When extract is added at end of boil, it changes pre-boil gravity.

I am making a recipe using a (biab) partial mash, where I add 3 pounds of DME at the end of the boil.

Adding the extract at 0 minutes of the boil, BS2 does 2 things wrong:
1. it places the DME before the 0 minute hop addition
2. it changes the pre-boil gravity to look as if you added the DME pre-boil, which is just wrong.

As far as I understand, the DME should be added at the end of the boil and not after it has cooled. If I check the "add after boil" box BS2 moves the DME to the next box below the yeast. Adding the DME then would be dangerous since there could be bacteria hiding out in the DME.

Right now I am just trying the trial version, (windows 8.1) but it says it is up to date. Pretty annoying problem.

Additionally, any time there is an extract in the recipe the "Measured Efficiency" box goes up way past 100% (it says 111% for my recipe).

I've attached the recipe with which I have encountered these problems. You can see the pre-boil gravity says 1.091, but it should say 1.058.

EDIT: To clarify, I am adding the extract at the end of the boil to get greater hop utilization, since I currently only have a 5 gallon pot. After it cools, I add (previously boiled and cooled) water to bring the volume up to 5.5 gallons in the fermenter.

EDIT 2: To further clarify, if the "Add after boil" box is checked on the dry extract, the efficiencies are as follows:

Measured efficiency: 127.7%
Measured Mash Eff: 72.8%

And if the "Add after boil" box is unchecked, they are:

Measured efficiency: 87.2%
Measured Mash Eff: 32.3%

So you have to switch back and forth to find out both numbers.

OFF TOPIC:

I imagine there must not be many partial-mash brewers using BS2 if I am the first person to have this problem. I myself have been using Brewer's Friend up till now, which works just fine but I want something a bit more powerful. I plan on going AG in a couple months so this may not continue to be a problem, but one thing I miss is the Brewing Sessions that Brewer's Friend has, which allows you to take a snapshot of your recipe at brewing time and then track your progress and numbers throughout the brewing session.

It seems with BS2 this would not be possible, that you just have to change the "measured" numbers for each time you brew a recipe, so it is not good for record keeping.

I do prefer a good windows program over web software. In fact, we have been having bit of a blizzard here in MI and last night when I was making this recipe I lost internet, and was not able to plug in my numbers to BF, but still had use of BS2. Have you thought at all about adding some sort of Brewing Session type functionality? If you did and fixed the bugs BS2 would be perfect in my eyes. (The trub/chiller loss is very confusing. Do you mean hop absorption?)

I've done a bit of dabbling in C++ (the most beautiful/powerful language!) and would love to help with this software if you need it and use C++, just to get some experience working on something real. I am extremely busy for the next month and a half but after that perhaps. If not, no biggie, just fix your bugs.

lokoroth said:

but one thing I miss is the Brewing Sessions that Brewer's Friend has, which allows you to take a snapshot of your recipe at brewing time and then track your progress and numbers throughout the brewing session.

Click to expand...

In BeerSmith, this feature is called the Brew Log. In the top ribbon, you copy the recipe to the Brew Log.

That folder will be created if you don't already have one and point to it in the Options menu.

You should then see it in the My Recipes view.

lokoroth said:

I've attached the recipe with which I have encountered these problems. You can see the pre-boil gravity says 1.091, but it should say 1.058.
...
The trub/chiller loss is very confusing. Do you mean hop absorption?

Click to expand...

BeerSmith tracks total volume and total fermentables to determine gravities.

Brad has said that BS needs a better way of handling kettle and post kettle sugars. So, this could be coming, but there is no guarantee of when. 

Trub/Chiller loss and the associated changes to efficiency confuses a lot of people. It's simply the amount of wort that doesn't get into the fermenter. Each time you add to it, you have to reduce your Brewhouse efficiency by the same percentage.

Brewhouse Efficiency is not as straightforward as mash efficiency, but when you have trub loss and you're using top off water, it's necessary for determining fermenter gravity.

Thank you Brewfun! The Brew Log is exactly what I needed and will serve my purposes.

I am curious about the data structures BS2 uses that would make the pre-boil gravity tied to the total amount of fermentables. It seems like it wouldn't be that hard to include some logic in the calculation to check whether the ingredient is fermentable and a later addition.

I have bumped into this problem brewing a belgian tripel with a late sugar addition. It seems to me that the pre-boil gravity is calculated from the post-boil gravity, instead of taking into account the actual mash/mash efficiency. I have just started all-grain brewing and this bug had me believing I had an awful mash efficiency Let's hope it gets fixed soon...

mikonapoli said:

It seems to me that the pre-boil gravity is calculated from the post-boil gravity, instead of taking into account the actual mash/mash efficiency.

Click to expand...

Why do you believe that?

In BeerSmith, mash efficiency is driven by your brewhouse efficiency number. The basis of the gravity numbers is your grist, since each contribution is calculated separately. Brewhouse efficiency can be a little hard to wrap your head around, especially if you've just gotten into all grain. It's measured post chill, in the fermenter.

If you're more comfortable with just mash efficiency, then make the loss to trub field "0" in your equipment profile. This makes the batch size equal to your postboil kettle volume (chilled, though). Don't just blindly follow the preset profiles, either. Make sure the numbers are correct for your specific setup. Volumes, gravity, cooling, boiloff. It all matters. The more accurate with your specifications, the more accurately BeerSmith predicts your outcomes.

It was just a guess based on the fact that, if everything else stays the same, a late boil addition of sugar (or extract) increases the estimated pre-boil gravity, while the same addition, "added after boil" does not.

I understand the concept of brewhouse efficiency, but having a correctly estimated pre-boil gravity gives me something to shoot for. Most importantly, having an idea of what's my mash efficiency gives me a tool for when I'm not around my computer.

mikonapoli said:

It was just a guess based on the fact that, if everything else stays the same, a late boil addition of sugar (or extract) increases the estimated pre-boil gravity, while the same addition, "added after boil" does not.

Click to expand...

I'm not able to replicate this behavior. As long as the amount stays consistent, so does the OG, regardless of when the addition happens.

The behavior I've described does cause confusion for brewers who add sugars to create secondary or tertiary fermentation. They don't get a true reading of their post boil gravity. However, since BeerSmith simply uses all sugar additions to create an abv% number, a single OG represents the sum of all additions.

I understand the concept of brewhouse efficiency, but having a correctly estimated pre-boil gravity gives me something to shoot for.

Click to expand...

Previously in this thread, Yours Truly answered that complaint. Perhaps unsatisfactorily, but truthfully:

brewfun said:

Brad has said that BS needs a better way of handling kettle and post kettle sugars. So, this could be coming, but there is no guarantee of when. 

Click to expand...

Thanks for the answer. I will make some more experiments as soon as I have some time and see if I can replicate them myself. Also: I had read your answer, but I had badly misread the date (I thought it was 2 years old!) sorry for pressing the issue.

I hope this one gets fixed soon.  Screwed up a brew last night.  We were trying to hit the pre-boil gravity BeerSmith said we should hit.  We were under the gravity 1/2 way through sparge.  Collected extra wort thinking we could boil it down and realized at the end of the night that BS add the brown sugar that went in with 15 minutes left in the boil to the pre-boil gravity. 

The only work around I see is to set your late addition sugar to "unfermentable"to calculate your pre-boil gravity, write it down and then change it back to fermentable (you could also take the amount down to zero and then add it back in).  If you try to hit pre-boil gravity from BeerSmith and you have sugars added during boil, you are in for a long night.