Why Is There Plastic Grass In Sushi, Anyway?

One of the appeals of well-made sushi is the care in its preparation and presentation. From a perfectly sliced piece of toro to very specific plating protocol, the visual elements involved in serving sashimi or sushi aren't just attractive; they serve important purposes in enhancing the meal. For example, the white space of an empty plate around a piece of sushi helps draw attention to the fish, while the colors and flavors of different fish influence how pieces are plated and eaten (knowing how to savor different fish in the right order is a pro tip when it comes to eating sushi).

But what about that little green piece of plastic grass that shows up in a grocery store bento box, takeout orders, and sometimes even on a high-priced restaurant platter? Is it just decorative, or some sort of remnant tradition from days gone by? Actually, it's both — and more.

The original form of this unique garnish with decoratively cut jagged edges served multiple functions on a plate or box. The modern, vibrantly verdant plastic decoration mimics the fresh leaves from bamboo or other plants that were first used during the late Edo period (1600 to 1867) in Japan and are still common in nicer restaurants. Apart from adding a touch of color, one of its most important functions is separating the different pieces of food and their flavors in a multi-course bento box. You may hear that green sliver of plastic called bento grass, sushi grass, or baran, after one of the leaves that are commonly used.

Edomae sushi, basically what we call sushi today, first appeared in the early 1800s, and it seems the green leaf garnish appeared around the same time. The real leaves — called sasa or haran (or baran) depending on the plant species — are colorful, which was (and is) an important contrast to a dish dominated by red or white fish and white rice. The green is significant, as the leaves provide one of the five colors (goshiki) commonly represented in Japanese cuisine (red, yellow, blue or green, white, and black). As with so many traditional elements in cuisine, the leaves served multiple functions in a bento box or on a plate.

Historically, sasa bamboo leaves were more commonly used in Tokyo (previously known as Edo), while haran/baran (a flowering plant called Aspidistra elatior or iron plant) were favored in Osaka. When multiple pieces of sushi or sashimi are placed in a bento box or on the same plate, or with other foods, you don't want the flavors mingling. Since Sasa or haran leaves are plentiful, sturdy, and water resistant, the leaves are also sometimes placed on the bottom of a dish or bento box, preventing moisture or staining from setting in. Additionally, bamboo contains antibacterial agents, which can help keep foods (especially raw fish) safe to eat longer, which was especially important in the eras before refrigeration. The separation of specific groups of sushi or condiments also helps guide the diner when eating.

But why make the leaf all jagged? It's a visual reference to a fine art in Japan called sasagiri (or yama-kiri). In addition to adding a design element to the plate, it's a means of practicing knife skills as the real leaves used for sushi are hand-cut. In Japan, because of the two leaf types, you may see the terms sasa-kiri and haran-kiri used. In nicer restaurants, instead of the spiky grass cut, you may find them cut into all sorts of decorative elements, from butterflies to highly detailed cut-outs (think paper snowflakes).

Today, most takeaway spots and many restaurants (especially in the U.S., but also in Japan) swap in the plastic version for the real thing. They apparently appeared first in the 1960s when supermarkets popped up in Japan. The real leaves lose their color and texture after a couple of days, while plastic versions maintain their hue and are less expensive, both of which are important considerations for take-out spots. So it may be one of the differences you'll find between grocery store and restaurant sushi. The real leaves are also quite large, and the plastic "grass" can more easily be cut to custom sizes.

While the plastic versions don't offer antibacterial benefits, they still keep bites of sushi or other bento food separated in an attractive way and protect against moisture. You can buy plastic baran to decorate homemade sushi or sashimi, but if you get hold of the real thing (sasa bamboo grows well in parts of the U.S.), practice decorating using a yanagiba, the traditional Japanese knife used for cutting sushi.