Water isn't just a carrier for your beans; it's the star player.

Filter coffee is over 98% water, espresso around 87-93%, so even killer beans, a fancy grinder, and perfect technique can flop if your water's off. Bad water mutes bright, fruity notes, and makes rich flavors taste flat, chalky, metallic, or overly bitter. But the good news: tweaking it is totally doable, and once you do, you'll taste the difference immediately. It's like unlocking a hidden layer of your favorite roast—motivating, right? Let's break it down step by step, with real, actionable steps to get you started.

Why does the same coffee at home taste different than at a coffee shop?

Have you ever gone to a great coffee shop and had a great cup of coffee, splurged on a bag of those same beans, but your brews at home just don’t taste as good? Chances are it’s your water. Water trumps everything else. Poor water neutralizes the vibrancy we love, prevents flavor clarity, adds off-flavors, and even wrecks your gear with scale buildup. On the flip side, optimized water enhances sweetness, complexity, and body, making even average coffee shine to its fullest potential. If you're tired of inconsistent brews, this is your lowest-effort upgrade, and it can be easy.

Tangible Ways to Improve Your Coffee at Home

1. Bottled Water: This is arguably the simplest way to get great water. The trick is buying the right water. It’s not simple to provide a recommendation either. Every gallon of water on the shelf has a different chemistry and mineralization level. I suggest gallons of Great Value spring water for filter or immersion-style coffees as an affordable and widely available option. It’s not the only option, but generally it meets a fairly ideal water chemistry for coffee. It works pretty well for espresso too, but espresso lovers might want to experiment with Zephyrhills spring water or Eternal Naturally Alkaline Water. They have a bit higher alkalinity, but relatively low hardness, which helps tame acidity in espresso and can give you a bit more cushion if your espresso isn’t perfectly dialed in, while giving you enough minerals for a rich body without taxing your machine too much with scale buildup.

2. Filters: Using common home water filters will have some limitations, though they are absolutely better than using tap water.

   • Activated carbon filters: These filters are the most common, and most people have them. It’s the filter in your fridge, or if you have a Brita pitcher.

     • Pros:

       • These pitchers are cheap and most people already have them.

       • They help remove off flavors and contaminants which makes the water healthier and removes off flavors that hurt your coffee flavor.

     • Cons:

       • They don’t alter water chemistry or mineral levels, so you will still lack some clarity and balance.

       • It’s definitely better than tap, but it’s far from optimized water.

   • Reverse-osmosis (RO) system: Many Florida homes have an RO system under their kitchen sink. RO systems remove off flavors, contaminants, and 90-99% of minerals. They’re pretty easy to install and not overly expensive if you don’t have one already.

     • Pros:

       • With a properly functioning system, you will have good water. You’ll just be able to use the water straight out of the spout without any issues and have delicious coffee.

       • It will also drastically decrease scale, which decreases the maintenance effort on many brewing machines.

     • Cons:

       • If you have a system that removes 99% and doesn’t have a remineralizing function, you might actually be removing too many minerals and have water that’s essentially demineralized, which requires remineralization otherwise it will produce harsh acidic coffee regardless of adjustments you make to your grind and brewing technique.

       • If you’ve had the system for quite some time and haven’t maintained it by regularly replacing the filters, it’s possible there are off flavors from bacteria growing in the filters or even have a failed system, where the water isn’t any better than tap water. (If you have an RO system, keep up with filter replacement as recommended by the manufacturer)

   • “Zero” filters: These are usually pitcher-style filters, where you pour water in the filter tray and they trickle through the filter into the basin.

     • Pros:

       • These pitchers remove all contaminants and minerals. Essentially, it demineralizes your water. This might be a nice solution for you if you want to remineralize your water.

       • It may be more affordable than purchasing gallons of distilled water

       • It gives you the flexibility to create demineralized water on demand.

     • Cons:

       • If you’re looking for the simplest solution, this isn’t for you. As we’ve already discussed, we don’t want zero mineral water for coffee. Adding minerals can be done without much fuss, but it is an extra step and extra expense.

       • In my experience, these filters have almost no time between the time they stop functioning properly and when they go rancid. So if you go this route, you need to be VERY on top of when to replace your filter.

For those who want to dive deep:

1. Additives for Customization: Buy distilled or reverse osmosis water (or use your reverse osmosis system at home), then add dry salts or remineralization drops. You can buy salts individually, premixed to profiles from Third Wave Water, or drops from Lotus. This lets you dial in flavors. Lower alkalinity boosts acidity, raising it tames the acidity. Increasing hardness impacts the sensory experience more than flavor, but can increase the sense of body and perceived sweetness. A little bit goes a long way for both, and in excess both can quickly turn a delicious cup of coffee flat.

2. Zero-Mineral Experiments: Brew a batch of coffee with pure distilled water and divide evenly across 4 cups. Leave one mug unaltered, then progressively add drops of each of the remineralization drops, increasing by 1-2 drops as you go (depending on the volume of liquid). So your first cup should have no drops, your last cup should have 3-6 drops. Then try them in order. You will gain the experience of how alkalinity and hardness change how your coffee tastes. You can also experiment by adjusting only hardness or alkalinity levels. In that case, say you want to experiment with alkalinity. Do the same brew with distilled water, dividing equally into 4 cups. Add a couple drops of magnesium or calcium in every cup, so they are all equal. Then progressively increase the amount of sodium bicarbonate drops by 1-2 drops in each cup like explained previously, and taste how alkalinity changes the flavor profile of your coffee. Then do the inverse with keeping alkalinity the same, and only adjusting hardness.

3. When to mineralize: Studies have shown there is no benefit to adding minerals prior to brewing. It doesn’t increase extraction or noticeably change the flavors on the end cup. Depending on your remineralizing or brewing method, it may be easier to remineralize before or after brewing. A couple examples: If you’re using salts, you probably want to mix in large volumes. It doesn’t take much, so usually you want to remineralize about a gallon at a time and then just brew with your water. I remineralize my water for espresso before dumping it into my espresso machine water tank. I use drops for most other brew methods. I’ve found it very easy to add after the brew, before I swirl or stir.

4. Water chemistry: We don’t need to dive too far into the weeds here, but in case you want specific details and recipes I’ll offer 2 as a starting point.

   • Light and bright: 60 GH, 30 KH

     • Like fruit-bomb light roasts? Do you like modern ultra-light roasts that have a floral and tea-like quality? This one is for you.

   • Specialty balanced: 90 GH, 45 KH

     • Like a touch more body, but don’t want to dull out the great natural flavors? This will give you a well-rounded cup that might pull in a few more rich notes, but keeps enough acidity to still let the fruits shine.

   • Espresso: 90 GH, 200 KH

     • You should try espresso at a bunch of different KH ranges, but I find this one to be a great all-rounder. It’s perfect if you want rich and sweet espresso. If you’re brewing espresso with specialty coffee that isn’t darkly roasted, this helps tame the sourness that often accompanies shots that aren’t perfectly dialed in. And, while I’d love to tell you that we all pull a couple shots to dial in at home every morning, that isn’t how most people operate and having some built-in forgiveness from your water chemistry is very welcome in my book.