  We show experimentally that both single and multiple mechanical memories can
be encoded in an amorphous bubble raft, a prototypical soft glass, subject to
an oscillatory strain. In line with recent numerical results, we find that
multiple memories can be formed sans external noise. By systematically
investigating memory formation for a range of training strain amplitudes
spanning yield, we find clear signatures of memory even beyond yielding. Most
strikingly, the extent to which the system recollects memory is largest for
training amplitudes near the yield strain and is a direct consequence of the
spatial extent over which the system reorganizes during the encoding process.
Our study further suggests that the evolution of force networks on training
plays a decisive role in memory formation in jammed packings.
