Taste & ingredients

Monk fruit vs stevia in electrolytes: why some taste bitter

Both are plant sweeteners with no sugar, but the grade a brand picks is the difference between a clean sip and that bitter, liquorice aftertaste people know from sugar-free drinks.

Short answer. Both are sugar-free plant sweeteners. Stevia's cheap common grade, Reb A, is what leaves the bitter, liquorice-like aftertaste in many electrolyte drinks. Monk fruit tastes cleaner but costs more, and so does Reb M, a rarer, cleaner grade from the same stevia plant. Rawstone uses monk fruit plus Reb M.

Rawstone Learn · general education, not medical advice

If you have ever mixed up a sugar-free electrolyte drink and caught a bitter, slightly liquorice taste at the back of the sip, the minerals are not usually the culprit. The sweetener is. Two plant sweeteners show up on almost every sugar-free label, monk fruit and stevia, and how a brand uses them decides whether your drink tastes clean or leaves that lingering edge. Here is what each one actually is, in plain terms.

What stevia actually is

Stevia is a sweetener made from the leaves of a small South American plant, Stevia rebaudiana. The leaves contain a group of naturally sweet compounds called steviol glycosides, and those are what get extracted and purified into the white powder used in food. On an ingredients panel it is listed as steviol glycosides, sometimes with the food-additive number 960. So when a label says "steviol glycosides", that is stevia.

Here is the part most people never hear: stevia is not one single thing. The leaf contains several of these sweet compounds, and they do not all taste the same. Some are clean. Some are bitter. Which ones end up in your drink comes down to grade and cost.

What monk fruit actually is

Monk fruit is a sweetener made from a small green gourd, a bit like a round melon, that grows in southern China. Its sweet compounds are called mogrosides, and the main one used in food is mogroside V. Monk fruit is intensely sweet, many times sweeter than sugar, so only a tiny amount is needed. People tend to describe its taste as fruitier and rounder than stevia, with less of a bitter edge. The trade-off is that it is more expensive to produce than stevia, so it is less common in lower-cost drinks.

The real split: Reb A versus Reb M

This is where the taste difference lives, and it is worth slowing down for. Remember that stevia is a family of sweet compounds, not one. Two of them matter here.

Reb A, short for Rebaudioside A, is the common, cheap grade of stevia. It is present in the leaf in decent amounts, so it is easy and inexpensive to extract in bulk. It is also the one that carries the bitter, liquorice-like aftertaste stevia is famous for. If a sugar-free drink has ever tasted off to you at the back end of the sip, there is a good chance you were tasting Reb A.

Reb M, short for Rebaudioside M, comes from the very same stevia plant, but it is a different compound. It tastes much cleaner and closer to sugar, without that bitter finish. The catch is that the leaf only holds a tiny amount of it naturally, so it is far harder and more expensive to produce. That extra cost is the main reason Reb A is the more common grade on shelves.

The key point: Reb A and Reb M both come from the stevia plant. Reb A is the cheap grade that tastes bitter. Reb M is the rare, clean-tasting grade that costs more. Same plant, very different sip.

Why "no stevia" is the wrong thing to look for

Because Reb A gets a bad name, "no stevia" sometimes appears on the front of a pack. It sounds reassuring, but it can point you in the wrong direction. Reb M is a stevia compound too, so a drink using the good, clean grade would technically fail a "no stevia" test, even though it may taste better than a product that avoids stevia altogether. The useful question is not whether a drink contains stevia. It is which grade, and how heavily it is dosed. A light hand with a clean grade beats a heavy hand with a cheap one every time.

What Rawstone uses, and why

Rawstone is a sugar-free electrolyte hydration powder, sweetened with monk fruit and Reb M, both kept dialled down. We chose the clean Reb M grade so the drink tastes smooth and closer to sugar, without the bitter, liquorice finish that some sugar-free drinks leave behind. There is no sugar, no maltodextrin, and no artificial sweetener such as sucralose or aspartame.

The reason this matters more in an electrolyte drink than in, say, a soft drink is the minerals. A serve of Rawstone carries 1000mg of sodium, 250mg of potassium and 75mg of magnesium. Salt and mineral citrates bring their own sharp, sometimes metallic edge, so the sweetener has to work cleanly alongside them rather than adding a second off-note on top. A clean grade like Reb M keeps the finish smooth, which is what makes a strong mineral drink easy to actually finish. If you want the wider picture on why the sodium dose is set where it is, see the science of salt and hydration, and for the safety question, is 1000mg of sodium too much.

None of this is a health claim about sweeteners. It is simply about taste, and about being straight with you on what is in the tub and why.

Rawstone is launching on Amazon Australia, 1 Nov 2026

Sugar-free, sweetened with monk fruit and Reb M, and every batch will be independently lab-tested. Join the list for a launch-day discount code.

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Is monk fruit or stevia better in an electrolyte drink?

Neither is simply better. They are both plant sweeteners with no sugar. Monk fruit tends to taste fruitier and cleaner but costs more. Stevia is cheaper, and its common grade, Reb A, is the one that leaves the bitter, liquorice-like aftertaste people notice in a lot of electrolyte drinks. A rarer stevia grade called Reb M tastes clean, which is why some brands blend monk fruit with Reb M.

What is the difference between Reb A and Reb M?

Reb A and Reb M are both sweet compounds from the same stevia plant. Reb A is common and cheap to extract in bulk, and it carries the bitter, liquorice aftertaste stevia is known for. Reb M is present in the leaf in tiny amounts, tastes much cleaner and closer to sugar, and costs more to make. That price gap is the main reason most brands reach for Reb A.

Why does my electrolyte drink taste bitter?

A common cause is the sweetener. Many sugar-free electrolyte drinks use Reb A, the cheap grade of stevia, which leaves a bitter, liquorice-like note at the back of the sip. A heavy dose of any sweetener can also start to taste off, and strong mineral salts add their own edge. Choosing a cleaner grade like Reb M and dialling the sweetness down both help.

Does Rawstone contain stevia?

Yes, in the form of Reb M, the cleaner-tasting grade, which comes from the stevia plant and appears on the label as steviol glycosides. We pair it with monk fruit and keep both dialled down. We do not use the cheap Reb A grade that causes the bitter aftertaste, and there are no artificial sweeteners such as sucralose or aspartame.

By Tom Bolger, Rawstone co-founder. Rawstone is built by two founders with around thirty years of food and beverage manufacturing between them, and both of us train in the gym. Tom helped formulate Rawstone and will send every production batch to an independent lab, with the test certificate posted here publicly from our very first batch.

This article is general education about ingredients and taste, not medical or dietary advice. Rawstone is a food supplement, not a medicine, and is not intended to diagnose, treat, cure or prevent any disease. If you have a condition that means you need to manage what you consume, talk to your doctor before using any electrolyte supplement.