  Despite the great progress of current cosmological measurements, the nature
of the dominant component of the universe, coined dark energy, is still an open
question. Early Dark Energy is a possible candidate which may also alleviate
some fine tuning issues of the standard paradigm. Using the latest available
cosmological data, we find that the 95% CL upper bound on the early dark energy
density parameter is $\Omega_{\textrm{eDE}}$. On the other hand, the dark
energy component may be a stressed and inhomogeneous fluid. If this is the
case, the effective sound speed and the viscosity parameters are unconstrained
by current data. Future omniscope-like $21$cm surveys, combined with present
CMB data, could be able to distinguish between standard quintessence scenarios
from other possible models with $2\sigma$ significance, assuming a
non-negligible early dark energy contribution. The precision achieved on the
$\Omega_{\textrm{eDE}}$ parameter from these $21$ cm probes could be below
$\mathcal{O} (10\%)$.
