I use a Keurig single-cup coffee brewer, but it's obviously more cost-effective and tastier to use the My K-Cup filter adapter to brew my own fresh-ground coffee instead of using K-Cups all the time. Plus there's less waste.
The main problem with this method is that it's hard to get a consistent cup of coffee. Sometimes it's too weak, sometimes it's too strong. Sometimes it causes enough pressure that the Keurig thinks it needs to be descaled even if it doesn't, and ends up making a very strong cup that's not full.
I've been playing around with it a little bit, and I think I've found a pretty good method that is mostly consistent, doesn't cause the pressure problem, and gives about the right strength. You can obviously still choose your cup size based on whether you want it to end up a little weaker or stronger.
I start with a medium grind. You don't want it too coarse (like in French Press range) or too powdery. Somewhere in the middle is pretty good. Mine leans more towards coarse than fine. It helps (as it does with any coffee brewing method) to have a good grinder that gives a fairly consistent grind size, but you should be OK even if you have a cheap blade grinder, you just won't get optimal results.
The secret is to pack the coffee down a little bit (not too much) by tapping the filter on the counter, but also leave space at the top of the filter. If you don't pack it down at all, the water will flow right through and you'll end up with a weak cup. If you pack it down but pack it too full, you'll have the pressure problem. The Keurig will think it needs to be descaled, and it won't brew a full cup because of the pressure.
So I've found that filling it about to the lip, and then tapping it on the counter a couple of times gives me a good result. I end up with about an eighth of an inch of actual visible mesh in the filter above the coffee grounds, which gives it a little room to spread out so I don't have the pressure problem, but keeps it compacted enough that it extracts fairly well.
June 5, 2012