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                                                                EXHIBIT 10.18

                  AMENDMENT NO. 4 TO BUSINESS LOAN AGREEMENT
                                       
     This Amendment No. 4 (the "Amendment") dated as of April 23, 1997, is
between Bank of America NT & SA (the "Bank") and Portland Brewing Company (the
"Borrower").

                                   RECITALS
                                       
     A.   The Bank and the Borrower entered into a certain Business Loan
Agreement dated as of December 15, 1995, as previously amended (the
"Agreement").

     B.   The Bank and the Borrower desire to further amend the Agreement.

                                   AGREEMENT
                                       
     1.   DEFINITIONS.  Capitalized terms used but not defined in this
Amendment shall have the meaning given to them in the Agreement.

     2.   AMENDMENTS.  The Agreement is hereby amended as follows:

          2.1  In Paragraph 1.4 of the Agreement the date "May 1, 1998" is
substituted for the date "May 1, 1997."

          2.2  In Paragraph 1.5 of the Agreement, "Reference Rate plus .50
percentage point" is substituted for "Reference Rate."

          2.3  In Paragraph 1.8 of the Agreement "2.50 percentage points" is
substituted for "2.00 percentage points."

          2.4  Paragraph 2.5(a) of the Agreement is amended to read in its
entirety as follows:

               2.5(a)  The Borrower will pay interest on January 1, 1996, and
                       then on the first Banking Day of each month thereafter
                       until payment in full of any principal outstanding under
                       this line of credit.
                    
          2.5  Paragraph 2.5(b) of the Agreement is amended to read in its
entirety as follows:

               2.5(b)  The Borrower will repay the principal amount
                       outstanding on the Expiration Date in 84 successive equal
                       monthly installments starting June 2, 1997, and then on
                       the first Banking Day of each month thereafter. On May 1,
                       2004, the Borrower will repay the remaining principal
                       balance plus any interest then due.  The Borrower will
                       repay the principal amount outstanding under the
                       leasehold improvement with-in line on the Expiration Date
                       in 48 successive equal monthly installments starting
                       June 2, 1997, and then on the first Banking Day of each
                       month thereafter.  On May 1, 2001, the Borrower will
                       repay the remaining principal balance of the leasehold
                       improvement with-in line plus any interest then due.

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          2.6  Paragraph 2.7 of the Agreement is amended to read in its 
entirety as follows:

               2.7  LIBOR RATE.  The Borrower may elect to have all or portions
                    of the principal balance of the line of credit during the
                    term repayment period bear interest at the LIBOR Rate plus
                    2.50 percentage points.
                    
               Designation of a LIBOR Rate portion is subject to the following
requirements:

               (a)  The interest period during which the LIBOR Rate will be in
                    effect will be one, two or three months.  Each LIBOR Rate
                    will run from the first Banking Day of one month to the
                    first Banking Day of a subsequent month.
                    
               (b)  Each LIBOR Rate portion will be an amount not less than
                    Five Hundred Thousand Dollars ($500,000).
                    
               (c)  The Borrower shall irrevocably request a LIBOR Rate portion
                    no later than 9:00 a.m. San Francisco time three (3)
                    banking days before the commencement of the interest
                    period.
                    
               (d)  The "LIBOR Rate" means the interest rate determined by the
                    following formula, rounded upward to the nearest 1/100 of
                    one percent.  (All amounts in the calculation will be
                    determined by the Bank as of the first day of the interest
                    period.)
                    
                    LIBOR Rate =           London Rate
                                   ---------------------------
                                   (1.00 - Reserve Percentage)
                                 
                    Where,

                    (i)  "London Rate" means the interest rate (rounded upward
                         to the nearest 1/16th of one percent) at which the
                         Bank of America NT & SA's London Branch, London, Great
                         Britain, would offer U.S. dollar deposits for the
                         applicable interest period to other major banks in the
                         London inter-bank market at approximately 11:00 a.m.
                         London time two (2) London banking days before the
                         commencement of the interest period.
                         
