Wakami (a seaweed) is reputed to be something like 5 times more alkaline than any other plant food - dramatically higher, and I have heard that this is because of it's high content of trace minerals. If mineral content is what makes plants alkaline-forming in the body, why not just take a supplement of trace minerals? With this along with a lot of discrepancies among the published lists of what foods are acid and what foods are alkaline, I think that the Science behind what makes a food acid-forming or alkaline-forming is poorly understood. (I do believe in the health benefits of making ones body more alkaline, but I don't always trust the methods described for doing so).
Could it be that mineral content is just one way that a food can be alkaline-forming? For example, certain fruits are always categorized as alkaline-forming, yet no differentiation is made for the organic (high mineral) versions of that fruit versus the non-organic (low mineral content) version of that fruit. (non-organic growing method produce fruits with much lower mineral content).
What I'm leading up to is this: if mineral content is but one way to alakilize, and the other way is something like the easy digestibility of raw veggies and fruits, or some other characteristice of raw foods, then maybe people who haven't had much luck yet with changing the results of their litmus test strips could try the other of these two methods. In other words, if eating tons of raw roods and avoiding obvious acid formers like coffee hasn't helped over time, then maybe seeking out a supplement of some types of trace minerals would help that person.
Ok, I'm really running on here. One other speculation: maybe testing would be in order to see which trace minerals are depleted instead of taking a group of them and just guessing....
By the way, anyone wanting to try Wakami might find it in your local asian grocery store - it comes as a hard dry clump and you soak it for an hour or so and then simmer. Tastes like very bland seaweed. I've only tried it a few times so far.