Sugar makes life sweet, but the keto diet requires its followers to give up regular sugar as well as all of its comrades like honey and maple syrup. If you've looked into keto recipes, you've probably seen a lot of different sweetener suggestions, as well as the term "sugar alcohol" as a somewhat ubiquitous descriptor of many keto sugar substitutes. There is an ever-growing product pool of natural sweeteners that are free (or nearly free) of sugar and are appropriate for the keto diet. We'll discuss the most common and widely available ones as well as how to use them most effectively in your sugar-free cooking and baking.
There are many artificial sweeteners in existence that are technically keto, too. Since they're not natural food products, we will stick to items that are naturally derived from food and have been shown not to cause the potential health problems that some artificial sweeteners can lead to. Because we want to focus on naturally noncaloric sweeteners that are unlikely to cause digestive issues, we are not including maltitol or sorbitol in this list, as their digestive impact can be tumultuous.
Sugar Alcohols: A Quick Tutorial
Before delving into each keto sweetener and what it's best used for, let's first make sure you understand the term that many of them involve: sugar alcohol. Sugar is a carbohydrate that has a sweet taste. When you eat it, your body uses it to produce energy. Sugar alcohols also taste sweet, but their structure is not a straight carbohydrate because our bodies do not process them like carbs. Sugar alcohols have a structure that resembles both sugar and alcohol (though they contain no ethanol and are safe for people who avoid alcohol), and your body doesn't break down the carbohydrate part of that into energy. They contain many fewer calories than sugar, and the carbs in them are mostly not in the "net" carb count because, like fiber, they pass through you without being properly digested.
Sugar alcohols occur naturally in many foods such as melons, strawberries, and avocados, and are obtained through a processing method that separates them into their own product. Sugar alcohols are anywhere from 25 to 100 percent as sweet as sugar, and some of them have a cooling effect in the mouth. Because they aren't absorbed like sugar, they generally don't impact blood sugar. To varying levels, sugar alcohols may impact digestion—we'll review the potential for that as we talk about each keto sweetener.
The first of two common natural keto sweeteners that aren't sugar alcohol, stevia is derived from the stevia rebaudiana plant. It's been used indigenously in South America as a sweetener (as well as a medicine) for centuries, if not millennia. Stevia naturally contains no calories, and it doesn't have any impact on blood sugar. The leaves of the stevia rebaudiana plant are incredibly sweet: They're 200 to 300 times as sweet as sugar. They also contain innate bitterness. Because of this, the stevia rebaudiana plant is processed using only the glycosides of the plant, resulting in a powdered or liquid sweetener that is incredibly concentrated.
Because it is so sweet, stevia is never used cup-for-cup in baking. Instead, it is used in conjunction with sugar alcohol-based sweeteners to help bump up their flavor. You'll notice that stevia is usually an ingredient in any cup-for-cup noncaloric sweetener combination. If you want to use stevia alone, it's ideal by the pinch or the drop in beverages, smoothies, salad dressings, or other culinary preparations. It isn't advisable to use stevia alone in a baking recipe because the volume lost from sugar could offset the recipe too much.
In terms of liquid or powder, many people find the liquid to have less bitterness than the powder. Stevia liquid drops are available in a wide variety of flavors, which can help mask the bitterness further.
Known as lo han guo in its native China and Thailand, monk fruit sweetener comes from the juice of a small green melon. The juice of the monk fruit naturally does not contain calories and is 150 to 200 times sweeter than sugar. Because the juice also has sulfuric qualities, it's processed to keep only the sweet aspect. Similar to stevia, monk fruit cannot be used alone in baking if sold as its own product but, unlike stevia, monk fruit is typically sold packaged with a sugar alcohol sweetener. While you should check labels to verify this, it's typical for the package to say "use like sugar." Alone, monk fruit is available in droppers like stevia to use a tiny amount at a time.
Monk fruit cup-for-cup sweeteners are generally just called monk fruit even though they have sugar alcohols added. A popular brand of monk fruit uses the name Lakanto, which has led people to think it's a different product than monk fruit; it's actually the same. Lakanto bulks up the monk fruit with erythritol, a sugar alcohol, and the name is for branding's sake. Monk fruit is available in granular form like sugar or powdered to be used instead of confectioners' sugar.
Derived from birchwood, xylitol has been used in processed items like toothpaste and chewing gums for decades. That's because, in addition to being naturally sweet, it helps prevent tooth decay. Xylitol has a pronounced cooling effect in the mouth that many people find to be stronger than that of any other sugar alcohol sweeteners, especially as baked goods sit; the cooling effect can increase after items cool from baking. It's about 90 percent as sweet as sugar and so is usually sold alone. It doesn't caramelize and may crystallize when heated. Additionally, xylitol is toxic to dogs, so anything made with it must be kept well out of reach of pets. Though it was the first widely available sugar alcohol and was used in many food products accordingly, xylitol is less useful than erythritol and allulose, and as such is less common in cooking and baking these days (though still widely used in processed items).
A sugar alcohol made from corn, erythritol is about 70 percent as sweet as sugar and contains only a small fraction of a calorie per gram. While it has some ability to caramelize, it can be tricky to work with because heating can cause it to crystallize. Because of this, a specific erythritol-based product has taken over the sugar-free market by adding ingredients that make it more cooking and baking friendly. Swerve is a product that contains erythritol, natural flavors, and a particular type of prebiotic that prevents crystallization, making it much easier to work with. Swerve is available in a granular form similar to table sugar as well as confectioners' and brown sugar. Regardless of brand, erythritol has a cooling effect in the mouth. This makes it best used with strong flavors so that the effect is less noticeable.
Because erythritol is a sugar alcohol and is not digested, it can cause digestive upset. This is typically fairly minimal, and Swerve claims that their addition of prebiotics mitigates this potential. It's worth noting that erythritol can have strange effects on coloring: When mixed with sunflower butter, baked goods will turn dark green within a day.
A naturally occurring sugar alcohol found in foods such as jackfruit and raisins and referred to as a "rare sugar," allulose has changed the sugar-free products industry with both powder and liquid sweeteners that hold up better to both freezing and baking than their predecessors. If you have purchased reduced sugar or sugar-free items in the last year or two, chances are allulose was an ingredient in them; it has gained popularity quickly because of how similar its taste is to sugar.
It doesn't have the cooling effect that erythritol and xylitol have, and it caramelizes well. It also doesn't crystallize when heated, and while it has a sweetness at about 70 percent of sugar, it contains 90 percent fewer calories than sugar. The carbohydrates in allulose are not digested, so it doesn't affect blood sugar. Additionally, the intestinal distress potential of sugar alcohols is lower with allulose, and it is considered well tolerated on that front provided it's consumed in moderation.
Allulose is sold as a powder in granular form like sugar and as a syrup. The syrup is an excellent replacement in recipes calling for honey or maple syrup, but because it browns more quickly than sugar, care should be taken for it to not over darken or burn. The powder is not sold in cup-for-cup format yet, so you can either replace each cup of sugar in a recipe with 1 1/3 cups of allulose or use 1 cup allulose bumped up with powdered or liquid stevia. The quantity of stevia is heavily dependent on the brand, as they can differ significantly, but an average amount would be 1/2 teaspoon.
In addition to these individual sweeteners, there are numerous blended sweeteners available for keto baking. Most have a combination of the above ingredients, though some may contain less beneficial foods too, such as dextrose. If you'd like to make your own blend, provided you use all powdered ingredients, it will store well. With these options, keto baking can be sweet, natural, and easy on your stomach.