Stovetop AG, OG and Beersmith - Help

Hi all,
I would like to try Deathbrewer's stovetop AG technique, but have some questions regarding figuring the recipe in Beersmith. I am going for a basic Irish stout.

Below is my recipe... Basically, after mash/sparge, I want to have a pre-boil volume of 4.5 gallons, down to just under 4 gallons post-boil and topping off to 5.5 gallons in primary.

Here are my questions:
1 - Does Beersmith calculate the topoff automatically? So, is the Target SG of 1.045 in the recipe accurate or will the dilution of the topoff reduce the SG?
2 - To determine my mash efficiency, when do I measure the SG? Do I measure a sample after my combined mash and sparge to reach my pre-boil volume of 4.5 gallons?
3 - Any recipe advice would be appreciated too!


Dry Stout
Type: All Grain Date: 2/13/2012
Batch Size (fermenter): 5.50 gal Brewer: Gavin
Boil Size: 4.50 gal Asst Brewer:
Boil Time: 60 min Equipment: Pot (6 Gal) - Extract
Final Bottling Volume: 5.10 gal Brewhouse Efficiency: 70.00
Fermentation: Ale, Two Stage Taste Rating(out of 50): 30.0
Taste Notes:
Prepare for Brewing



Clean and Prepare Brewing Equipment
Total Water Needed: 7.75 gal

Mash or Steep Grains

Mash Ingredients
Amt Name Type # %/IBU
6 lbs 8.0 oz Pale Malt (2 Row) US (2.0 SRM) Grain 1 62.5 %
2 lbs 4.0 oz Barley, Flaked (1.7 SRM) Grain 2 21.6 %
1 lbs 8.0 oz Roasted Barley (300.0 SRM) Grain 3 14.4 %
2.4 oz Acid Malt (3.0 SRM) Grain 4 1.4 %

Mash Steps
Name Description Step Temperature Step Time
Mash In Add 13.00 qt of water at 163.7 F 152.0 F 60 min

Batch sparge with 3 steps (Drain mash tun, , 1.25gal, 1.25gal) of 168.0 F water

Boil Wort

Add water to achieve boil volume of 4.50 gal
Estimated pre-boil gravity is 1.055 SG
Boil Ingredients
Amt Name Type # %/IBU
2.00 oz Goldings, East Kent [5.00 %] - Boil 60.0 min Hop 5 33.0 IBUs
0.30 oz Hallertauer [4.80 %] - Boil 60.0 min Hop 6 4.8 IBUs
0.50 tsp Irish Moss (Boil 15.0 mins) Fining 7 -


Estimated Post Boil Vol: 4.00 gal and Est Post Boil Gravity: 1.045 SG
Cool and Prepare Fermentation

Cool wort to fermentation temperature
Transfer wort to fermenter
Add water to achieve final volume of 5.50 gal
Fermentation Ingredients
Amt Name Type # %/IBU
1.0 pkg Irish Ale (Wyeast Labs #1084) [124.21 ml] Yeast 8 -

Measure Actual Original Gravity _______ (Target: 1.045 SG)
Measure Actual Batch Volume _______ (Target: 5.50 gal)

 

Im about to fall asleep but key me ask, do you have an iPhone? If so check out the app Brew Pal; its much easier to use and understand, especially for beginners.

 

No iAnything unfortunately.

 

BeerSmith does caculate water volumes automatically, but the default #s are just generic, and could be way off for your pot.

To get the numbers to be more accurate, you really need to measure your pot's boiloff rate and plug that number into a custom equipment profile in BeerSmith. You also have to remember that things like grain absorbsion and loss to trub are different brew to brew, so you can plug in average numbers, but it is always going to differ depending on the recipe.

You could just topoff to 5.5 gallons, but if your efficiency is lower than the recipe's 70% assumption, then you may water down your beer.

The only way to get it SPOT on is to measure the OG with a hydrometer post-cooldown, then add water to meet the recipe OG, NOT to try to hit a particular volume. So, your recipe calls for 1.055 OG, and your measured OG is 1.07, you would add water (mixing well) until you got to 1.055 on the hydrometer, NOT to a specified water volume. If you hit all your numbers, then it would be 5.5 gallons, but with this method no matter what your efficiency, you'll still nail the recipe, even if you don't yeild 5.5 gallons.

Does that make sense?

 

Thanks Topher... I think that makes sense, but let me confirm... I have tweaked this a bit more. Here are the new numbers:

After sparge, I expect my pre-boil volume to be 4.5 gallons (est. SG of 1.060). My pot will lose about 1 gallon of this during the 60 minute boil, so my post-boil pre-topoff volume is 3.5 gallons.

Now here is the question I am still fuzzy on. In Beersmith, it lists an est. post-boil SG of 1.049. Would this SG be as measured from my 3.5 gallons of post-boil wort or on my 5.5 gallon full batch size after top off? FYI... I understand your point regarding adding H2O until I reach the right SG. I am just trying to make sure I understand the est. post-boil SG as provided by Beersmith.

THANKS FOR YOUR HELP!!!!!

 

If you measure your POST BOIL gravity at 3.5 gallons as 1.060 (or whatever the # is), and your EXPECTED gravity for the recipe is 1.049 per BeerSmith, you would top off with enough water to dillute the beer to the 1.049 gravity. That amount of water is probably going to be less than the expected 2.0 gallons, just because everything never goes 100% perfect.

Forget about the 5.5 gallon target volume, worry about hitting the target gravity, even if that leaves you with less than 5.5 gallons. The gravity (percentage of sugars in the wort) is the most important part to creating the intended recipe.

 

Thanks Topher... Makes sense. As I have been playing around in Beersmith with the Boil Off and Dilution Tools, it also has become really clear how the estimated gravity readings are changing throughout the brewing process.