Question regarding RecipeDB Volume/Efficiency numbers

[Ionos]

Hoping someone can help with a simple question.

I've done about 10 all grain brews now using BIAB, following recipes in the RecipeDB. I'm consistently getting about 0.05 - 0.07 points lower in OG then that specified in the recipe, for the given volume. My efficiency however is consistently coming out the same or higher then listed when using an efficiency calculator - http://www.brewersfriend.com/brewhouse-efficiency/

Is the volume listed meant to be post-boil (i.e. pre trub losses) or final volume into the FV? I've been working on FV volume, however if it's actually post-boil volume that would explain the mismatch between the specified OG/efficiency and what I'm achieving.

Here's an example. I recently did this one - http://aussiehomebrewer.com/recipe/1385-session-stout/

• I assumed 23l into the FV, therefore ~25L post boil. I achieved 1.052 (vs. 1.057 listed).
• I calculated my efficiency for 25L @ 1.052 to be 77%. The recipe however specifies 75% to achieve 1.057.
• The only way I can see this is being possible is if the 23L figure is the post boil volume, so ~21l into the FV, which would then give 1.057 @ ~78% efficiency

Is that right?

 

[DJ_L3ThAL]

Everyones losses will be different, so I'd just go by the third dot point you have there as you've solved your own problem. Simply account for your 2L losses in the kettle and adjust your recipe accordingly, then you will hit the recipe numbers.