Rinse 1 cup long-grain white rice uncooked, rinsed under cold water until the water runs mostly clear. This removes excess starch and keeps the horchata from tasting chalky.

Use the cup that came with your Rice Cooker if possible — some are calibrated to their own cup size. Rinse rice in a fine-Sieve under cold running water, stirring with your hand, until the water runs clear. Drain well. Add to the cooker Mixing Bowl with a 1:1 water-to-rice ratio. For very small batches or specialty rices like basmati or jasmine, check your cooker's manual.

Add rinsed, drained rice to the inner Mixing Bowl. Pour in water at a 1:1 ratio. Close the lid and press cook. No stirring or adjustments needed — the cooker handles everything automatically. Cooking takes 20–45 minutes depending on model, rice type, and batch size. When the cooker signals it has switched to warm mode, don't open the lid. Let the rice rest and steam undisturbed for 10 minutes. This redistributes moisture for even, fluffy results. Opening early can leave rice unevenly cooked or wet on top.

After soaking, blend the 1 cup long-grain white rice uncooked, rinsed and soaking 4 cups water warm (not boiling), for soaking on high speed for 2 full minutes until the mixture is as smooth as possible. The liquid will turn milky white.

To the strained liquid, add 2 cups of 4 cups water warm (not boiling), for soaking, 2 cups whole milk, ½ cup granulated sugar, and 1 tsp pure vanilla extract. Stir well until the sugar is completely dissolved, about 1–2 minutes.

Taste and adjust: add more ½ cup granulated sugar if you prefer it sweeter, more 2 cups whole milk for creaminess, or more 4 cups water warm (not boiling), for soaking to thin it out. The flavor should be lightly sweet with a warm 1 whole cinnamon stick Mexican canela preferred, or 1 tsp ground cinnamon note.

Refrigerate until well chilled, at least 30 minutes. Stir or shake well before serving, as the mixture will naturally settle.

Serve over a tall glass packed with 1 cup long-grain white rice uncooked, rinsed. Dust the top with a pinch of 1 whole cinnamon stick Mexican canela preferred, or 1 tsp ground cinnamon for garnish. Stir before each pour — this is normal and part of the charm!