@Semperfimom welcome back to soaping! I love how soapmaking allows us to customize soaps to our personal preferences.
I personally want more bubbles than I get from 15% CO + 5% castor, which is why I add sorbitol at 1% of oils. It's a finely-powdered sugar substitute, and not much more expensive than using sugar because it takes less sorbitol than sugar to achieve the same level of bubbles. But if folks don't want to have an extra ingredient around, sugar works well, too.
Interesting note from Kenna of Modern Soapmaking about the effects in soap of the ricinoleic acid (from castor oil,) and how the soap
[email protected] numbers are misleading related to castor oil:
Ricinoleic acid is better viewed as a lather stabilizer, where it helps the lather longevity provided by the saturated fatty acids. Ricinoleic acid in soap does not have a lot of lather on its own. I like to think of it as a great supporting actor rather than the star of the show. If a formula contains very little lauric and myristic acid but a lot of ricinoleic acid, the bubbly rating will be really high. The formula won't have the bubbly lather you expect from the rating given because the lauric and myristic are low on their own.
Personally, I simply subtract the ricinoleic content from the bubbly rating to reach a better idea of the size of the lather's bubbles (big fluffy empty bubbles). In doing so, I'm basically adding the lauric and myristic acid content together, which is great because that's the two fatty acids that contribute to that soap quality.