How to stop erythritol crystallisation?

Question

While making a "sugar" syrup reduction with erythritol, I have noticed that the liquid crystallises upon cooling. Google-fu says two parts of water and one part of erythritol will not crystallise. The two challenges with this are : One, upon boiling, the water content is sure to reduce so the ratio is out of the window and the important one is that the sweetness is diluted and hence reduced. The solution to bumping up the sweetness is to add in a few Stevia drops.

I now have access to some sunflower liquid lecithin - will adding 23 milliliter to one cup of water and one cup of erythritol avoid crystallisation? First time using lecithin - from reading on the internet lecithin will hold on to water and oil. There is no oil in this recipe. But people have used to stabilise xylitol based sugar syrups - hence the question.

How do I make a sugar syrup with erythritol that doesn't crysatllise?

Answer 1

This is simply the nature of erythritol. In my testing, I wasn't able to create any kind of viscous, syrup-like consistency by mixing it with water and heating it to reduce; rather, it would always form a hard crystalline structure. This most likely has to do with the fact that, unlike regular sugar (sucrose), erythritol is not hygroscopic at all. (Things that are hygroscopic like to hold onto moisture for dear life; erythritol simply lets go of the moisture and you end up with a hard crystal).

If you are in the US, I'd recommend looking into allulose. It's extremely hygroscopic and I've successfully used it to create a syrup-like consistency. (On a scale from 1 to 10 — 1 being the least hygroscopic and 10 being the most — if erythritol is about a 3, allulose would be a 9 or 10). Be careful, however, as it burns much more easily than regular sugar does. Some downsides of allulose are that it's more expensive than erythritol and it isn't approved in the EU.

I have less experience with xylitol, but I believe it is also hygroscopic enough to be able to form a syrup, but I'm not positive. (Just a note in case anyone wasn't aware: xylitol can be fatal to dogs and cats). I did one test with xylitol but had problems with it crystalizing, but after reading the guidelines at https://willamettetransplant.com/xylitol-simple-syrup/, I realized I likely wasn't careful enough in creating the syrup. It seems any undissolved crystals or stray crystals that come in contact with the syrup can serve as seed crystals to hasten re-crystalization.

Answer 2

Distilled water helps reduce crystals. Using powdered erythritol added at the end of boiling the water does too. Mixing a bit of xanthan gum helps (spruce eats simple syrup but make sure you mix it with the powdered erythritol first).