All About Rice – Cooking Rice

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• All About Rice – Washing Rice
• All About Rice – Cooking Rice

Rice, originating from Asia, serves as a fundamental dietary cornerstone for a significant portion of the global population. Its various species, with Oryza sativa being the most recognized, offer a diverse range of culinary options.

The outermost layer, known as chaff, acts as a protective shield, shielding the seed from harsh environmental conditions. Typically discarded during processing due to its toughness.
Beneath the chaff lies the bran, a fibrous layer rich in nutrients and healthy fats. While high in dietary fiber, it requires processing for optimal digestibility.
The germ, situated beneath the bran, serves as the seed’s reproductive core, packed with essential genetic information, nutrients, and fats.
Constituting the majority of the grain, the endosperm envelops a portion of the germ and primarily provides starch for energy.

• Brown rice
  It retains the bran and germ, which are nutrient-dense but affect its texture and shelf life due to their composition.
• White rice
  It consists solely of the endosperm after removing the chaff, bran, and germ, offering a starch-rich composition.

Rice, primarily composed of starch in semi-crystalline granules, undergoes a fascinating change when subjected to heat and moisture. These starch granules undergo a process called gelatinization. This transformation involves swelling and softening, relinquishing their rigid, crystalline structure.

Complete gelatinization results in soft, delectable rice, while incomplete gelatinization leaves it undercooked with a slight crunchiness. Continued heating post-gelatinization initiates the breakdown of the swollen starch granules.

Pasting describes the elevation in the liquid’s thickness due to agitation. Essentially, stirring the gelled rice results in stickiness and, in severe instances, a mushy texture. Stirring action disrupts some of the swollen starch granules, causing starch molecules to seep into the nearby liquid, enhancing stickiness and viscosity.

Excessive pasting leads to overcooked rice—rendering it soft and disintegrated.

Rice comprises two primary starch types: amylose and amylopectin, both intricate carbohydrate structures made of glucose molecules.

• Amylose
  It forms a straight chain exhibits lower solubility in water, failing to readily form a gel or thicken hot water.
  Rice varieties rich in amylose tend to yield more individual grains after cooking, with minimal stickiness between them.
• Amylopectin
  It boasts a highly branched configuration. This structural contrast results in diverse textures in cooked rice. It dissolves more readily, augmenting the viscosity of the surrounding water.
  Rice containing a higher proportion of amylopectin tends to produce stickier grains, with less distinction between them.

When considering cooking methods, we can broadly categorize rice grains based on their length and corresponding amylose-amylopectin content, offering insights into the resulting cooked rice texture.

Long-grain varieties typically yield more distinct grains with minimal stickiness. Yet, it’s crucial to note that each rice type, including specific cultivars and growth conditions, possesses its own unique amylose-amylopectin content, size, and flavor. Therefore, general statements may only provide a starting point for understanding their varied characteristics.

Further complicating the rice options, one might encounter products like converted or enriched white rice while browsing at the local store. Converted, also known as parboiled, rice undergoes a unique process—it’s precooked while still in its husk. This method involves complete gelatinization followed by cooling, drying, and milling to remove the husk, bran, and germ. Often, minerals are infused to boost nutritional content. The parboiling process effectively transfers nutrients from the bran and germ to the endosperm. As a result of cooling, termed retrogradation, starch molecules form dense structures. Converted rice requires less cooking time and yields grains that are notably separate, devoid of stickiness, and don a yellow-to-brown hue from husk and bran pigments. Ben’s Original Rice is a well-known example.

Then there’s enriched rice, a straightforward addition of vitamins and minerals during processing to heighten its nutritional profile. In less developed regions, enrichment has served as a crucial measure against malnutrition, addressing ailments such as pellagra caused by niacin deficiency.

The key principles guiding any strategy involve boiling and/or steaming. Both techniques involve the introduction of water and heat—essential components for starch gelatinization.

It is often likened to cooking pasta. By boiling rice in a significant amount of water, ample water supply ensures proper gelatinization. Post-cooking, the rice is drained and allowed to rest until it reaches readiness. This technique typically yields individual, distinct grains, particularly suitable for varieties like basmati known for their elongated grains.

Ideal for low-amylose grains such as Thai sticky rice, this gentle cooking process minimally disrupts the grains compared to vigorous boiling. However, it’s not a commonly employed method for long-grain rice.

Rice is cooked in a precise amount of water in a saucepan on the stovetop. As the rice absorbs water, residual steam assists in the gelatinization process. This method offers a balance between effectiveness and convenience for various rice types.

Apparently, in perfectly sealed environment, rice only needs equal amount of water in volume to cook through. Unfortunately few of us have or willing to cook ricer in a perfectly sealed pot so we simply compensate for the lost amount of water by adding a bit more to it so when we cook a cup of rice we only need 1¼ cup water to cook the rice.

Of course personal preferences vary about stickiness but rice doesn’t need a lot of water to be cooked through.

Timing

Research indicates that the degree of gelatinization depends significantly on both time and temperature. Studies suggest the gelatinization temperature for rice ranges from 154°F to 174°F (68-79°C), contingent on the rice variety.

During stovetop cooking, the rice pot typically reaches boiling point (212°F/100°C at sea level). Beyond the water-to-rice ratio, the critical variable becomes timing. The longer the rice cooks—assuming it has absorbed most, if not all, of the water—the greater the gelatinization, resulting in softer grains.

Rinsing rice eliminates loose surface starches but it doesn’t have any effect on the end results. It also eliminates any unwelcome debris and potential off-flavors they might bring.

Soaking supposedly reduces cooking time by aiding water absorption and starch swelling beforehand but it requires several hours.

Salt plays a crucial role in seasoning. But salt hinders the gelatinization of rice starch when cooked. The effect varies based on salt concentration.

More salt competes with starch for available water, reducing the water’s capacity to gelatinize starch.

Similar principles apply to nonvolatile solutes like sugar. However, in practice the impact is negligible because up to 10% of water weight of salt is required to produce a noticeable effect.

Fat and Rice

Certain cooks incorporate oil or butter into rice, either directly into the cooking liquid or by toasting grains in fat. Fats work to delay the swelling of starch granules, aiming to create more individual grains.

Rice cooked with added fat in the liquid showes slightly reduced stickiness. As for rice toasted in fat, it resulted in more distinct grains, reminiscent of rice pilaf or parboiled rice. This aligns with the technique used for risotto, where toasting aids in breaking down the exterior starch of the rice.

Summary

• Rice can be cooked to taste, which could mean either separated grains or sticky ones.
• To cook 1 cup of rice, it needs only 1¼ cup water (100g rice needs 150g water). More water will make stickier rice.
• Longer cooking time results softer grains.
• Rinsing rice has no effect on cooking time or the end results. See: All About Washing Rice