This entered in Cell B1 of your summary sheet

=SUM(

IF(ISNA(LOOKUP($A1,Sheet1!A:A)),"0",VLOOKUP($A1,Sheet1!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet2!A:A)),"0",VLOOKUP($A1,Sheet2!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet3!A:A)),"0",VLOOKUP($A1,Sheet3!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet4!A:A)),"0",VLOOKUP($A1,Sheet4!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet5!A:A)),"0",VLOOKUP($A1,Sheet5!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet6!A:A)),"0",VLOOKUP($A1,Sheet6!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet7!A:A)),"0",VLOOKUP($A1,Sheet7!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet8!A:A)),"0",VLOOKUP($A1,Sheet8!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet9!A:A)),"0",VLOOKUP($A1,Sheet9!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet10!A:A)),"0",VLOOKUP($A1,Sheet10!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet11!A:A)),"0",VLOOKUP($A1,Sheet11!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet12!A:A)),"0",VLOOKUP($A1,Sheet12!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet13!A:A)),"0",VLOOKUP($A1,Sheet13!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet14!A:A)),"0",VLOOKUP($A1,Sheet14!A:B,2,0)),

IF(ISNA(LOOKUP($A1,Sheet15!A:A)),"0",VLOOKUP($A1,Sheet15!A:B,2,0)))

will work for your needs, providing that your sheets are named Sheet1, Sheet2, Sheet3 and so on.

And your ingredients are listed from cell A1 down on each sheet and the numeric values are in cell B1 down on each sheet.

Hope this helps you out.

Coops