I've just done 4 120ml bottles forever. More recently I added a 250ml bottle to that. It doesn't take long to mix the base. I'm usually not so lazy about it....LOLHow much base do you usually mix? Last time I made a premix I went all out and made a litre and I am surprised at how fast that has actually been used up. Premixing saves so much time and effort for me....Should have started it long before I actually did....