Sweet is a flavor you expect from candy and lemonade but not from water. Your drinking water should have a neutral taste, and if it doesn’t, something may be wrong with your water quality.
Let’s take a closer look at some common —and not so common reasons —why water tastes sweet and what you can do about it.
What Makes Tap Water Taste Sweet?
Sweet-tasting water is usually the result of:
#1 Hard Minerals
The most common reason for water tasting sweet is hardness minerals. Primarily calcium and magnesium, they cause a pH imbalance that can give even the cleanest water a sweet taste. Whenever water’s alkalinity, mineral content or pH level rise, a sweet aftertaste usually isn’t far behind.
Fortunately, hard minerals aren’t bad for you. In fact, minerals such as calcium are necessary for the body, and in moderate amounts, they balance a low pH that can make ordinary tap water taste metallic or bitter.
Some of the world’s leading bottled water makers add trace minerals to their products to give them a slightly sweet edge. Humans are biologically wired to love foods that leave a sweet taste in the mouth, so this so-called mineral water tends to be more refreshing.
While all tap water naturally contains minerals from mineral deposits in the soil, well water in rural areas is more likely to contain a high concentration. Known as hard water, it affects more than 65 percent of homes across the United States.
The sweet taste of hard minerals is magnified by limescale — a chalky residue of the same naturally occurring minerals that can build up in your plumbing system if you have untreated hard water. As water passes through pipes, it tends to pick up more minerals, further affecting the way your water tastes.
If you have a salt-free water conditioner to control limescale, but water still has a sweet taste, it’s not unusual. Unlike salt-based softening systems, TAC water conditioners neutralize hard minerals, but they don’t remove them. So, your tap water may still taste sweet.
Lead can give water a sweet taste, but it’s sometimes hard to notice. Water with a low pH is more likely to contain lead, yet it’s also more apt to taste bitter. The flavors often offset each other.
But if you have a pre-1986 home with older pipes or a lead service line, your family is at risk. Lead is a powerful neurotoxin that can cause irreversible health issues in children, so it’s important to ensure your water is lead-free.
Iron is tricky mineral. It’s everywhere in the environment, but it comes in two forms — ferric iron, or rust particles, and ferrous, or dissolved iron. Both can make water taste either metallic or sweet depending on your water chemistry.
Could Health Issues Make Water Taste Sweet?
There are a surprising number of serious health issues that can make water taste sweet.
People with diabetes can’t metabolize carbohydrates because of an insulin deficiency. The resulting high blood sugar levels can cause a sweet taste. In the later stages of the disease, the body consumes fat as fuel in a desperate search for sustenance, leading to a metabolic state called ketosis and an even stronger sugary taste.
Ketogenic diets intentionally induce ketosis to boost fat loss and control some medical conditions, such as seizures. But whether it’s the result of a health problem or intentionally induced for its benefits, it can still make water taste sweet.
Respiratory tract tumors can cause a rise in hormone levels that cause a sweet taste. It’s rare — but talk to your doctor if you have symptoms such as a cough or shortness of breath.
If you’ve ever had a bad cold, you know that anything that affects your sense of smell can cause unusual tastes — more than 80 percent of what we experience as taste is due to smell. If water tastes sweeter when you have the sniffles or post-nasal drip, your nose could be the culprit!
There are some types of normal oral bacteria that taste sweet or salty. Good oral hygiene is the key to resolving these unpleasant flavors. Brushing with baking soda may help neutralize an off- taste.
Could It Just Be My Taste Buds?
Just three genes are responsible for both sweet and savory taste perception. And researchers have recently discovered that variations can make you more or less sensitive to sweet tastes.
Children inherit a copy of this gene from each parent, and how dominant they are determines how intensely you perceive sweetness. It’s baked into your biology.
Scientists have also learned that humans don’t have separate zones on their tongues for specific tastes as once thought. Instead, each taste bud senses all the primary flavors. But there are significant differences in the number and placement of taste buds from person to person, affecting how we discern sweetness.
So, yes, your taste buds could be to blame if your water tastes sweet. If you’re among people with more sensitive palates, a slight difference in your water’s chemistry could drastically affect its flavor.
If you always have a sweet taste in your mouth, or if water from a filtered water cooler still tastes as sweet as your tap water, your own body is likely responsible.
Is Sweet-Tasting Water Safe to Drink?
Tap water with a sweet taste is probably safe to drink unless the problem is lead. Uncommon minerals like zinc and other contaminants can also contribute to sweet aftertastes, so it’s best to diagnose the problem by doing a water test. It’s quick, easy and you can do it at home.
Testing Water with a Sweet Taste
Assuming the cause of the sweet water is minerals or a pH imbalance, we recommend testing for hardness, pH range, iron and because of its dangers, lead.
If you drink city water, you have an advantage. Water treatment authorities test water regularly for the most common contaminants, including minerals. Your annual consumer confidence report, mandated by the Environmental Protection Agency, should show if you have hard water or an unusually high pH.
If your drinking water comes from a well, it’s your responsibility to have it tested regularly. The Centers for Disease Control and Prevention already recommend yearly testing for pH, nitrates and coliform bacteria.
Well water in the US rarely contains naturally occurring lead, but like city dwellers, old farmhouses may also have lead pipes. Unless you can rule out lead in your service lines, well components or plumbing system, you’ll need a lead test kit, too.
A quick way to screen your water is with test strips, but we suggest a more comprehensive approach. Since the best solution for sweet water is usually a water filter, knowing more about your water chemistry is essential when purchasing filtration equipment.
Test kits like SimpleLab’s Tap Score are a window into your water quality – see our recommended water test kits. You can choose from single tests or panels specifically designed to detect the most common city or well water contaminants. Results include guidance on water filtration if you need it. If you’ve never had a water test done before, their helpful experts will walk you through the process step by step.
How to Remove a Sweet Taste from Drinking Water
Installing a water filter is the simple answer to sweet water, but filtration systems are not all created equal. Let’s review the best options.
#1 Carbon Filters
Activated carbon filtration is among the best methods for improving the smell and taste of water. Found in many filters from whole-house systems to filtration pitchers, carbon removes chlorine, lead and a host of chemicals that affect the overall quality of your water.
But a carbon filter doesn’t remove hard minerals or iron, two of the most common causes of sweet water. For that, you need special filters.
#2 Water Softeners
If your water’s alkaline, chances are you need a water softener. Softeners remove hard minerals, existing limescale and low levels of iron and lead. They can improve the taste of water and protect your plumbing system and appliances. But larger quantities of iron over 3 parts per million can ruin softening resin, so it pays to have a water test done so that you know what you’re dealing with.
#3 Chemical or Air Injection Filters
Chemical injection filters use chlorine or potassium permanganate to oxide and filter ferrous iron. But new air injection filters are equally effective without the use of chemicals.
Like water softeners, injection filters are whole-house filtration systems that improve the taste of water and help protect your water-using appliances from rust particles. You can install one before a water softener for maximum filtration.
#4 Reverse Osmosis Filters
Reverse osmosis filters force water through a semi-permeable membrane, capturing clean water in a storage tank while sending contaminants down the drain. They render water virtually pure, removing minerals, lead and more — see our top choices.
But as with water softeners, too much iron can damage a reverse osmosis system. If you have minerals or lead in your water plus iron, you’ll need an iron prefilter.
If you’re turning to bottled water because your tap water tastes sweet — there’s hope. With the right filtration, you can enjoy fresh water again.