How to make an excellent cup of coffee

tom walsh of cambria coffee roasting company

Welcome back!  I thought I’d start a series of posts that describe how to make good coffee at home.  I’ve had a lot of questions from customers recently about why their coffee doesn’t taste the way it does here at the shop.  And it gradually dawned on me that the very basics of making coffee are sometimes mis-understood or are mis-applied at home.

So here we go with the first of what I think will be 4 posts on making coffee.

Making a great cup of coffee at home

As most of you that know me can verify; I love my coffee.  I make coffee at home just about every day of the year, and I’ve come to notice how hard it can be to consistently make a great cup.  Which got me to wonder how many of you face the same problem. And although brewing an excellent cup can be quite simple, there are some very important pieces of the puzzle that need to be in place before one can aspire to coffee excellence.  With these initial blogs, I am going to explain the issues around brewing great coffee, and the steps you need to take to be able to consistently create that perfect cup.

I will break down the process of brewing great coffee into 4 individual segments:

  • Water
  • Coffee and Coffee to Water Ratio
  • Coffee Grind and Grinders


  • Brew Methods


Wow, as I prepared for writing these essays I did quite a bit of research on water and what constitutes good water for coffee.  I think I could have saved myself some pain and just hit myself on the head with a hammer for a couple of hours instead.  To say that good water is critical for a great cup of coffee is an understatement.  To begin to describe what good water is and how you get it is almost impossible to do and still have you read this blog.  However, I will make this issue simple for you.  Just bear with me a moment.

Before I tell you how to obtain good water, let me first explain a few things about coffee and water.

Coffee is approximately 98.75% water.  Just water.  Yes, that 12 oz. cup of coffee you drink is 11.85 ounces of water.  Only about 1.25% is actual coffee.  So you can see why having fresh, good tasting water is so important in making a good cup.

How can you tell what good water is?  This is where things get to be a bit tricky.

Good water needs to have some mineral content to help extract the appropriate contents from the coffee.  Too much mineral content will begin to flavor the water, will do harm to heating components in your brewing equipment and not allow the water to extract all it needs from the coffee.  Too little mineral content in the water (as in distilled water) and it will begin to taste flat and actually over extract the coffee.  Measuring the waters Total Dissolved Solids (TDS) is one way to begin to understand how much “stuff” is in your water.  And, yes, you can do this at home with a relatively cheap piece of equipment (~$25) called a TDS meter available at and other places, but probably necessary for only the geeks out there.

Quality water for coffee should have a TDS reading of 75-150 parts per million (ppm) or mg/L (essentially ppm and mg/L are equivalent).

Usually, the water that the city or county provides to our homes isn’t water that will help our coffee.  It is either too hard or too soft (meaning too much mineral content) or treated with chemicals that can affect flavor (chlorine is really noticeable).

Well, what about home water treatment?

Water Softening:  Some may think that since they use a water softening system at home their water is good for coffee.  Unfortunately that is not true.  Many home water systems don’t meet the criteria for making a really good cup of coffee.  Water softeners typically use ion exchange mechanisms, meaning they trade one or more minerals for others, and do not reduce the total amount of minerals in the water. Usually they remove calcium carbonate and magnesium carbonate (major contributors to hard water) and replace them with sodium or potassium ions.  The sodium can be quite noticeable in taste and is definitely a problem in making quality-brewed coffee.

Reverse Osmosis: RO water is water that has been thoroughly filtered to remove most of the solid “stuff” in water.  Typically, RO systems are greater than 90% efficient in removing mineral content.  An example: water that is very hard, 350 or greater TDS could be refined to water that had at TDS of 35 or less.  Although this is probably much better in quality than softened water, it runs the risk of being too clean and tasting flat and over extracting coffee.

So now that we have established that good water quality can be described as having a TDS of approximately 75-150 ppm and no noticeable minerals, chemicals, or gasses that will contribute “off” flavors, what is one to do?  The simple answer is to purchase good bottled water.  With this one change I believe most of you will detect a noticeable and positive difference in the quality of coffee you make at home.  Try it.  Pour a glass of water that you have from home and do the same with some bottled water that you purchased.  Take a sip of each.  Try it on your family members.  Clean, pure water with the correct mineral content tastes great.  And remember…it’s 98+% of your coffee.

Not all bottled waters are equal, so which ones are worth purchasing?  Well personally, I use Crystal Geyser Alpine Spring Water.  It is readily available in my area and not expensive.  It usually has a TDS reading around 125, so it has just about the correct amount of mineral content and no chlorine or other chemicals that affect taste.

Here is a good link that provides an analysis of most of the globally produced bottled water along with TDS levels and other interesting facts:

Yes, water quality is really important!


Well, you’ve made it through Part 1!  My next post will talk about how to get the correct amount of coffee ready to grind for the amount of liquid coffee you want to drink.  Sounds simple, huh?  Stay tuned….