## Welcome to Northern Brewer

– "Brew, Share, Enjoy."

## pre boil efficiency calculator?

Moderator: Global Moderators

Master Brewer

Posts: 531

Joined: Sun Oct 22, 2006 10:17 am

### pre boil efficiency calculator?

I am currently in the middle of my boil, and would like to calculate my efficiency using my pre boil gravity reading. is there a calculator out there that I can enter my pre boil gravity and volume, then put in my projected post boil volume, and figure out efficiency.

Thanks

Master Brewer

Posts: 10107

Joined: Thu Sep 13, 2007 9:21 pm

Location: South Austin, Texas

You canâ€™t calculate efficiency from pre- and post-boil gravities and volumes alone. You need total potential gravity from the extract, sugars, and grains, and either the pre-boil or the post-boil gravity along with the relevant volume.

Master Brewer

Posts: 531

Joined: Sun Oct 22, 2006 10:17 am

I do, of course have my grain bill and what not. I did after all, make the beer

Master Brewer

Posts: 10107

Joined: Thu Sep 13, 2007 9:21 pm

Location: South Austin, Texas

Sorry, wasn't clear from your OP.

If you know the recipe, then you can use any of the on-line calculators, such as The Recipator: http://hbd.org/cgi-bin/recipator/recipator

Master Brewer

Posts: 1056

Joined: Sun Apr 09, 2006 7:54 pm

Location: Lansing, MI

if you're using software to calculate your efficiency, just up the batch size to your pre-boil volume and play with the efficiency number until you hit your measured pre-boil gravity.

Master Brewer

Posts: 1311

Joined: Thu Apr 12, 2007 4:19 pm

Location: St Paul, MN

It's just the same formula. gravity units (volume of wort x actual OG) divided by amount of grain x gravity potential

So 10# of base malt yielding 5 gallons of 1.050 wort would be
5 x 50 / 10 x 36 = 69.4% efficiency

Master Brewer

Posts: 238

Joined: Sun Oct 14, 2007 6:31 pm

Location: Hagerstown, MD

On deck: Kolsch
Primary: Denny's BVIP, Denny's Waldo Lake Amber
Cold Conditioning: Ian's Irish Red, Denny's Rye IPA, Beerfan's SNPA Clone, Dusseldorf Altbier
Keg: Ordinary Bitter, Beerfan's SNPA clone

Master Brewer

Posts: 1457

Joined: Tue Apr 01, 2008 8:42 am

Location: SODZ, Oh

He has a general equation for efficiency and a specific one based on the types of grain.

http://www.howtobrew.com/section2/chapter12-5.html
Drinking: Barley wine, Duvel Clone (2nd round 2011 NHC), Belgian Blond, Robust Porter (2nd round 2011 NHC), Tripel, Special Bitter (2nd round 2011 NHC), Oktoberfest (2nd round 2011 NHC), Saison

Lagering: Paulaner Oktoberfest Clone