exponential flavour extraction from strong herbs and spices

I’ve basically been asking as many people as possible this question for the past few months, and am slowly gaining some progress. Distillers, chefs, and experienced colleagues have given me answers that have pushed me slowly in the right direction as I continue the search. I have a solution, and it seems to be a more than adequate fix for the problem, but it’s my curiosity that is driving this question now. I want to know why.

This was first pointed out to me while I was cooking a rhubarb syrup that contains juniper berries. I had tripled my recipe, because I needed to make a huge batch that week. The sous chef was alongside me prepping for the evening service, and he noted that the syrup smelled different to usual. (We make this syrup weekly, so he’d become used to it on the stove for a few hours every Wednesday.) The aromatics of the juniper were much heavier than normal so as we chatted about it he suggested an idea that was wholly new to me: There was no need to multiply the amount of juniper in the recipe in proportion to the other ingredients, because it would continue to extract flavour at an exponential rate in a bigger recipe.

This was pretty confusing to me. I’m a pretty logical person, so this was a kind of frustrating wild card. How could I change the flavour when everything is the same, just bigger. But it’s not the same. Today, I finally considered that there is actually one variable. The recipe is being cooked for longer. The larger volume of water and rhubarb takes longer to heat, and longer for the rhubarb to break down, so the spice element is being infused for longer.

Special thanks to r/AskCulinary, where a user suggested to me that large volumes take longer to cool, so would continue infusing for longer. At first, I thought it wasn’t relevant because I strain the syrup as soon as possible while still hot, but actually it was just what I needed to take the tiny leap of considering the reverse of this.
And also to Mitch Keane, who distills for The West Winds Gin, for allowing me to pick his brains about the balancing act of capturing those strong spice flavours.

There are other ways that you could accidentally over infuse a recipe, which I’m still wrapping my head around, but I’m so pleased to have figured this one out.

pistachio syrup with xanthan

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.