Keto Coffee No Sweetener. Hi martina, i made a keto coffee cake for friends over the weekend and the recipe called for 1 1/2 cups sugar substitute so i used erythritol and it came out awful! When you make the change to a ketogenic diet, you want to pay careful attention to what goes into your drinks, especially coffee. How to make whipped coffee less bitter. I experimented with the ratios of instant coffee, sugar free sweetener and water quite a bit.
