One of the most common sugar alcohols. Xylitol has a sweetness roughly the same as table sugar (I’d personally put it at around 90%), and also has a cooling effect on the tongue (although it is less pronounced than the cooling effect of erythritol).
As with some other sugar alcohols, I’ve found that xylitol can present a challenge when trying to incorporate it into bakes. You might find that cookies baked with xylitol taste great shortly after baking, while the cookies are still warm and soft, but an hour later that same cookie can taste pretty weird, as the cooling effect of xylitol has been reintroduced (see below for details).
Personally I’ve found that xylitol has a more pronounced gastrointestinal effect (basically, it makes me more gassy) than erythritol. Again, this comes down to how your body will react – some people naturally have a greater resistance to this than others, but I would recommend using no more than 50g of xylitol in any recipe.
Like other sugar alcohols, xylitol is water-soluble, but tends to dissolve far quicker at a lower heat than table sugar. The flip side of this is that the molecules are very attracted to each other, so they tend to bind together and recrystalise very quickly when cooling. This crystallisation leads to the reintroduction of the cooling effect, which is due the heat of solution (or enthalpy of solution), which is endothermic in most sugar alcohols (with the exception of glycerin). This means that it requires more energy to convert xylitol to a solution, and so a side effect of that process is the absorption of heat energy. For comparison, table sugar has a very mild negative heat of solution of about -4 calories per gram, whereas xylitol uses around -36 calories per gram.
Xylitol is not a reducing sugar and will not react with amino acids in the same way, and so will not melt or brown in a Maillard reaction.
Xylitol is naturally produced as white crystals almost identical to table sugar, and has a very similar mouthfeel, with the exception of the cooling aftertaste. This cooling aftertaste can be negated by heating xylitol into a syrup or dissolving in a liquid, but will naturally want to recrystallise very quickly, which will reintroduce the effect. It is the sweetest of all sugar alcohols, with roughly 90% the sweetness of table sugar.
|Xylitol (birch sugar)||Sugar|
|Sweetness Where table sugar has a sweetness of 100%||90%||100%|
|Glycemic Index Where glucose has a G.I. of 100||12||65|
|Calories per teaspoon Where a teaspoon is, on average, 4g||10||16|
Xylitol can cause mild gastric distress (bloating & gas) and laxative effects when consumed in large quantities. Recommendations are to consume no more than 50g for adults and 25g for children.
On the plus side, xylitol has no harmful effects on your teeth, and actually feeds good bacteria in your mouth which can help defend against tooth decay, as well as actively inhibiting the growth of harmful bacteria.
Xylitol is toxic to dogs and is often fatal, as it lowers their blood sugar to dangerous levels, resulting in hypoglycemia. It only takes a very small amount (around 100mg – that’s milligrams – per kilogram of body weight). Keep xylitol and food containing xylitol away from your pets!