend to desired consistency.
So: I've long been searching for the Peet's magic mix. The Peet's Freddo, for those who have not tried the drink, is a thousand times better than a Starbuck's Frappucino. For one thing, it uses real coffee and real milk; Starbucks' blend is made using only powders. But the difference goes further than that. The Peets' Freddo is creamy and fluffy, almost like a milkshake, while the Starbucks Frappucino is more like an icee.
I finally discovered the secret when, completely by chance, I came across a Peets up in Anaheim that was actually selling the freddo mix. I've never seen the stuff for sale before and never saw it again anywhere--this was just a lucky break. I took the mix home and tried it; it was identical to what they'll mix up for you in the coffee shop. All was wunderbar until I began to run out of the mix and discovered that Peets was no longer selling it--not even on their webpage.
So I decided to try to make my own, copying the ingredients list on the back. The ingredients list is as follows:
silicon dioxide (as an anticaking agent)
Xanthan gum is readily available; guar gum isn't. Together, the two interact to form that nice spongey effect I was seeking in the Peet's Freddo. But a little Google research showed that guar gum isn't the only option out there. Xanthan gum apparently has a "synergistic effect" when mixed with several other thickening agents as well, such as "gum tragancanth," the thickening agent used in Trader Joe's vanilla paste.
So voila! The recipe works. And I suspect it would also work used with Splenda instead of sugar, which would be a nice option (Peet's doesn't make a sugar-free Freddo--not even in the coffee shops).
I'll try that one next.