title_body: Purpose of Hole in Moka Funnel
upvoted_answer: Just guessing here, but the hole could keep the water from going up until it reaches a certain temperature. The amount of pressure from the steam varies on the temperature of the water, and if there weren't enough pressure, the water would recycle. However, if the pressure were greater, the velocity of the water would prevent it from dripping out of the hole.
  
  This could explain the bursts, since the pressure would rise and fall depending on the amount of water it pushed out. The more water that escapes, the more room there is left behind for pressure to fill.
  
  Also, you mentioned a weird taste. Could it be metallic? If so, you could try letting the base sit in a strong coffee/water mixture for a couple days. The moka pot needs to be seasoned to prevent this taste, so I would recommend not washing it with soap - just rinse. My grandmother has never washed hers.