Methods and system for wheat milling
Processes and systems for commercial scale milling of wheat are disclosed. Processes include multiple tempering steps of controlled duration and cubing of the wheat kernel between two tempering steps. The cubing between the tempering breaks the kernels, or stresses the kernels, in a manner that enables a high degree of separation of the bran and endosperm early in the flour production process. An embodiment includes tempering for a first period between hour and 2 hours, cubing in a roll crusher with longitudinal corrugations on one roll and circumferential corrugations on a second roll, removing fines from the cubed kernels, and further tempering of the cubed kernels for a period between hour and 2 hours.
1. A process for producing flour from wheat kernels having outer bran, inner endosperm and inner germ, the process comprising:
a. tempering at least 4½ metric tons per hour of the wheat kernels in a first temper mix for a first time period between about ½ hour and about 2 hours;
b. cubing the wheat kernels to form cubed kernels such that at least 80% by weight of the kernels will not pass through a 1800 micron size mesh, the cubed kernels including bran and endosperm, said cubing generating fines;
c. sifting to remove at least some of the fines;
d. tempering the cubed kernels for a second time period between about ½ hour and about 2 hours, wherein a total tempering time equals the first time period plus the second time period, and wherein the total tempering time is less than or equal to 4 hours; and
e. milling the cubed kernels through a sequence of rollers to produce flour.
2. A process for producing flour from wheat kernels having outer bran, inner endosperm and inner germ, the process comprising:
a. tempering at least 4½ metric tons per hour of the wheat kernels in a first temper mix for a first time period between about ½ hour and about 2 hours;
b. cubing the wheat kernels to form cubed kernels such that at least 80% by weight of the kernels will not pass through a 1800 micron size mesh, the cubed kernels including bran and endosperm, said cubing generating fines;
c. sifting to remove at least some of the fines;
d. tempering the cubed kernels for a second time period between about ½ hour and about 2 hours, wherein a total tempering time equals the first time period plus the second time period, and wherein the total tempering time is less than or equal to 4 hours, wherein tempering the cubed kernels for a second time period further includes using a moving temper during a portion of the second time period and
e. milling the cubed kernels through a sequence of rollers to produce flour.
3. The process of claim 2 , wherein the second time period is approximately six to ten minutes.
4. The process of claim 1 , wherein sifting to remove at least some of the fines further comprises removing material finer than about 900 to 1200 microns in size.
5. The process of claim 1 , wherein the tempering for a first time period comprises passing the wheat kernels through a first in, first out temper bin.
6. The process of claim 1 , wherein the process of milling the tempered cubed kernels through a sequence of mill rollers into flour is controlled by a feedback based on the moisture content of the flour.
7. The process of claim 1 , wherein each of the first time period and second time period is between about ½ hour and 1½ hours.
8. A process for producing flour from wheat kernels having outer bran, inner endosperm and inner germ, the process comprising:
a. tempering at least 4½ metric tons per hour of the wheat kernels in a first temper mix for a first time period between about ½ hour and about 2 hours;
b. cubing the wheat kernels to form cubed kernels such that at least 80% by weight of the kernels will not pass through a 1800 micron size mesh, the cubed kernels including bran and endosperm, said cubing generating fines, wherein cubing the wheat kernels comprises passing the wheat kernels through a roll crusher having generally longitudinally oriented corrugations on one roller and generally circumferentially oriented corrugations on an opposing roller;
c. sifting to remove at least some of the fines;
d. tempering the cubed kernels for a second time period between about ½ hour and about 2 hours, wherein a total tempering time equals the first time period plus the second time period, and wherein the total tempering time is less than or equal to 4 hours; and
e. milling the cubed kernels through a sequence of rollers to produce flour.
9. The process of claim 8 , wherein the longitudinally oriented corrugations are at a spiral angle of between about 2% and about 4%.
10. The process of claim 1 , wherein cubing the wheat kernels separates germ contained in the wheat kernels and further comprises, after the further tempering, sifting to capture at least some of the germ.
11. The process of claim 1 , wherein cubing the wheat kernels further comprises producing cubed kernel segments, and wherein a portion of the cubed kernel segments comprise exposed endosperm.
12. The process of claim 2 , wherein the moving temper comprises at least one of a moving conveyor, a belt system, an auger, a screw, and a screw conveyor.
13. The process of claim 1 , wherein the step of sifting to remove at least some of the fines comprises sifting the cubed kernels into at least one of a coarse fraction, a medium fraction, and a fine fraction.
14. The process of claim 13 , wherein the step of sifting to remove at least some of the fines comprises sifting the cubed kernels into at least two of a coarse fraction, a medium fraction, and a fine fraction.
15. The process of claim 14 , wherein the step of sifting to remove at least some of the fines comprises sifting the cubed kernels into a coarse fraction, a medium fraction, and a fine fraction.
16. The process of claim 15 , wherein the coarse fraction comprises cubed kernels approximately 1200 microns or larger, wherein the medium fraction comprises cubed kernels from approximately 500 microns to approximately 1200 microns, and wherein the fine fraction comprises cubed kernels below approximately 500 microns.