Estimated Original Gravity

[gethrog]

Just on my 3rd brew and I'm still having some difficulty with mash eficiency and volumes. I have Beersmith which has helped me out of a few fixes, and Screwtop and Bindy have been great too. Anyway, a question. In Beersmith is the Estimated original gravity, the gravity of the wort before or after the boil? If its after, and say I am looking for a SG of 1047, what should be the rough SG, preboil.

 

[Trent]

Just on my 3rd brew and I'm still having some difficulty with mash eficiency and volumes. I have Beersmith which has helped me out of a few fixes, and Screwtop and Bindy have been great too. Anyway, a question. In Beersmith is the Estimated original gravity, the gravity of the wort before or after the boil? If its after, and say I am looking for a SG of 1047, what should be the rough SG, preboil.

If your postboil OG is 1047 in 23L, then your preboil should be that, divided by your prebil volume, say 30L.
47 * 23 =1081/30 = 36. So your preboil should be 1036.
HTH
Trent

 

[melbrine]

Just on my 3rd brew and I'm still having some difficulty with mash eficiency and volumes. I have Beersmith which has helped me out of a few fixes, and Screwtop and Bindy have been great too. Anyway, a question. In Beersmith is the Estimated original gravity, the gravity of the wort before or after the boil? If its after, and say I am looking for a SG of 1047, what should be the rough SG, preboil.

I don't use Beersmith, but it works this way.
Volume at beginning of boil X Gravity at beginning of boil = Volume at end of boil X Gravity at end of boil
(Make sure you stir the wort before taking preboil SG so that you are not just taking from the bottom or top, depending how you get your sample into the hydrometer)
So, (High school maths here) Gravity at end of boil = Volume at beginning of boil X Gravity at beginning of boil divided by Volume at end of boil.
As the volume reduces during the boil, the gravity increases. You need to know the evaporation of your system but you can then adjust preboil and get pretty close to the gravity you want.
Hope this helps - it works for me.

 

[t2000kw]

Just on my 3rd brew and I'm still having some difficulty with mash eficiency and volumes. I have Beersmith which has helped me out of a few fixes, and Screwtop and Bindy have been great too. Anyway, a question. In Beersmith is the Estimated original gravity, the gravity of the wort before or after the boil? If its after, and say I am looking for a SG of 1047, what should be the rough SG, preboil.

OK, I give up. What is Screwtop and Bindy? Are these other brewing programs? Or is this an Aussie pun of sorts?

 

[cozmocracker]

OK, I give up. What is Screwtop and Bindy? Are these other brewing programs? Or is this an Aussie pun of sorts?

lol, members of AHB.

 

[gethrog]

OK, I give up. What is Screwtop and Bindy? Are these other brewing programs? Or is this an Aussie pun of sorts?

Thanks for the assist. Just to put your mind at ease Screwtop and Bindy are two members of this forum. They know beer making inside out and have been a great help to a newbie like me.

I ened up working the SG on the last brew by "guestimation" but your easy formulae will be used in future. Beersmith might do it but I haven't worked with it too often to know.

 

[t2000kw]

Thanks for the assist. Just to put your mind at ease Screwtop and Bindy are two members of this forum. They know beer making inside out and have been a great help to a newbie like me.

Thanks!!!

I figured that out just before reading your reply by checking my PMs here. One was from Screwtop about a spreadsheet he had, so I figured that these were other members here. But thanks for the answer.

 

[Sammus]

In beersmith the estimated OG is the OG post boil. To know the preboil gravity click the brewhouse efficiency button or the preview brewsheet button, both have estimated preboil vol and grav.

If your preboil gravity/volume is out you may need to adjust things. If you follow the beersmith calcs your volume should be pretty close to spot on. So if your gravity is out adjust your efficiency.

If your preboil grav/volume is on target but postboil things are working properly, you may need to tweak the boil off setting. Mine works well at about 15%.

Another thing to consider - on setting up your equipment specs, you should leave the 'loss to boil trub and chiller' set to zero, and add whatever the loss might be to your final batch size. Beersmith has this bug that they refuse to fix for some reason, where they assume any loss to lines and chiller and trub etc is pure water, and all the sugars and hop compounds magically transfer to the bit that goes in your fermenter. Can seriously through your calcs out - I figured this out after 2 years of thinking I had bung efficiency...now I wish someone had told me. I'd seen people mention it regarding IBU calcs, but not about OG calcs... anywho, hope that helps.