Methods of and systems for a dry milling process with two steps liquefications

1 . A dry milling process comprising:

a liquifying starch in floury endosperm from milled corn kernels making a liquefied starch slurry in a first liquefication tank having a slurry of 20-27 Be;

b. performing solid/liquid separation forming a liquid portion and a solid portion;

c. sending the liquid portion containing the starch in the floury endosperm to a fermenter;

d. sending the solid portion for reducing a density of the slurry of 20-27 Be to a slurry <5 Be by using a washing water from backset stream after the first liquefication tank and before a second liquefication tank, wherein the solid portion comprises grit and germ particles;

e. soaking, cooking, or degrading protein using a protein cell wall degrading enzyme in the second liquefication tank having the slurry <5 Be, wherein the protein cell wall degrading enzyme contains cellulase, protease, cell wall degrading enzymes, or a combination of thereof;

f. performing wet grinding after the second liquefication tank to break up and release starch in horny endosperm and oil; and

g. liquefying starch in the horny endosperm in the second liquefication tank having the slurry <5 Be.

2 . The dry milling process of claim 1 , further comprising performing a holding time on the first liquefication tank between 1 to 2 hours.

3 . The dry milling process of claim 1 , wherein the soaking, cooking, or degrading the protein is performed for 2 to 4 hours.

4 . The dry milling process of claim 1 , further comprising performing a first solid/liquid separation between the liquifying starch at the first liquefication tank and the soaking, cooking, or degrading protein at the second liquefication tank.

5 . The dry milling process of claim 4 , further comprising using a back set stream as the washing water to perform a displacement washing at the first solid/liquid separation.

6 . The dry milling process of claim 5 , further comprising performing the displacement washing at the first solid/liquid separation until a content in a first paddle screen becoming the slurry <5 Be.

7 . The dry milling process of claim 1 , further comprising performing a second solid/liquid separation after the soaking, cooking, or degrading protein at the second liquefication tank.

8 . The dry milling process of claim 7 , further comprising using a cook water as washing water in a second paddle screen to wash off small germ and grit particles.

9 . The dry milling process of claim 8 , further comprising producing DDG in a form of a wet cake by mixing pure fiber from the second paddle screen with a portion of a whole stillage.

10 . A dry milling process comprising:

a. liquifying starch in floury endosperm from milled corn kernels making a liquefied starch slurry in a first liquefication tank having a slurry of 20-27 Be;

b. performing solid/liquid separation forming a liquid portion and a solid portion;

c. sending the liquid portion containing the starch in the floury endosperm to a fermenter;

d. sending the solid portion for reducing a density of the slurry of 20-27 Be to a slurry <5 Be by using a washing water from backset stream after the first liquefication tank and before a second liquefication tank, wherein the solid portion comprises grit and germ particles;

e. degrading protein using a protein cell wall degrading enzyme in the second liquefication tank having the slurry <5 Be, wherein the protein cell wall degrading enzyme contains cellulase, protease, cell wall degrading enzymes, or a combination of thereof;

f. performing wet grinding after the second liquefication tank to break up and release starch in horny endosperm and oil; and

g. liquefying starch in the horny endosperm in the second liquefication tank having the slurry <5 Be.