Caffenol? No... wrong Soda.

Without planning for it, I went for Caffenol supplies… turned out I got the wrong soda.
The developer is Ascorbic acid (Vitamin C), Washing soda (water free, Na2CO3) and Instant coffe (lots of chemistry)…
Shown is baking soda (“Bikarbonat”, NaHCO3) – which won’t work.

More on Caffenol use in the comments here.