Rice milk + hojicha - why did it curdle?

Question

I'm trying to make "hojichata" (hojicha + horchata) with the intent of serving it over ice.

My thought was to either:

• Cold-brew the hojicha/cinnamon in the rice milk, then add sugar and vanilla.
• Brew the hojicha/cinnamon in the rice milk at somewhere around 175-200° F, add sugar and vanilla, then chill.

My first attempt at cold-brewing the hojicha in rice milk overnight seemed successful, but I mistakenly added powdered cinnamon towards the end and didn't really get as much cinnamon flavor as I was hoping. (Using powdered cinnamon also left a lot of sediment in the drink and seemed pretty unpalatable.)

For the second attempt (this time as a hot brew), I switched from powdered to chunks of cinnamon bark. After the rice milk hit about 150° F, it started to separate/curdle. I got it up to about 180° F before realizing that something was indeed Not Right.

The final product looks somewhat like miso soup in the bottle. It still tastes okay (and shaking it seems to redistribute it somewhat), but the mouthfeel definitely feels off and it looks pretty unsightly when it starts to settle.

Does anyone have ideas on what caused the rice milk to behave like this, and how to avoid it? I was under the impression that rice milk only curdled in presence of acid and heating it was otherwise OK.

Answer 1

From a couple searches, it seems that rice milk isn't recommended in hot beverages because it curdles when heated. (More sources: 2, 3)

A suggestion…

Make a hojichata tea concentrate and then dilute with rice milk.

1. Simmer cinnamon sticks in hot water to infuse, about ~10 min.
2. Add hojicha tea and brew for desired taste/time.
3. Strain out tea and cinnamon.
4. Add sugar and stir to dissolve.
5. Once cooled, combine tea concentrate with rice milk and vanilla (vanilla extract will evaporate when heated).
6. Enjoy!