These are the questions that sit under every sugar-free recipe on the internet, in the comments and in the search suggestions. Most of them have a mechanical answer rather than a matter-of-taste one, which means you can apply the answer to a recipe nobody has written yet.
Grouped by what you are actually stuck on. If you are at the shop rather than at the counter, the sweetener guide is the better starting point, because most of what follows is downstream of which bag you bought.
Sweeteners
Can I swap a sugar substitute one for one for sugar?
By volume, sometimes. By behavior, almost never. Erythritol is roughly 60 to 80 percent as sweet as sugar depending on what it is dissolved in, allulose sits a little under sugar, and monk fruit and stevia extracts are hundreds of times sweeter, which is why they are sold blended with a bulking agent. The bag will usually tell you the ratio. What the bag will not tell you is that sugar was also holding water, spreading your dough and browning the top, and the replacement does none of that.
Why does my sugar-free bake taste cold, like a mint I did not add?
Erythritol. Dissolving it absorbs heat from whatever it touches, and in your mouth that is your tongue. The full explanation is here, and the practical shape of it is that dry crystalline applications are worst, powdered is stronger than granulated, and anything that dissolved fully into a wet batter is much quieter. You cannot mask it with vanilla or salt, because it is not a flavor. Blending with a high-intensity sweetener so there is less erythritol per bite is the actual fix.
Is allulose a sugar alcohol?
No, and this matters if polyols disagree with you. Allulose is a rare sugar, a different class of molecule entirely, so the digestive complaint people have with maltitol and sorbitol does not carry across. We wrote that up properly because almost nobody states it plainly. It has its own limits at quantity, and tolerance still varies.
Which of them browns?
Allulose browns and caramelizes; erythritol largely does not. If the top of your bake is coming out pale and looking underdone when it is cooked through, that is the sweetener rather than your oven. A small amount of a real sugar, or a swap to allulose, puts the color back.
How do I get rid of the aftertaste?
Start by using less of it. Every one of these gets worse in proportion to how much goes in, and a bake tuned to match the sweetness of the sugar version is usually too sweet by the time it has cooled anyway. After that, blend two sweeteners instead of leaning the whole load on one, since the off-notes of erythritol and stevia sit in different places and cancel each other out more than they stack. Salt helps as well, not by removing anything but by changing what you notice first.
Texture, and why it went wrong
Why did my sugar-free cookies come out dry and cakey?
Sugar is hygroscopic, meaning it grabs and holds water, and that held water is most of what "soft" means in a cookie on day two. Take it out and there is less to hold. The compounding error is that people cut the fat in the same edit, and fat was coating the flour proteins and keeping the crumb tender. Change one variable at a time, and if you have already cut the sugar, leave the butter alone.
Why did my cookies not spread?
Sugar melts in the oven and lets dough flow outward. Erythritol does not do that the same way, so the dough sits where you put it and bakes into a ball. This is not fixable with more baking powder. Press them to the thickness you want before they go in, which is exactly the instruction on our chocolate chip protein cookies for the same reason.
Why is my sugar-free ice cream rock hard, or gritty, or both?
Two separate mechanisms wearing one coat. Sugar lowers the freezing point, so removing it gives you a harder block. Separately, erythritol dissolves poorly in the cold and falls out of solution as the base freezes, recrystallizing into sandy specks. Allulose fixes both, because it depresses the freezing point more effectively than sugar and resists crystallizing. Fat and protein help too, which is why cottage cheese ice cream scoops rather than shatters.
Can I use protein powder in place of flour?
Not one for one. Protein powder absorbs a lot of water and then sets rigid in the heat, so it keeps tightening after the point where flour would have stopped. A bake that is entirely protein powder comes out dry and slightly squeaky. Keep it to a portion of the dry weight, add moisture in a form that stays put such as yogurt or mashed banana, and pull it out of the oven earlier than feels right.
Why did my no-bake never set?
A no-bake sets on fat firming up and on dry material absorbing liquid, not on anything the oven would have done. So it is almost always a ratio problem, and the usual culprit is natural nut butter, which separates in the jar and is a completely different ingredient off the top than from the bottom. Stir the jar, weigh it, and add dry material rather than more time in the fridge. Pressing hard also matters more than people think, which is the first note on our no-bake granola bars.
Labels, and what the words mean
Does sugar-free mean low calorie?
No. In the US, "sugar free" is a claim about sugars only: under 0.5 grams per serving. It says nothing about calories, and there is a rule requiring a sugar-free product that is not also low calorie to say so somewhere on the pack, usually in the smallest type on the box. Since sugar was doing structural work, the thing that replaced it is frequently fat, so a sugar-free version can carry more calories than the ordinary one. The full label breakdown is here.
What is net carbs?
Arithmetic the brand did itself. It is not defined by the FDA, it is not on the nutrition panel, and the usual version subtracts fiber and sugar alcohols from total carbohydrate. That subtraction is more defensible for erythritol than for maltitol, so two products claiming the same net carbs can be genuinely different foods. Total carbohydrate is the regulated line.
Do sugar alcohols upset everyone's stomach?
They are not one ingredient and they do not behave alike. Erythritol is mostly absorbed in the small intestine and leaves through the kidneys, so relatively little reaches the colon. Maltitol and sorbitol largely do reach it and get fermented there, which is where the reputation came from. Tolerance genuinely varies person to person, so a small amount first is the sensible way to find yours. None of this is medical advice, and if you have a gut condition or a blood sugar target, that conversation belongs with your doctor rather than a recipe site.
Can I use honey, maple syrup or coconut sugar and call it sugar-free?
No. All three are sugar, and the total sugars line on a label counts them exactly the same way. They differ in trace minerals and in how fast they hit, and those differences are much smaller than the marketing suggests. Plenty of good recipes use them, including several of ours, and we label those as whole-food rather than sugar-free for this reason.
The one that fixes the most bakes
If you take a single thing from this page: do not remove the sugar and the fat in the same recipe.
Sugar going out already cost you moisture, spread and browning. Fat going out on top of that costs you tenderness, and the two together are the whole explanation for the dry, rubbery, faintly cold result that makes people decide sugar-free baking does not work. It does work. It just needs one change at a time, and a note in the margin about what each one did.
