I’d like to specify that this hydrogel is merely a gelled gelatin in distilled water.

Thanks.

Dear Christhian

I suggest weighing the sample, determining its volume by displacement using an organic solvent that is immiscible with water and that has a density less than 1 g/cm3 in your graduated cylinder, and then calculating bulk density.

A density balance kit will be more accurate

https://www.mt.com/ch/en/home/applications/Laboratory_weighing/density-measurement.html

but the first method should give you a good approximation.

Best Regards

Deon