Check a bag in. 15kg for €15, each way, with Ryanair and Aer Lingus.
What I do is bring a soft bag over inside my wheelie case that's cabin size. One carry on bag so no fees. On the way back I put any beer I've bought locally in the wheelie case and check it in (online in advance) and use the soft bag as my carry on luggage. You could do the reverse.
Make sure to pad the bottles well, though I brought 15kg worth of geuze bottles back from Belgium last night and they all survived.