February 12, 2021

Brewing: When the Bean and Water Unite

By Scott Thomas
Pouring hot water into a chemex pour-over coffee makeer

There are many factors to brew a good cup of coffee and many ways to manipulate the interaction between the bean and water.

The most important factor is the water; however, we also have extraction, brew ratio and dose, grind size and contact time, temperature, and pour.  Is your head spinning?  Never knew so much went into a good cup of coffee?

Water:  Coffee is 98% water.  Not all water is created equal.  If you start with poor water, you end up with poor coffee.  If you do not have good tap water, use a carbon filter.  Be careful not to filter out all the minerals because minerals help pull out the coffee flavor and texture.  The best water for brewing coffee is either bottled spring water or reverse osmosis (RO) water. 

Extraction:  Extraction is what turns water into coffee.  The coffee compounds in the grounds (insoluble oils, soluble gases, insoluble solids, soluble solids) come alive when united with water.  In other words, the water pulls the flavor and texture compounds from the coffee grounds.  The goal of extraction is to create a balance between the dissolved compounds so that the taste is not too bitter, sweet, or acidic.

Brew Ratio and Dose:  This refers to how much coffee and water to unite.  Many of you probably use a tablespoon to measure your coffee grounds.  I will let you in on a secret … not every tablespoon or measuring cup produces the same mass.  To take your brewing to the next-level I recommend measuring your water and coffee grounds via a kitchen scale. 

Grind Size and Contact Time:  The finer the grind the less contact time (the time that the coffee grounds and water are united) is needed and versely the coarser the grind the more contact time is needed.  Just as not every tablespoon produces the same mass, not all grinders produce the same grind size.  It will be easier to compare grind size with other kitchen compounds such as salt and sugar (see our Know Your Grind Size cheat sheet).  Different grind sizes work better with different brewing devices which is also covered in our Know Your Grind Size cheat sheet.

Temperature:  Water temperature influences how the coffee compounds are dissolved.  The ideal temperature is between 195 to 205 F.  Boiling water can produce bitter tasting coffee.  With elevation the boiling point of water decreases so if you live in a higher elevation, you may need to experiment with your ideal water temperature.

Pour:  If you use a pour-over brewing method, the way you pour the water can affect your coffee taste.  You need to pour your water in a slow and controlled method.  When using this brewing method, you do not want to allow your grounds to soak in a pool of water nor do you want your grounds to leave the filter, you want to evenly distribute the water by pouring at a consistent pace.

This was just a brief review of the factors involved to brew a delicious cup of coffee.  Some of the factors have a scientific basis and others are based on trial and error.  So, experiment with these factors and have fun brewing your delicious coffee.

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