**Exhibit 10.4**

**PARENT GUARANTY**

Aventine Renewable Energy- Aurora West, LLC, a Delaware company (“Owner”), and Kiewit Energy Company, aDelaware corporation (“Contractor”) entered into an EPC Fixed Price Contractdated May 31, 2007 (the “Agreement”).

**WHEREAS,**Owner is an indirect wholly-owned subsidiary of AventineRenewable Energy Holdings, Inc., a Delaware corporation (the “Guarantor”); and

**WHEREAS,**Guarantor will derive direct and indirect benefit from Ownerentering into the Agreement; and

**WHEREAS,**as a condition to Contractor’s entering into the AgreementContractor requires that Guarantor execute this Parent Guaranty

**NOWTHEREFORE,**Guarantor agrees as follows:

1.                          Guarantorirrevocably guarantees the full and timely performance by Owner of all itsobligations, terms, provisions, conditions, and stipulations under theAgreement, as now or hereafter amended (the “Obligations”), and herebyundertakes that if Owner shall in any respect fail to pay, perform and observeall of the Obligations of the Agreement, Guarantor shall (i) pay or perform orhave paid or performed all Obligations as required by the Agreement, withoutany requirement that Contractor first proceed against Owner, and (ii) reimburseContractor for any expenses incurred in enforcing its rights under this ParentGuaranty against Guarantor, in each case upon five (5) business days followingGuarantor’s receipt of written notice of Owner’s failure to pay or perform anObligation, or an itemization of such expenses incurred. This Parent Guarantyconstitutes a guarantee of payment when due and not of collection.

2.                          Theobligations of Guarantor under this Parent Guaranty shall be primary, absoluteand unconditional obligations of Guarantor, independent of the obligations ofOwner, shall not be subject to any counterclaim, set-off, deduction,diminution, abatement, recoupment, suspension, deferment, reduction or defensebased upon any claim Guarantor may have against Owner. To the fullest extentpermitted by applicable law this Parent Guaranty shall remain in full force andeffect without regard to, and shall not be released, discharged or in any wayaffected by:

(a)                     anytermination, amendment or modification of or deletion from or addition to orother change in the Agreement or any other instrument or agreement applicableto any of the parties to the Agreement;

(b)                    anyvoluntary or involuntary bankruptcy, insolvency, reorganization, arrangement,readjustment, assignment for the benefit of creditors, composition,receivership, conservatorship, custodianship, liquidation, marshaling of assetsand liabilities or similar proceedings with respect to Owner, Guarantor,Contractor or any other person or any of their respective properties orcreditors, or any action taken by any trustee or receiver or by any court inany such proceeding;

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(c)                     anymerger or consolidation of Owner or Guarantor into or with any othercorporation, or any sale, lease or transfer of any of the assets of Owner orGuarantor to any other person;

(d)                    anychange in the ownership of any interests of Owner or any change in therelationship between Owner and Guarantor, or any termination of suchrelationship;

(e)                     anyfailure of Owner to conform with any provision of the Agreement or any otheragreement; or

(f)                       anyfailure or delay on the part of Contractor to enforce any right under theAgreement.

3.                          TheGuarantor unconditionally waives, to the extent permitted by applicable law,

(a)                     noticeof any of the matters referred to in Section 2;

(b)                    noticeto Guarantor of any breach or default with respect to the Agreement or anyother notice that may be required, by statute, rule of law or otherwise, topreserve any rights of Contractor against the Guarantor;

(c)                     anyrequirement to exhaust any remedies;

(d)                    anyother circumstance whatsoever which might otherwise constitute a legal orequitable discharge, release or defense of a guarantor or surety or which mightotherwise limit recourse against Guarantor.

4.                          ThisParent Guaranty shall continue to be effective or be reinstated, as the casemay be, if at any time payment, or any part thereof, to Contractor isrescinded, invalidated, declared to be fraudulent or preferential, or mustotherwise be returned, refunded, repaid or restored by Contractor upon theinsolvency, bankruptcy, dissolution, liquidation or reorganization of Owner orGuarantor or upon or as a result of the appointment of a receiver, intervenoror conservator of, or trustee or similar officer for, Owner or any substantialpart of its property, or otherwise, all as though such payments had not beenmade.

5.                          Guarantoragrees that any and all present and future debts or obligations of any naturewhether arising in connection herewith or otherwise of Owner to Guarantor aresubordinated to the claims of Contractor with respect to the Agreement. Guarantoragrees to be bound by any findings of fact or final award or judgment (renderedunder arbitration or otherwise) made against Owner under the Agreement, or anysettlement reached by Contractor and Owner.

6.                          Theobligations of Guarantor set forth herein constitute the full recourseobligations of Guarantor enforceable against it to the full extent of all itsassets and properties.

7.                          ThisParent Guaranty shall be binding upon Guarantor and its successors and assigns.

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8.                          ThisParent Guaranty shall be governed by, and construed and interpreted inaccordance with the law of the State of New York. Venue for any action toenforce this Parent Guaranty shall be in a court of competent jurisdiction inNew York. Both parties to this Parent Guaranty waive all rights to a trial byjury in any action arising out of or relating to the Parent Guaranty.

9.                          ThisParent Guaranty and the terms, covenants and conditions hereof shall be bindingupon Guarantor and its successors and shall inure to the benefit of Contractorand its successors and assigns. Guarantor shall not be permitted to assign ortransfer any of its rights or obligations under this Parent Guaranty, exceptpursuant to a merger or consolidation in which (i) Guarantor is the survivor,or (ii) the surviving entity, if not Guarantor, is organized under the laws ofthe United States or a state thereof and explicitly assumes all obligations ofGuarantor under this Parent Guaranty.

10.                    Notwithstandingany other provision of this Parent Guaranty, Guarantor’s undertakings andobligations hereunder with respect to the Agreement are derivative of and notin excess of the Owner’s obligations under the Agreement and the Guarantorretains all rights, claims, defenses, and limitations of liability possessed byOwner under the terms of the Agreement or arising from the parties’ performanceor failure to perform thereunder and shall be entitled to assert anycontractual defenses that would have been available to the Owner under theAgreement, except that no defense previously raised by Owner which has beenfully adjudicated, determined or settled in accordance with the terms of theAgreement may be raised by Guarantor, and no cure period previously used byOwner may be used or relied upon by Guarantor.

**INWITNESS WHEREOF,**Guarantor has caused this Parent Guaranty tobe signed in the name and on behalf of Guarantor by its authorizedrepresentative as of this      day of                 2007.

 
|        |   |   | **Aventine Renewable Energy Holdings. Inc.** |
|--------|--------|--------|----------------------------------------------|
|   |   |   | ** **                                   |
|   |   |   | ** **                                   |
|   |   |   | By:                                          | /s/ Ronald H. Miller |
|   |   |   |                                         |   |
|   |   |   | Name:                                        | Ronald H. Miller |
|   |   |   |                                         |   |
|   |   |   | Title:                                       | President & CEO |

 

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