Add several slices of lemon or several tablespoons of distilled white vinegar.
www.stuff.co.nz The ingredients are all safe and can be found around the house: water, distilled white vinegar, baking soda, washing soda, lemons and oranges.
www.pennlive.com Vinegar (dilute acetic acid), especially white vinegar, is also a common acidifier in baking; for example, many heirloom chocolate cake recipes call for a tablespoon or two of vinegar.
en.wikipedia.org Active ingredients in wacky cake include flour, sugar, cocoa powder, baking soda, vegetable oil, white vinegar and vanilla extract.
en.wikipedia.org