Red Shiso Juice (赤紫蘇ジュース, Akajiso Jūsu)

Ingredients

Equipment Needed

• •Large pot
• •Fine-mesh strainer
• •Sarashi cotton cloth, or a clean thin kitchen towel
• •Clean heatproof bottles or jars

Instructions

1. 1

   Wash the leaves

   Strip the red shiso leaves from the stems and put them in a large bowl of cold water. Swish them well, lift them out, and change the water until no grit settles at the bottom. Red shiso grows close to the soil, and grit has no business in a clear drink. Drain the leaves in a basket, but don't worry about drying them perfectly.

2. 2

   Simmer the shiso

   Bring the 2 liters of water to a boil in a large pot. Add the leaves by handfuls, pressing them under the surface with chopsticks or a wooden spoon. Simmer gently for 5 to 7 minutes, until the leaves turn dull green and the water is deep purple. That color change is not failure. It means the leaf has given the pot what you asked of it.

   Keep this to a gentle simmer. A hard, long boil pulls out a rough grassy taste, and this drink should be sharp and clean, not cooked to death.
3. 3

   Strain it clean

   Set a fine-mesh strainer lined with sarashi cotton or a clean thin cloth over a heatproof bowl. Pour in the shiso liquid and leaves, then press the leaves gently with a ladle to recover the colored liquid. Don't wring the cloth hard. A little pressure is sensible, but mashing the leaves brings bitterness along with the last spoonful.

4. 4

   Dissolve the sugar

   Return the strained liquid to the pot while it is still hot. Stir in the sugar until fully dissolved, then bring it just back to a quiet simmer for 2 minutes. Sugar dissolves cleanly in heat, and this short simmer helps the concentrate keep without driving off the shiso's perfume.

5. 5

   Brighten with acid

   Take the pot off the heat and stir in the lemon juice and rice vinegar. The color will shift from dark purple to clear crimson almost at once. Taste it now. It should be too strong, too tart, and a little too sweet to drink straight, because ice and cold water will soften everything later.

   Add the acid off the heat. You want the brightness and scent of lemon and vinegar, not their boiled shadow.
6. 6

   Bottle and chill

   Pour the hot concentrate into clean heatproof bottles or jars. Let it cool until just warm, cap it, and refrigerate until cold, at least 2 hours. This is a lightly sweetened drink, not a shelf-stable syrup, so keep it cold and use it within 10 days, or freeze what you want for later summer.

7. 7

   Dilute to serve

   For each glass, pour 1 part red shiso concentrate over ice and add 1 to 2 parts cold water. Stir, taste, and adjust with more water if needed. Serve it bright and cold, with nothing hidden and nothing piled on top.

Chef Tips

• •Buy red shiso when the leaves look lively and matte, with a strong herbal scent when you rub one between your fingers. If the bunch smells tired or the stems are woody, choose another day. Sourcing first, always.
• •If you can, use rice vinegar for the vinegar portion. Lemon gives the high clear edge, while rice vinegar steadies the acidity in the way we expect at a Japanese table.
• •Do not reduce this like a heavy syrup unless you want a different drink. Red shiso's charm is its clear fragrance, and long boiling flattens it.
• •For outdoor dining, carry the concentrate in one bottle and cold water in another. Dilute at the table so the drink stays vivid and the ice doesn't exhaust itself before anyone drinks.

Advance Preparation

• •The concentrate keeps up to 10 days refrigerated. Because this version is lightly sweetened, don't store it at room temperature.
• •For late-summer drinking, freeze the concentrate in small jars or ice cube trays for up to 3 months.
• •The shiso leaves can be picked through and washed a day ahead. Wrap them loosely in a damp towel and refrigerate, then simmer them the next day while their scent is still fresh.

Frequently Asked Questions

Nutrition Information

1 serving (about 150g concentrate)