If you're uploading a recipe from another recipe creator system such as Brewer's Friend, Brewsmith or Brewfather via Beer.xml upload and you're noticing discrepancies and the numbers being out such as efficiency, this could be because - 

1. the app imports the ingredients used as new ingredients, however, beer XML is limited in the information it can provide. so users need to check each ingredients parameters to ensure they match. 
2. some other recipe creators use brewhouse efficiency then calculate mash efficiency whereas Grainfater uses mash efficiency and the equipment profile to calculate brewhouse efficiency. therefore you will need to match the efficiency in the grandfather app to the mash efficiency in the other creators
3. Here at Grainfather we don't know what formulas other recipe creators use and the resources they used to get to them.

For more information on the formulas and sources we use for our calculations please see the links below:

• ABV Calculation
• EBC Calculation
• IBU Calculation
• Gravity (OG and FG) Calculation
• Mash and Sparge Water Calculation