Screwed up my boil off or something?

[forgetaboudit]

So today I brewed my first BIAB. I boiled 5 gallons of water for 15 minutes and covered with a lid until room temp. I measured the remainder and calculated the loss x 4 to equal 60 minutes. It came out to be aboit 1.5g/hr.
So I used Beer Smith to figure pre-mash water volume and got 8.65 g. I mashed, and ended up 2 points shy of my target gravity post-mash.
I finished the boil and realized i had more wort than my expected 5g...
I checked the gravity and it was the same as post-mash, but had 6 gallons...
If I started with less water, my post mash gravity would've been too high right?
Im so lost as to what happened, and what to do to not have it happen again...

 

[jtratcliff]

So now you have a new data point for your boil-off rate.... What boil off rate do you get from this?
What did you assume for grain absorption? BIAB values can vary for squeezers vs. non squeezers...
And it's usually quite different from tradition mash tun values.... Any dead space or
false bottoms? Gotta factor it all in...

Since you're close to your OG with an extra gallon of wort, it means you might also need to re-evaluate your assumed efficiency...

Might be mis-measure of the boil-off, might be wrong assumption for absorption.
Dialing in your system is just part of the process...

Perfect excuse to brew more
Gotta nail down those numbers!

 

[RM-MN]

I finished the boil and realized i had more wort than my expected 5g...
I checked the gravity and it was the same as post-mash, but had 6 gallons...

Oh darn, your efficiency was higher than the recipe was written for an you ended up with more beer than expected. Please explain how this is a problem. Do you not have enough bottles to fit it all into? Does it overflow your keg? You could just dump out the excess.

 

[wilserbrewer]

With your results, you know that your grain amount and total water amounts were approx 1/6 too large.

Rather than calculating and predicting individual losses, I prefer to focus on total losses.

Total water vs beer out...I don’t really care where my losses occur, but rather what they are in total.

Reduce fermentables and total water in proportion to your actual results.

My ball park guess is you need to increase your value for efficiency by about 10% and your water losses by about a gallon.

Your post mash and post boil gravity being the same indicates an error in your gravity readings.

Try again, rdwhahb and better luck next time.

 

[Franktalk]

In BeerSmith, the batch size that you choose is what you hope to end up with in the end, when you package your beer. So, because you lose beer at every step from boil to bottle or keg, it will give you an extra half gallon at the end of the boil.

 

[deadwolfbones]

Also, it's impossible for your SG to be the same before and after a 60 minute boil. Something is up there, and I imagine it has to do with post-mash wort that wasn't stirred well enough before taking a sample.

 

[forgetaboudit]

So now you have a new data point for your boil-off rate.... What boil off rate do you get from this?
What did you assume for grain absorption? BIAB values can vary for squeezers vs. non squeezers...
And it's usually quite different from tradition mash tun values.... Any dead space or
false bottoms? Gotta factor it all in...

Since you're close to your OG with an extra gallon of wort, it means you might also need to re-evaluate your assumed efficiency...

Might be mis-measure of the boil-off, might be wrong assumption for absorption.
Dialing in your system is just part of the process...

Perfect excuse to brew more
Gotta nail down those numbers!

The boil off rate I figured before brew day was 1.5 gallons/hr.
Now, after my brew, I boiled 5 gallons of water for an hour and got 2 gallons of boil off... If I used that number, I would have 1.5 gallons too much wort instead of 1.
I used Beer Smith for all the calculations...

 

[forgetaboudit]

With your results, you know that your grain amount and total water amounts were approx 1/6 too large.

Rather than calculating and predicting individual losses, I prefer to focus on total losses.

Total water vs beer out...I don’t really care where my losses occur, but rather what they are in total.

Reduce fermentables and total water in proportion to your actual results.

My ball park guess is you need to increase your value for efficiency by about 10% and your water losses by about a gallon.

Your post mash and post boil gravity being the same indicates an error in your gravity readings.

Try again, rdwhahb and better luck next time.

I had efficency at 70% in Beer Smith, Ill bump it up to 80%.

 

[forgetaboudit]

Also, it's impossible for your SG to be the same before and after a 60 minute boil. Something is up there, and I imagine it has to do with post-mash wort that wasn't stirred well enough before taking a sample.

I dont think I stirred it before measuring post-mash... I figured pulling the bag out mixed it up enough. Ill be sure to stir well before measuring next time.

 

[jtratcliff]

The boil off rate I figured before brew day was 1.5 gallons/hr.
Now, after my brew, I boiled 5 gallons of water for an hour and got 2 gallons of boil off...

But what boil off rate did you get when you actually boiled your wort?

You added 8.65G of water to ?? lbs of grain.... You lost some liquid to grain absorption... How much? Beer Smith assumes some amount of loss to the grain. That assumption can be off depending on whether you squeeze or not, how much you squeeze, etc.

What was the volume of wort you started with after pulled your bag, before the boil? If you know how much wort you had before you started the boil, you have another data point for boil off rate for your system... And a data point for grain absorption for your system/process.

Nailing down the numbers for your system is all part of it... The software can only give you good answers if it has good inputs... Quite often the default assumed values are not quite right for a given system. You need to measure for your system and adjust the values. Once you get your equipment profile dialed in, you'll have better luck hitting all your numbers.

It can take a few brew sessions to get it all just the way you want it. All you can do is take lots measurements along the way and keep good notes.

 

[CascadesBrewer]

In BeerSmith, the batch size that you choose is what you hope to end up with in the end, when you package your beer.

Actually, with BeerSmith the "Batch Volume" is the amount that goes into the fermenter. There is a separate "Bottling Volume" value that is calculated.

I had efficiency at 70% in Beer Smith, Ill bump it up to 80%.

80% is definitely possible with BIAB and fine crushed grain and limited volume losses.

For me, on my propane burner with a rolling boil I get about 1 gal per hour boil off. If I crank up my burner I can get up to 1.5 gal per hour (but that seems like a waste of propane to me). Volumes will vary some based on grain bill and amount of hops, but will be something like:

• 7.5 gal mash water
• 6.75 gal pre-boil
• 5.75 gal post-boil
• 5.5 gal into fermenter (my Batch Volume)
• 5.0 gal into keg

So for tuning BeerSmith, you need to tweak Grain Absorption, Boil off Rate, and Losses at each stage (BeerSmith also calcs the volume shrinkage due to temperature change). You then tweak your "Efficiency" to match your results.

 

[forgetaboudit]

But what boil off rate did you get when you actually boiled your wort?

You added 8.65G of water to ?? lbs of grain.... You lost some liquid to grain absorption... How much? Beer Smith assumes some amount of loss to the grain. That assumption can be off depending on whether you squeeze or not, how much you squeeze, etc.

What was the volume of wort you started with after pulled your bag, before the boil? If you know how much wort you had before you started the boil, you have another data point for boil off rate for your system... And a data point for grain absorption for your system/process.

Nailing down the numbers for your system is all part of it... The software can only give you good answers if it has good inputs... Quite often the default assumed values are not quite right for a given system. You need to measure for your system and adjust the values. Once you get your equipment profile dialed in, you'll have better luck hitting all your numbers.

It can take a few brew sessions to get it all just the way you want it. All you can do is take lots measurements along the way and keep good notes.

I had 15 lbs of grain, 8.65 gallons of water pre mash, I'm not too sure the volume I had post mash, but ended up with 6 in the fermenter.
I drained the bag for 20 minutes, and squeezed it as well. I then added that wort to the boil.