                    (ii) "Reserve Percentage" means the total of the maximum
                         reserve percentages for determining the reserves to be
                         maintained by the member banks of the Federal Reserve
                         System for Eurocurrency Liabilities, as defined in the
                         Federal Reserve Board Regulation D, rounded upward to
                         the nearest 1/100 of one percent.  The percentage will
                         be expressed as a decimal, and will include, but not
                         be limited to, marginal, emergency, supplemental,
                         special, and other reserve percentages.
                         
               (e)  The Borrower may not elect a LIBOR Rate with respect to any
                    portion of the appreciable balance of the line of credit
                    which is scheduled to be repaid before the last day of the
                    applicable interest period.
                    
               (f)  Any portion of the principal balance of the line of credit
                    already bearing interest at the LIBOR Rate will not be
                    convened to a different rate during its interest period.

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               (g)  Each prepayment of a LIBOR Rate portion, whether voluntary,
                    by reason of acceleration or otherwise, will be accompanied
                    by the amount of accrued interest on the amount prepaid,
                    and a prepayment fee equal to the amount (if any) by which:
                    
                    (i)  the additional interest which would have been payable
                         on the amount prepaid had it not been paid until the
                         last day of the interest period, exceeds
                         
                    (ii) the interest which would have been recoverable by the
                         Bank by placing the amount prepaid on deposit in the
                         London inter-bank market for a period starting on the
                         date on which it was prepaid and ending on the last
                         day of the interest period for such portion.
                         
               (h)  The Bank will have no obligation to accept an election for
                    LIBOR Rate portion if any of the following described events
                    has occurred and is continuing:
                    
                    (i)  Dollar deposits in the principal amount, and for
                         periods equal to the interest period, of a LIBOR Rate
                         portion are not available in the London inter-bank
                         market; or
                         
                    (ii) the LIBOR Rate does not accurately reflect the cost of
                         a LIBOR Rate portion.
                         
          2.7  Paragraph 4.1 of the Agreement is amended to read in its
entirety as follows:

               4.1  FACILITY 1 LOAN FEES.  The Borrower agrees to pay a Two
                    Thousand Five Hundred Dollar ($2,500) fee on Facility No.
                    1, due upon the execution of the Loan Agreement.
                    
          2.8  Paragraph 6.5 of the Agreement is amended to read in its
entirety as follows:

               6.5  BANKING DAYS.  Unless otherwise provided in this Agreement,
                    a banking day is a day other than a Saturday or a Sunday on
                    which the Bank is open for business in Oregon and banks are
                    open for business in California.  For amounts bearing
                    interest at an offshore rate (if any), a banking day is a
                    day other than a Saturday or a Sunday on which the Bank is
                    open for business in Oregon, London, Great Britain and BofA
                    California is dealing in offshore dollars.  All payments
                    and disbursements which would be due on a day which is not
                    a banking day will be due on the next banking day.  All
                    payments received on a day which is not a banking day will
                    be applied to the credit on the next banking day.
                    
          2.9  Paragraph 9.2(a) of the Agreement is amended to read in its
entirety as follows:

               9.2(a)    Within 120 days of the Borrower's fiscal year end, the
                         Borrower's annual financial statements and 10-K Annual
                         Report. These financial statements must be audited by a
                         Certified Public Accountant ("CPA") acceptable to the
                         Bank.

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2.10 Subparagraph 9.2(h) is added to the Agreement to read
as follows:

               9.2(h)    Copies of the Borrower's Form l0-Q Quarterly Report
                    within 45 days after the date of filing with the Securities
                    and Exchange Commission.
                    
     3.   EFFECT OF AMENDMENT.  Except as provided in this Amendment, all of
the terms and conditions of the Agreement shall remain in full force and
effect.

     This Amendment is executed as of the date stated at the beginning of this
Amendment.

BANK OF AMERICA NT & SA            PORTLAND BREWING COMPANY


x Ed Kluss                         x Glenmore James
------------------------           -----------------------------
By:  Ed Kluss                      By:  Glenmore James
Title: Vice President              Title:    CFO


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