I recently made chocolate mousse with 50g of 100% chocolate, and 2 egg whites. No sugar, sweeteners, or cream added. This resulted in a very stiff and even slightly grainy (but that might just be because my chocolate wasn't hot enough) chocolate mousse. Trying the same recipe with 70% chocolate results in a slightly softer, consistent mousse that is easier to handle and mix during the preparation. It becomes even easier to make when a bit of sugar is added.
The sugar seems to alter the texture of the chocolate mousse to make it somewhat fluffier. How do i replicate the texture of a 70% cacao chocolate mousse when using 100% cacao chocolate without adding sugar? If possible I'd like to make a chocolate mousse without adding cream because I like the lighter feeling of a mousse made with just egg white + chocolate. Do I just need less chocolate in relation to the egg white to make up for the increased concentration of cacao so that the 70% and 100% cacao mousse end up with the same amount of cacao in them rather than the same amount of chocolate?