Substituting sugar with a liquid stevia concentrate in a cake I have a cake recipe that consists of a dry part, a liquid oil part and eggs. Around half of the dry part consists of sugar. I would like to replace that sugar with liquid stevia concentrate at a very small fraction of the original sugar. If I do that though, then around half of the dry ingredients would be removed from the recipe.

How would I adjust such a recipe? Would I reduce the eggs and liquid oil part proportionally to how much of the dry part has been removed? Anything else that I would need to take into consideration? For example, since the sugar is not soluble in the liquid part, I'm thinking it must also bring certain physical properties to the cake.



I noticed that if I replace the sugar with an erythritol / xylitol blend, then the end result is very similar to the sugar product, so maybe there's a similar bulking agent I could use instead of the sugar? Polyols add sweetness as well, so they wouldn't work in conjunction with the stevia concentrate, it would ideally have to be something neutral.
Use dextrin.

On the theory that dextrin (insoluble fiber) is molecularly similar to sucrose, I made chocolate chip cookies and substituted dextrin 1:1 for all the sugar, sweetening the dough with erythritol (and regular chocolate chips).  I used the CVS brand dextrin which is sold with fiber supplements like Metamucil.  A brand name for dextrin is Benefiber.  It is very much a bulking agent exactly as you request.  It has no flavor.

The dough was the right consistency and the end product was more the consistency of shortbread than a toll house cookie, but they were good.  No GI issues either.