MS Access database engine does like to use aliases:
SELECT t1.IngredientLotId1, t1.IngredientName, t1.ActualWeight, t1.TargetWeight, (t1.ActualWeight- t1.TargetWeight )AS VARIANCE, (0.04* t1.TargetWeight )AS TOLERANCE , t2.StartTime, t2.EndTime
FROM CompletedIngredients As t1 INNER JOIN CompletedFormulas As t2 ON t1.RecordNumber=t2.RecordNumber
Change the code to your needs.