Yes, my 20 PPM colloidal silver is plenty stable all on it's own with no cap due to "zeta potential" which keeps those silver particles apart. All have the same elec charge so they repel each other. That holds them in suspension in the colloid. That works well for 20 PPM but once you get up to higher PPM it just gets too crowded in there for the the zeta potential repulsion to work.
The colloidal silver you made today: same story......... well at least the Cinn Reduced. (Don't know what the deal is with agave??) You could put your Cinn Reduced on the shelf for months & it will most likely look exactly the same. Same if you had made Karo reduced 20 PPM colloidal silver. = Stable.
BTW: Cinn Reduced 20 PPM colloidal silver is also capped automatically. They use Cinn Extract in making higher PPM colloidal silver because it not only reduces it but also caps it. The Cinn Reduced you made today will hold up better against salty acid than uncapped Karo reduced or Maltose reduced colloidal silver. Might hold up fairly well against salty Vinegar. BUT, nowhere near as well as if you re-cap it with gelatin.
Capping probably increases the size of the entire capped particle because the cap on the outside is like a coating. How thick, I don't know but once it is digested off you have the same size silver particle you started with before you capped it.
When making higher PPM colloidal silver the reduction & capping both happen during the electrolysis. IE: you add everything: electrolyte, reducer, capping agent & then start the electrolysis. As the IS is made, it is reduced. As it is reduced the cap is put on the particle. If you are making higher PPM colloidal silver using Cinn Ext. then you just add that along with the electrolyte & then do the electrolysis because Cinn Ext dose both the reducing & the capping all at once.
But remember, you should really learn to walk before you run. Make AT LEAST 5 or 10 batches of 20 PPM Karo reduced colloidal silver. Then make a few batches of 20 PPM Cinn Reduced colloidal silver. After that you can have fun experimenting if you want to. At least you will know what "normal" looks like. When doing experiments I find it useful to make a big batch of IS, then split it into 4 or 5 sub-batches & reduce them all slightly differently.