Foods and beverages: apparatus – Cooking – Automatic control
Reexamination Certificate
2001-09-21
2002-12-03
Simone, Timothy F. (Department: 1761)
Foods and beverages: apparatus
Cooking
Automatic control
C099S348000, C099S355000, C099S44300R, C099S487000, C099S516000, C099S483000
Reexamination Certificate
active
06487962
ABSTRACT:
TECHNICAL FIELD
The present invention relates generally to large scale grain cookers, and more particularly to a method and apparatus for continuous controlled hydration grain cooking.
BACKGROUND ART
Rice is normally cooked in batches using what is known as a “full absorption method.” This entails placing a measured volume of rice in a vessel, submerging it in precisely the amount of water that the rice will absorb, and heating the water to a full boil. A measured amount of rice that matches the water in the vessel is then added to the water and the combination of water and rice is brought to a boil while simultaneously being mixed gently. Once the water is boiling the heat is turned down or off and the rice is allowed to sit in the water at a temperature of between 190-210° F. for approximately 20 minutes or until all of the water has been absorbed and the rice is fully hydrated and cooked.
This method is used for most types of rice, such as long-grained rice, medium- and short-grained ‘sticky’ rice, brown and basmati rice. Flavored rice is made by mixing flavorings such as turmeric or saffron into the water before the rice is added so that the rice will absorb the flavoring. Pilaf rice is also cooked in the same way by sauteeing onions, garlic and other herbs and spices, adding the water, bringing the water to a boil, and finally adding the rice to absorb the mixed ingredients.
A second method of cooking rice is termed the “excess water” method. In this method, the rice is added to a volume of water in excess of the amount the rice will absorb. At the end of the cooking process, when. the rice is fully cooked and hydrated, there will be some free water. The excess water method cannot be used in cooking Asian style ‘sticky’ rice because the excess water washes the starch from the surface of the kernels and leaves the rice less sticky. This method also cannot be used for cooking flavored rice or pilaf rice because the excess water dilutes the flavorings. Flavorings for rice are generally very expensive and it is desirable not to waste them by washing them away with the excess water.
The full absorption method of rice cooking is always used in batch cooking of rice. This method works reasonably well when the batch size is small (1-5 lbs. per batch). However, it does not work well when the batch size is several hundred pounds. This is because cooked rice on the surface of the batch has a lower water content than the rice on the bottom of the batch, rendering the batch of uneven quality. The unevenness occurs because as the rice kernels absorb water the kernels swell and the batch rises slightly out of the water pool. Once the top layer of rice has emerged from the water it cannot absorb additional water; at the same time rice kernels at lower levels in the batch with excess water around them continue to absorb additional water. When using this method, where the rice batch is 8-24 inches deep, the top layers have a much lower water content than the rice in the lower layers. In fact, rice at the bottom of the batch is over hydrated, soft and spongy; rice in the middle layers is generally hydrated properly, and rice near the top is under hydrated.
Continuous cooking of all cereal grain and cereal products, including rice, is much more efficient than cooking in batches. However, up to the present time true continuous cooking of rice could only be accomplished using the excess water method, and even then it was only used in cooking simple long grained white rice.
In Asia a semi-continuous full absorption cooking method is employed. The Asian medium- or short-grained types of rice are pre-soaked in water for one to two hours before cooking. Small pots are filled with a precise amount of water and pre-soaked rice, then conveyed through an oven to cook the rice in assembly line fashion. This system is very expensive and complicated to mechanize or to perform robotically for the following reasons: each pot must be filled with exactly the right amount of water and rice; the cover must be mechanically placed on the top of the cooking vessel; the pot is then conveyed through the oven; the cover is removed and the cooked rice tipped out; and the pot must then be washed and conveyed back to the beginning to receive another batch of rice and water. A machine to cook 2000 lbs. per hour of sticky rice presently costs in excess of $1,000,000 USD.
An additional disadvantage of this type of rice cooking system is that the rice is not stirred during the hydration time in the oven. As a result rice at the bottom of the pot has longer water contact time than rice at the top of the pot. Again, this results in uneven quality as the rice on the top layers have a lower water content than the rice kernels on the bottom layers. Accordingly, the result is much the same as that of the commercial batch cooking systems, with one difference: even the rice in the middle layers of the batch are generally not properly hydrated.
No other continuous full absorption method of cooking rice has been devised other than the assembly line pot method. Evidently no one has been able to conceive of a way to control the water and keep it in contact with each kernel until all rice kernels absorb the proper amount of water.
DISCLOSURE OF INVENTION
Generally: The present invention relates to a method of cooking cereal grains and products made of cereal grains in a batch cooker or continuously in a continuous cooker with controlled hydration. Also disclosed is an apparatus for the batch cooking of cereal grains and for the continuous cooking of cereal grains using the full absorption cooking method. Using the method and apparatus disclosed herein, a large bed of uncooked particulate cereal product is heated by direct steam injection without being in the presence of liquid water until the product is thoroughly heated to a temperature of approximately 190-200° F. Hot water, approximately 200° F. is then metered and periodically sprayed onto the top layers of the cereal at a rate slightly higher than the absorption rate of the food product, thereby allowing the water to percolate down through the cereal to the bottom layers at a rate matching the rate at which the product absorbs it during its vertical migration. The cereal in its fully heated condition begins to absorb the water that coats the surface of the cereal kernels. By periodically metering and spraying more water onto the cereal grain layers at a rate slightly above the rate at which the hydrating kernels absorb the water, the kernels throughout the volume of product will hydrate at an optimal rate.
In a continuous cooker this process is employed while the cereal is conveyed horizontally from an inlet end of the cooker toward the discharge or outlet end. At the discharge end of the cooker the cereal grains are fully hydrated and have absorbed all of the cook water sprayed onto the kernels during its transit through the cooking apparatus.
Although this invention applies to any cereal grain (such as rice, wheat, oats, corn, etc.) or any product made from cereal grain (such as pasta, oat meal, risotto, etc.) the instant application refers to rice for purposes of illustration and example only.
The full absorption batch or continuous rice cooking process and apparatus of the present invention will produce high quality rice at a fraction of the cost of existing batch or continuous assembly line pot cooking systems. It can cook Asian short grained ‘sticky’ rice, flavored rice and pilaf rice. The cooking process is controlled precisely to result in the same quality as batch cooked rice.
Summary of the Inventive Method: Each type of rice has a sequence of stages in the full absorption cooking process: First, either immediately preceding or as product is loaded into the cooking vessel, the rice kernels are washed for approximately four minutes to remove dust and surface starch. This is an optional but preferable stage; i.e., the rice need not be washed before cooking. The washing is accomplished by spraying water onto the rice at a high rate through at least one nozzle and while the
Johnson Larry D.
Johnson & Stainbrook LLP
Simone Timothy F.
Stainbrook Craig M.
LandOfFree
Apparatus for controlled hydration grain cooking does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for controlled hydration grain cooking, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for controlled hydration grain cooking will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2923490