Coffee Education · Common Tides Coffee

Great Espresso Starts with Great Water

Espresso is roughly 98% water. That means the water you use is not a small detail. It is the whole drink. Here is how Common Tides approaches water quality and why it matters more than most people realize.

June 2, 2026 Zack Bennett, Founder 5 min read

Most people order a coffee and think about the beans. Maybe the roast. Maybe where it came from. Almost nobody thinks about the water. But if you are serious about what is in the cup, water is not something you can ignore.

Espresso is roughly 98% water. That is not an exaggeration. When you pull a shot, you are forcing hot water through a small amount of finely ground coffee under pressure. The resulting liquid is almost entirely water that has extracted flavor compounds from those grounds. Whatever is in that water comes with it into the cup.

That fact has always been important to me. I started Common Tides because I wanted to serve genuinely great coffee. Treating the water as an afterthought would have undercut everything else I was trying to do.

98%
Of espresso is water
RO
Reverse osmosis filtration used
2
Local Wilmington water sources

Why Wilmington Tap Water Is Not an Option

Wilmington has a reputation when it comes to tap water. People who have lived here for any amount of time know it. The taste, the smell, the general uncertainty around what is actually in the water. I am not going to get into the full history of it, but anyone who has been paying attention to local news over the years knows that Wilmington water has had its issues.

Using that water in a specialty espresso program was never a consideration. It would show up in every single drink. No matter how good the beans are, no matter how dialed in the grind is, bad water produces a worse cup. That is just chemistry.

Water quality is not a talking point at Common Tides. It is a deliberate part of how the trailer operates. If someone is going to spend money on a specialty coffee, they deserve to know that everything going into that drink was chosen with care. That includes the water.

What RO Filtered and Remineralized Actually Means

Reverse osmosis filtration pushes water through a membrane that removes nearly everything. Contaminants, chlorine, heavy metals, and most dissolved solids all get stripped out. The result is extremely clean water, which sounds ideal. But there is a catch.

Completely pure water is actually not good for coffee extraction. Minerals in water play a role in how coffee compounds bind and release during brewing. Water that has had everything removed tends to over-extract, pulling too aggressively from the grounds. The result is a flat, harsh shot that lacks balance and clarity.

The solution is remineralization. After the RO process removes impurities, a controlled amount of minerals is added back in. The water ends up clean, with none of the stuff you do not want, but it has the mineral content it needs to extract coffee the right way. That is the balance we are working with.

"Great espresso starts with great water. If you get that part wrong, it does not matter how good the beans are."

Where We Source Our Water in Wilmington

I source water from two places here in Wilmington. Both use high-quality filtration systems and both are local businesses I feel good about supporting.

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Tidal Creek Co-op

Tidal Creek is Wilmington's local cooperative grocery. They run a FreshPure water system, which is a well-regarded reverse osmosis and filtration setup used in co-ops and natural grocers across the country. I fill up here regularly. It is a good system and it is a local business I have always respected.

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Loveys

Loveys is another local Wilmington source we use. They run a Kinetico water system, which is one of the more reputable names in water treatment. Kinetico systems are non-electric, twin-tank setups known for producing consistently clean water. It is another option that gives me confidence in what is going into the espresso.

Having two reliable local sources means I am not locked into one option. Both produce quality water and both keep the supply chain local, which matters to me the same way sourcing local honey or buying from a local roaster matters.

What This Means in the Cup

Water quality is one of those things that is hard to point to directly when you taste a well-made espresso. You notice it more when it is wrong than when it is right. A shot pulled with poor water tastes off in a way that is hard to describe. It might be bitter when it should be sweet, flat when it should be bright, or just dull overall. The coffee does not perform the way it should.

When the water is right, the espresso can do what it is supposed to do. The sweetness comes through. The finish is clean. The flavors the roaster developed in the beans actually make it into the cup. That is what we are chasing at Common Tides.

I think about this every time I set up the trailer. The beans are important. The grind is important. The temperature and pressure are important. But the water is where it starts, and getting it right is not something I am willing to cut corners on.

Every drink at Common Tides is made with RO filtered, remineralized water sourced locally here in Wilmington. It is one of the less visible parts of what we do, but it is one of the parts I am most deliberate about.

Frequently Asked Questions

What kind of water does Common Tides Coffee use?
Common Tides uses reverse osmosis filtered water that has been remineralized. The water is sourced from two local Wilmington locations: Tidal Creek Co-op, which uses the FreshPure water system, and Loveys, which uses a Kinetico water system.
Why does water quality matter for espresso?
Espresso is made up of roughly 98% water. The mineral content and purity of the water directly affect how coffee extracts and what ends up in your cup. Water that is too hard, too soft, or full of contaminants will produce a noticeably worse espresso no matter how good the beans are.
Why not just use Wilmington tap water?
Wilmington has a well-known reputation for tap water quality. Using tap water in a specialty espresso program would compromise the taste of every drink served. Sourcing high-quality filtered water is a deliberate choice to make sure that what is in the cup is as good as it can be.
What is remineralized water and why is it used for coffee?
Reverse osmosis filtration removes nearly everything from water, including the minerals that help coffee extract properly. Remineralization adds back a precise level of minerals so the water is clean but still has what it needs to pull flavor from the coffee correctly. Pure RO water with no minerals actually over-extracts and produces a flat, harsh shot.

Come Taste the Difference

Common Tides rolls through Wilmington and the Cape Fear coast every week. Check the live schedule and come find us.