I can check it tomorrow with more coffee, but from the looks of it easily fits 30g. The pic below is 20g of coarse grind in the dripper before and after brewing I did today. If the coffee is super fresh and dark, the bloom may rise higher, so it would need to have more room above. But my feeling is that it can go 30g. But the higher the coffee bed, the longer it will take to finish brewing. DEEP27 with 20g dose 7M grinding took me 5 min. The V60 with 25g dose at 6M grinding took me over 10min to finish. It is designed to be a 1-cup brewer. I have not found an "official" recipe for this dripper, but the CAFEC website and video use only 12g of coffee with 150ml water in this dripper. I don't think I will be using more than a 20g dose for most of the recipe.