I do the inverted method with my aeropress. Put the ground coffee, 40g of water, stir, put 60g more of water. Wait for it to brew. Put the lid, and flip.
As soon as I flip it on the mug, I can hear the water dripping rather faster than I'd like. Is this normal? Shouldn't the water stay in (or at least drip very slowly) until I actually push the handle?
I use a 1:10 coffee to water ratio, with ~1min brew time, and ~20s push. I use grind size 11 on my Comandante.
This will happen if you are using flavored coffee, if you're using too much water relative to coffee, or if your grind size is too large.
Flavored coffee causes this because a big portion of the "coffee grounds" are actually flavoring solids that dissolve in water. When you add water, those solids dissolve, and you're left with not enough coffee to hold back the water.
Too much water relative to coffee can cause this simply because of gravity. More water means more force pushing down on the coffee beans, and that means more water can get through.
Grind size too large is a likely cause. Your coffee simply might not be creating a cohesive barrier to water. Coarsely ground coffee will do this because the coarse grinds leave little gaps where the irregularly shaped grinds touch. Water can flow through those gaps. For Aeropress, you want a grind setting between drip and espresso.
