Notes Modified Caffenol C-L with baking soda and caustic alkali: Caffenol C-L is a version of Caffenol using reduced amounts of chemicals and is mostly intended for stand development. The Caffenol C-L (B) and (B2) formulas were created on the basis of Caffenol C-L to include alternative (and possibly more consistent) source of alkalinity than sodium carbonate (washing soda). Sodium carbonate is known to exist in three forms, anhydrous, monohydrate and decahydrate. Commercial packages of it do not always provide a clear indication which form of sodium carbonate is included, however, required amounts of anhydrous and decahydrate form will be very different. Besides, there is a recent trend to replace washing soda in the supermarkets with sodium percarbonate, which is unsuitable for making up a developer. The same applies to vitamin C, which is often sold with other undisclosed additives, while sodium ascorbate in powder form is more consistently pure. The resultant solution has exactly the same properties as originally formulated Caffenol C-L.
It was accidentally found that certain coffee varieties, such as Maxwell House Original Roast, provide clean negatives with no stain and no tanning in these recipes. However, this note should not be construed as endorsement of a particular coffee brand.
Special thanks to Alexandre Kraev for this formula.