This topic really made me curious

So I decided to try the simple recipe first:
2 spoons of washing soda in 300ml water (25C)
5 heaped spoons of the cheapest instant coffee
mixed
waited a few minutes for air bubble removal.
The I dropped a film of Rollei Retro 100 (APX-100) in it. I shot it at EI 25-100. Wash with tap water until clear water came out, regular fix&wash.
EI100 was very thin, correct EI seems to be around 25 with this recipe, although the 50 shots were not too bad at all...
Scanned at 3600dpi with my optic 7200, no adjustments.
The positive image:
The negative image:
Off course the negative is a bit boring, so I decided to adjust it from RGB to B/W using the brown colour of the positive image as a tint:
I must say that I was quite amazed in a positive sense
I also have a question. I read somewhere (I think in this topic) that vitamin C can be used to increase speed. Sound good, but does anyone know whether it also increases base fog? And do you use regular pharmacy-vitamin C, without caring about the other ingredients in this "consumer product", as I believe it's not pure vitamin C what they sell?
To close the post, here are a few more:
Positive:
Negatives:
(gossen sixtomat, the light meter which is easy enough in use to explain to a 3-yr old

- unfortunately, he is too young to read the numbers on the scale, otherwise I would have a nice talking light meter)