Irregular homemade horchata with optional pandan and sweet fermented rice

Generally speaking, horchata is a dairy free milky drink (though dairy milk may be added nowadays) made from various nuts, seeds, and grains depending on where in the world you're drinking it. The horchata recipe at the end of this post is based on a Yucatecan (of Yucatán, in Southeastern Mexico) style rice and almond blend. ⁠I've included a few optional extras (pandan and/or sweet fermented rice) and explain why I believe these ingredients pair well with horchata.

What type of rice should you use to make horchata?

My preference is for an aromatic rice. This category of rice is distinctive, not just ornamental in name, because these varieties contain high concentrations of the volatile molecule acetyl pyrroline. This molecule is responsible for the popcorn-like aroma many people perceive as the flavour of rice. Other types of rice contain acetyl pyrroline, but in perhaps imperceptible quantities.

When I refer to acetyl pyrroline as volatile, what I mean is the molecules are able to evaporate and fly away, eventually dissipating. This is how we smell foods, from molecules in the air that enter our odor receptors. Heat encourages volatility and this is why we can smell a stew from the other side of the house but not the component ingredients before high temperature is applied.

You may have seen recipes where you are encouraged to soak rice before cooking it. Now you understand what volatility means and how it can be promoted by cooking, it makes sense to take steps that would help you to shorten the cooking time. Soaking rice does just that and thus helps to preserve its delicate aroma.

You can also use any long grain rice to make horchata, and probably with results that best mimic the flavour of traditional Mexican styles of this rice based agua fresca (a category of sweet, refreshing Mexican beverages that translates as cool/fresh water). Long grain brown rice is also fine and will impart a pleasantly fruity-nutty flavour.

Pandan leaf as a flavour intensifier

But, as usual, I digress. Back to my preference for aromatic rice because of its musky popped corn aroma, I also love pandan for the same reason. You may have seen recipes for cooking jasmine rice that include steaming the grains with knotted pandan leaf. Because pandan also contains acetyl pyrroline, the combination of ingredients enhances that popcorn flavour.

Additionally, pandan contains dilly dallying, aroma-persistent sotolon. This is present in extremely high levels in fenugreek seeds, and has a kind of maple syrup aroma. In fact, artificial maple syrups used to contain fenugreek seeds as a flavour base prior to the existence of sotolon as a prominent tool in today’s flavour chemistry. Anyway, sotolon is the source of the lovely sweet and caramelly notes in pandan leaf. That plus its concentration of acetyl pyrroline makes it a wonderful component ingredient in horchata.

Optional addition of fermented sweet rice

Khao mak is an out of fashion Thai (also made in other East Asian countries, such as in China where it is called laozao) sweet made by mixing steamed glutinous rice with sugar and a special type of dried yeast and mould blend. Over the course of a few days, the starch in the rice converts into sugars and then the sugars into lactic acid and alcohol. The result is a sweet, fermented, minimally alcoholic comfort food best served cold. 

I’m not sure what component of the process is responsible, but I find fermented sweet rice often bears a flavour reminiscent of cinnamon. This is why I thought to pair it with horchata, which literally includes cinnamon in its making.

You can buy jars of khao mak premade in many East Asian grocers (especially Vietnamese and Chinese), usually not too far from the yeast/mould cakes you can also purchase in order to make the rice ferment yourself.

📖 Recipe

Print Recipe

Mexican-Thai Fusion Horchata

Horchata refers to any number of nondairy milks made in parts of both Europe and Africa, as well as in the Americas. This horchata recipe is based on a Yucatán style with blended rice and almonds, with an optional Southeast Asian pandan element and/or the addition of a type of sweet fermented rice found across East Asia. This doesn't keep for long (somewhere between 2-4 days in the fridge) so drink up!

Course: Drinks

Cuisine: Mexican, Thai

Servings: 950 millilitres

Equipment

• Blender

Ingredients

• 85 grams long grain white rice ½ cup
• 2-3 inch long pieces cinnamon stick
• 50 grams whole almonds ⅓ cup
• 1 litre water
• 110 grams white sugar slightly rounded ½ cup (more if you like it very sweet, less if you don't)
• 1 ½ teaspoons vanilla extract
• ½ teaspoon almond extract optional
• ¼ teaspoon fine salt
• Ice

Optional extras

• 4-6 pandan leaves cut into 1 inch pieces
• Khao mak ข้าวหมาก or laozao optional

Instructions

• Toast the rice and cinnamon stick together in a dry pan until the rice is golden and emits a nutty aroma¹. Tip into a large bowl, along with the almonds and water. Cover with a plate or towel and leave to soak overnight.
• The next morning, tip all of the contents of the bowl into a blender jug. Unless you have a powerful vortex blender such as a Vitamix, remove the cinnamon first. Add the sugar, vanilla extract, optional almond extract, and salt. Blend on high speed until the rice and almonds have broken down as finely as possible and the sugar has dissolved. Taste for sweetness and add more sugar if desired.
• Strain using either a very fine mesh or a muslin cloth. To avoid wasting the pulp, see my notes for how you can use it².
• Store in the fridge. Horchata is best served ice cold, so to serve just fill a glass with ice and then pour horchata to the brim.

Pandan option

• Make the recipe as above, but remove the cinnamon before blending. You can also omit the vanilla and almond extract if you’d like (it’s good either way).
• Once the horchata is strained, add around 250 millilitres (1 cup) of the liquid back to the blender, along with 4-6 pandan leaves that have been cut into 1 ½ centimetre (½ inch) pieces. Blend on high speed until the leaves break up as finely as possible and the horchata turns green.
• Use muslin to strain this liquid back into the rest of the horchata. Discard the pandan leaf pulp.

Khao mak option

• Add 2-4 tablespoons khao mak in the bottom of your glass before topping up with ice and horchata. It’s fine enough to drink with a normal straw or you can eat it with a spoon.

Notes

1. Toasting the rice and cinnamon is optional, but adds an additional nutty layer to the horchata.
2. There is no need to waste the rice and almond pulp. You can make a congee like porridge or a thicker dessert by cooking the sediment with non dairy milk (the amount depends on the consistency you’d like) of your choice. I pop it all in my Instant Pot and pressure cook it for 10 minutes, and then serve with chunks of jaggery or piloncillo/panela (unprocessed cane sugar) and soy cream. Just be careful of any chunks of cinnamon that may not have broken down finely when blending. I have also had success baking the pulp into sourdough and/or yeasted pita breads.

If you are interested in the science of food and want to learn more, I highly recommend the following books: