For quite a long time I am using a south Indian filter. Earlier I used to brew without using the middle small instrument which looks like the one used in a french press for "pressing". It still used to give me a good brew. In few minutes I used to get a fresh brew. I don't know why, but suddenly it is taking longer to finish the brew and sometimes (mostly from the second time) the water doesn't even go down. It just stays in the upper part of the instrument. The coffee powder I use is unchanged and so is the filter. I checked if the pores of the filter are blocked, but that is also not the case. They are all clearly opened. I wash it regularly. I tried using and not using the middle pressing instrument. No effect on the result. So I don't know what's exactly wrong and why this sudden change has happened. One thing that is different is that I have stored the coffee powder for a longer while this time (still not more than half a month). Can it make a difference? Does the powder have a shelf-life? Has anyone faced this problem? How did you solve it?