For a while I was looking for a method to get my pistachio syrup stable, be it cloudy or clear, without using metres of muslin cloth. (pistachio syrup with xanthan). I actually solved this a little while back and after making it a few times have pretty much nailed down an easy method.
The recipe I was using had a splash of unexplained vinegar in it. For most of the time I have been making it I assumed it must have been included as a preservative measure, as with shrubs, as there was no mention of it in the recipes method. One day however, as I was melting sugar into my pistachio milk on the stove, I noticed a thick skin forming on the top of the liquid, and I began to skim it off, as you might while clarifying butter. So many things clicked in my brain at the same time (citric acid in cheesemaking, alternative milks like soy and almond curdling in hot coffee) and that unexplained splash of vinegar suddenly made sense.
Now I bring that stuff to the boil, stand over it at a simmer with a large flat spoon, and skim as much of that gunk from the surface as I can, and then it’s just one pass through few layers of muslin for a perfectly clear syrup. I wouldn’t necessarily use vinegar in every orgeat recipe I made. In this recipe it works because the pistachio syrup is used in combination with a shrub that also contains the same type of vinegar, so the distinctive flavour is balanced in the final drink. It’s definitely worth looking into how small an amount of acid you can add to encourage it to curdle, to reduce the chances of altering the flavour.
I really want to batch my pistachio syrup in with my more stable ingredients without the oil separating out. The bottle looks so gross as it settles, and then if the batch is left too long the fats start to solidify around the neck. The syrup does the same on its own, and the clear syrup left after the milky solids have risen looks beautiful and tastes amazing, but I don’t want to lose up to half of my volume skimming the top off to get to that. I can accept that my syrup will probably be milky and opaque.
If I could be bothered straining the seemingly never ending tiny particles of nut then I might have something a little prettier, but I also don’t want to spend hours on the clarification of one syrup, and it’s kind of important to me that I keep that oily texture to some extent. When you’re eating or drinking something you can tell if it’s creamy, but potentially that’s a different thing to actually tasting the fats that make it creamy. Researchers at Deakin University in Victoria, Australia, have suggested that fat could be the sixth flavour that we can perceive, alongside salty, sweet, sour, bitter and umami. (foodnavigator)(flavourjournal).
I can batch commercially produced orgeat without separation being a problem, so the solution has got to be in the emulsifier. I’m still figuring out the practical applications of xanthan gum but I know I have a one major potential problem to avoid… If I add too much xanthan then the syrup will be incredibly thick, maybe even jelly-like, which will alter the texture of the drink it’s used in. I’m really happy with the flavour profile already, so I don’t want to drop my sugar content to make room for more viscosity. Looking ahead, what if I can stabilize the syrup, but then it won’t bond in the batch. Well, then I guess it’s not really stable, and it’ll be back to the start.
So for now, I have set aside 200mL of my already prepared pistachio syrup mixed with 0.1g of xanthan, (I know I should have weighed that pistachio syrup. I always do this to myself, mixing my units of measurement), so I’m using between 0.05% and 0.1% of total ingredients. The swelling of the xanthan had already added 30mL to my total volume when I left it to refrigerate though. I’ve left it for 24 hrs to allow time for it to separate if it’s going to.