With all brewing methods, our goal is to discover simple, repeatable techniques that produce consistent good results.  Our Aeropress technique combines immersion brewing, percolation (drip) brewing, and pressure.  Before discussing the brewing variables such as grind size, water temperature, and brew ratio, we want to just explain the technique we use to show just how simple it is.  We hope that it provides you with a framework to use, modify as needed, and make your own.

Step 1: The technique

• Place a filter on the Aeropress and screw the cap onto the base of the Aeropress.  Our preference is to use paper filters rather than metal filters as it produces a cleaner cup with less coffee fines in the brewed coffee.  
• Place the Aeropress (filter down) on the container you want to brew into whether that is a cup or a decanter.  The main thing to consider is whether the container can withstand the force of you pressing the plunger down on the Aeropress.  If you have to use much force, your grind size is too fine.
• Carefully pour the desired amount of ground coffee into the Aeropress. We find using the supplied funnel makes this much cleaner and efficient.  
• Gradually pour the desired amount of water into the Aeropress in one pour if possible.  With this approach we find that 300 grams of water is the maximum amount of water we can pour at one time before reaching the top of the chamber.  If you need to allow some of the water to drain before adding the remainder of the water, this is no big deal.  The main constraint is getting the entire amount of brew water into the Aeropress before the stage where you press the Aeropress.    
• Do not put the plunger on the Aeorpress.  At this stage, we use the Aeropress as a zero bypass dripper.  We allow water to slowly drain though the bed of coffee until we have reached our target steep time.  
• Once we have reached our target steep time, we place the plunger on the Aeropress and slowly press the plunger all the way down until you hear a hissing sound.  If you are using a digital scale, please make sure to remove the Aeropress and brewing vessel from the scale before pressing to avoid damaging the load cell on the scale.
• We use steep time as the primary means to adjust the flavor we extract from the coffee.  For lighter coffees, if we want to extract fruity, floral, expressive flavor notes, we use a steep time of one minute.  Less than that and we find that it often results in coffees that our out of balance.  If the coffee tastes too acidic, too expressive, or just out of balance and we want to tone some of those flavors down, we incrementally lengthen the steep time up to two minutes.  For darker coffees, the primary concern is over extraction resulting in bitterness as darker roasted coffees are more water soluble and easier to extract.  To avoid over extraction, we start with a shorter steep time of thirty seconds.  If the coffee tastes weak or under extracted, we recommend incrementally lengthening the steep time to increase the extraction until you find the right balance of flavors in the cup.  Unless the coffee is really out of balance, we recommend adjusting the steep time in increments of fifteen seconds.    

step 2: water temperature

If you have a temperature controlled kettle, we recommend starting with a water temperature of 200F.  We have found this to be the sweet spot for almost all roast levels IF you follow the steep time recommendations above.  That being said, if you follow the above recommendations and find you need to increase the extraction raise the water temperature incrementally.  If you find you need to decrease the extraction, lower the water temperature incrementally.  Unless the coffee is really out of balance, we recommend adjusting the brew temperature in increments of 3F.  It sounds like a small change to go from 200F up to 203F or down to 197F, but it can make a significant difference for many coffees.        

STEP 3: GRIND SIZE

We use the same grind size for an Aeroporess that we do with pour over and drip coffee, which we categorize as medium-fine. This is a bit courser than what many online Aeropress recipes recommend, but for us it strikes the right balance of sweetness, acidity, and body without the astringency or bitterness that can manifest itself as a result of grinding too fine.     

Step 4: Brew Ratio

Our default recommendation is to start with a 1:15 ratio such as 13 grams of coffee to 200 grams of water or 20 grams of coffee to 300 grams of water depending on how much coffee you want to brew.  This is our preferred ratio for immersion brewing and filter coffee.

STEP 5: EXPERIMENT 

This technique consistently works really well for us with both lighter and darker coffees, but at the end of the day coffee is preferential and personal.  Experiment with this and other techniques to find an Aeropress technique (or a modified version) that consistently works for you to extract flavors you enjoy from the coffees you brew.  If you have questions or feedback, we would love to hear from you.  You can reach out to us by email at info@kethcoffee.com or on Facebook page.