It sells for $5.29 at my local Jack in the Box but I got this courtesy of Jack in the Box.
Essentially, the Double Jack is the Jumbo Jack with double patties, the addition of mustard, and more cheese. It serves to highlight recent ingredient changes including Jack's new bun and freshly-prepped tomatoes and lettuce. It also reminds more than a little of the All-American Jack they offered back in 2011.
The lettuce and tomato were fresh but I could have used a bit more lettuce and onion to balance out the beef (but I guess that's what the Jumbo Jack is for). I don't recall having many problems with the freshness of the lettuce or tomato at Jack in the Box in the past but perhaps the fresher prep is meant to provide more consistency.
|No more grill seasoning...|
The new bun isn't as nice as the brioche-like signature bun on the Buttery Jack. Compared to your standard burger bun, it has more of a chewy sheen to it as well as a slightly moister crumb. It's also a little more dense.
On a side note, the pricing is a little bit odd as you can get the almost identical Jumbo Jack with cheese for $2.69 (which also comes with two slices of cheese) at my local Jack in the Box. You would think that the extra patty would generally cost about $1 more but the Double Jack goes for $5.29, which makes the extra patty a somewhat expensive add-on.
Nutritional Info - Jack in the Box Double Jack (319g)
Calories - 830 (from Fat - 520)
Fat - 58g (Saturated Fat - 22g)
Sodium - 1130mg
Carbs - 34g (Sugar - 7g)
Protein - 46g