Preheat the oven to 400 F.

On a rimmed baking sheet, spread the almonds out in a single layer. Toast in the oven for 4 minutes. Remove from the oven and let cool for about 5 minutes.

In a food processor, chop the almonds to a coarse grind (not the sand-like texture of almond flour).

Transfer the ground almonds to a large bowl and cover them with warm water. Let soak for 1 to 3 hours, depending on how strong you would like the almond flavor.

Using a fine-mesh strainer and two large layers of cheesecloth, squeeze all of the liquid from the almonds into a deep bowl. The almond pulp should be almost completely dry and youll have about 1 cup of liquid.

In a small saucepan over medium-low heat, gently warm the almond liquid. Whisk in the sugar and continue stirring until the sugar is completely dissolved, about 3 minutes. Remove from the heat.

Strain the orgeat syrup through two layers of clean cheesecloth. Stir in the orange flower water and, if using, the brandy or vodka and citric acid.

Once cooled, transfer it to a bottle with a tight lid. Refrigerate. Shake before using it in your favorite drinks.

Pulse the almonds in a food processor until finely ground. Set aside. Combine the sugar and water in a pot over medium heat and stir until sugar dissolves. Boil the syrup for 3 minutes, then add the ground almonds. Turn the heat to low and simmer for another three minutes, then slowly increase the temperature to medium-high. Just before it starts to boil, remove it from the heat and cover with a lid. Allow the covered nut mixture to infuse for at least 3 hours or up to 8 hours. Then strain it through 2 layers of cheesecloth, discarding the ground almonds for another use. Stir the brandy and orange flower water into the syrup. Use a small funnel to portion the orgeat into bottles or a jar. Seal and store in refrigerator for up to 2 weeks.