title_body: Coffee passing through filter during bloom
upvoted_answer: The drip-through of water during the bloom process isn't itself a cause for worry of a 'bad' brew as this process is meant to aid degassing of the beans prior to the main brew pour. The amount of drip-through you're experiencing is completely fine as long as the entire bed of coffee has been wet by the bloom pour.
  
  However, if you reckon there is too much coming through, make sure you're not using too much water relative to your total brew weight in the bloom. If a significant fraction of your water is used during the bloom, and therefore less being used during actual extraction, it will affect the resulting flavour.
  
  I'd argue that as long as the amount of water used for the bloom is less than 1/4 of the total brew water weight and the entire bed is being wet by it, no matter how much filters through, it should not affect the brew significantly.