I primed my 500ml PET bottles and 568ml magners bottles with 1.5 Tate and Lyle sugar cubes from Tescos. 98p for 500g packet. The PET bottles are brick hard after a week. The 330ml tester bottles, I used 1 cube. I opened one on friday and it was nice. Gonna test another tomorrow and if fizzy enough, I'll put the rest in cold storage.
I'm going in to Wilkos today to buy their lager with the free brewing sugar.
BTW the cubes went in the PET bottles no problem, but the glass bottles have smaller openings and the cubes had to be halved in two. I got a new FV so will now batch prime. Tescos are selling a FV for £7.26 with no lid.
Gary.