As far as I know, there is no “semi-stable” serialization mechanism in Base, unfortunately.
If an extra dependency is not a problem, then MsgPack is simple:
https://github.com/JuliaIO/MsgPack.jl
From the docs:
julia> bytes = pack(["hello", Dict(:this => 1, ['i', 's'] => 3.14, "messagepack!" => nothing)])
42-element Array{UInt8,1}:
0x92
0xa5
0x68
⋮
In your case I think even JSON may be a good choice.