Home of the BrewNosers

Shouldn't your recipes OG change with the length of boil? The reason I ask is I am doing up a recipe, and want an OG of 1.082. I've got that far, but my default setting for boil length is 60 min but i'm supposed to be doing a 90 min boil...so I go ahead and change it to a 90 min boil, except my grain bill doesn't change, nor does my OG.

Jimmy,

I'm not sure if Brewsmith will work the same, but I know how Homebrew Formulator would handle this. The OG would be the same no matter the length of the boil. What would change is the amount of sparge volume water that was calculated, it would be greater with a 90 minute boil than for a 60 minute boil, by 1/2 of your evaporation rate (gal/hr).

The most relevant settings are 1) In your brewing environment, the target volume coming out of the boil (for me it is 5 gal. or 19 liters); and 2) How many fermentables are in the recipe. Using these two things only, one should be able to calculate the OG of the batch. How many fermentables per what volume is all that is going to determine the specific gravity of that liquid.

Hopes this makes at least a little sense???

JLC

Seems that number is just for info. Batch size and efficiency change the og on the main page. You can go into boil-off for calculating boil length effects.

I think I understand. I'm extracting the same amount of fermentables from the mash regardless of boil time, so when I adjust from a 60-90 min boil my sparge water increases to compensate for the extra wort being boiled off, leaving me with the same volume & OG as a 60 min boil.

I just think that the number for boil time on the front page is not a part of any calculation. It's just a record, and you have to do the calculations on the boil-off tab.