Specifying brew parameters
Each bag of barismo drip coffee will specify a dose. The dose for a "one-cup" (150-210 ml output) brewer will be 15-20 grams of coffee. A "two-cup" (300-360ml output) brew will be 25-30 grams.
Additionally, each bag of drip coffee will specify a temperature between 88°C and 92°C. The water in your kettle should be as close as possible to the specification at the beginning of the pre-infusion.
Water is specified by volume, but can be most easily measured by weight while pouring. 1 milliliter of water weighs 1 gram.
Each brew method specifies a particular timing sequence, to ensure proper extraction. If the grind is correct, the brew will finish just as the timer expires. Grind finer if the coffee drains too quickly, and coarser if t drains too slowly. A paper filter will require a slightly finer grind than a cloth filter.
Rinse the filter with boiling water before and after each use. Between uses, store in damp in a sealed plastic bag in the refrigerator. Do not allow the filter to dry or it will become distorted and acquire an unpleasant "clothy" taste. When the filter starts to turn dark or restrict flow it can be cleaned with a coffee detergent like JoeGlo™. Never use bleach or laundry detergents, however. Replace the filter when detergent no longer cleans it effectively.
All methods start by preheating/prewetting the filter in the brewer. With the filter empty, pour several ounces of hot (at least 85°C) water over the entire surface. In addition to preheating the brewer, rinsing serves to remove any "papery" or "clothy" flavors the filter might otherwise impart on the brew.
Pour the specified does into the filter. Dig out a circular divet in the center about 1cm deep and 2cm in diameter. This circular indent will help facilitate proper preinfusion by ensuring all of the coffee bed gets saturated evenly throughout the initial pour.
With a kettle of water at the specified temperature, pour about 30ml. Start in the center and spiral outward; make sure the entire surface is wet but avoid pouring directly against the filter. Only enough water should be poured to sufficiently saturate the coffee bed. No actual extraction should be taking place at this stage of the brew. When you’ve finished pouring, immediately start the timer.
Start the timer immediately after the pre-infusion pour. Fresh coffee will "bloom", forming a crusty dome. The dome should stop growing but not quite look dry at the end of the pre-infusion time.
Start pouring into the center of the dome, then move in concentric circles outward and back in. Never pour all the way to the outer edge; leave a few millimeters of border. See the brew guide for your particular brewer for the time and volume of the pour.
A "one-cup" brewer will use one continuous pour; a "two-cup" will have a short pause halfway through. See the brew guide for your brewer for exact timing. An ideal pour will leave a symmetric cone of wet grounds.