I am getting a concave look to my coffee bed when I brew a 15:250 size serving in my V60. I do not get this when I am brewing 30:500, the bed is completely flat.
I am using the same grind size and following James Hoffmann’s ultimate V60 technique in both brew sizes
I have attached a picture of concave coffee bed.
Too aggressive of a pour during the brew? or too aggressive swirling during the draw down?