# Reaction of moist egg shell powder and acid?

So I performed an experiment to investigate the effect of fluoride ions on the rate of reaction between egg shells (calcium carbonate) and acid.

When doing this I had a dry sample of crushed egg shells and a sample previously soaked in distilled water which had dried for 3 days but was still slightly moist in a 'gloopy' texture.

When I reacted the moist egg shells with hydrochloric acid they made a frothy mixture of bubbles where the carbon dioxide was trapped in bubbles while the dry egg shells fizzed and the carbon dioxide was not trapped in bubbles.

What could be a reason for the differences in the way the carbon dioxide was trapped?

(membranes were removed from both samples)

I don't think anything chemically has occured. It's likely that the membrane of the dry eggs became rigid and brittle and thus fractured into pieces when the bubbles formed where as the moist membranes would be more deformable allowing them to trap $\ce{CO2}$ bubbles.