Newb trying to understand Beersmith

[Mothman]

About to do my first extract brew (Ontario Beer Keg, English Brown Ale, 3 gal kit) this weekend, and just to play, I tried putting the recipe into Beersmith, mostly as a learning exercise.

I set up (I think) a very simple equipment profile...

8 gallon pot, full-volume boil, estimate of 1 gal/hr boil off, only loss I've included is 0.25gal in fermenter (figuring I'll dump everything from the kettle into the fermenter, and I have no idea what I will leave behind when I bottle, but I'm guessing)

Recipe info is pasted below. The kit ingredients and instructions are here: http://www.ontariobeerkegs.com/v/vspfiles/assets/images/3gal - english brown ale.pdf


OBK English Brown Ale - 3 Gal


Type: Extract
Batch Size: 3.25 gal
Boil Size: 3.89 gal
Boil Time: 30 min
End of Boil Vol: 3.39 gal
Final Bottling Vol: 3.00 gal
Fermentation: Ale, Single Stage
:


Grains to Steep

8.0 oz Brown Malt (65.0 SRM) Grain 1 10.0 %
8.0 oz Caramel/Crystal Malt -120L (120.0 SRM) Grain 2 10.0 %


Boil Ingredients

1 lbs Amber Dry Extract (12.5 SRM) Dry Extract 3 20.0 %
3 lbs Amber Liquid Extract (12.5 SRM) Extract 4 60.0 %
1.00 oz Fuggle [4.50 %] - Boil 30.0 min Hop 5 22.0 IBUs
1.00 oz Fuggle [4.50 %] - Boil 10.0 min Hop 6 10.4 IBUs


1.0 pkg SafAle English Ale (DCL/Fermentis #S-04) [23.66 ml] Yeast 7



My question is, for something seemingly quite simple, and extract based (so no question marks in terms of efficiency, etc), why do the IBU's and ABV not match between Beersmith and the OBK recipe?

OBK says 20 IBU, Beersmith says 32.

OBK says 5% alc, Beersmith says 4.6%

The color matches for both at 20 SRM.

I notice that the volumes are slightly different...(Beersmith = 3.89 pre-boil, 3.39 post, OBK = 3.75 pre-boil, 3.25 post) I think because Beersmith takes cooling shrinkage into account, while the OBK instructions do not.

But would that slight volume difference cause the significant change to IBU and ABV?

Either way, it's all good... just trying to understand.

 

[CA_Mouse]

First off, with almost any 'kit' beer, the size of the batch needs to match the kit. If the kit says 5 gallons, then you need to have 5 gallons in the fermenter, if it says 3 gallons, then you need 3 gallons in the fermenter. That said, when I was doing kits, I made sure that the final volume into my fermenter matched what the kit volume expected. I would boil 3 gallons for a 5 gallon batch and then top the fermenter to match the expected Starting Gravity. This will help control the variances in ABV.

Check which scale you are using in BeerSmith for Hop Utilization, there are 3 different scales and it defaults to Tinseth. It is possible that the kit creator(s) used one of the other scales. That will cause a difference between what you expect and what BeerSmith says. In honesty, most of us can't discern the difference between 20 IBU, 25 IBU and 30 IBU. Denny Conn and Drew Beechum had their IGORs test this out pretty extensively and even went as far as having the beers tested for actual IBUs. Check out the Experimental Brewing podcast and website, for more on this one!

 

[Oginme]

Since this is your first time using BeerSmith, don't sweat the relatively minor differences you see between the recipe and BeerSmith's predictions at this point. When you go to brew, measure you water volumes carefully and gravity readings pre- and post-boil to give you an idea of what your actual boil-off rate is. Then you can go back and make any adjustments you need in your profiles to make the BeerSmith prediction match your actual results.

For the IBU discrepancy, if the recipe does not tell you what IBU model it is using, then let it ride as the kit has given you to produce the brew. IBU calculations are pretty variable anyway as much of your actual results depends upon each individual's process. My recommendation is that when you get serious about building your own recipes then you will need to be aware of the difference between the IBU number and your actual perception of bitterness. This, IMO, is best done by brewing something similar to a beer you can get commercially that has a published IBU value and then comparing your result in bitterness perception with that of the commercial product. You can then gauge whether you should aim higher or lower in number to obtain the actual bitterness that you want.

For ABV, BeerSmith uses the average attenuation for the yeast selected and the assumed fermentability of the wort (in this case the extract). The recipe may use actual results obtained by the person who developed the recipe, the results from a different calculator, or some other estimation.

one thing that you didn't mention in typing in the recipe is the OG of the recipe versus what is printed in the recipe instructions. This is much more important to getting to the proper ABV and there are assumptions made in terms of the extraction from steeping grains which may affect this value.

 

[neverfadeaway86]

I use Brewers Friend Recipe calculator it seems easier and has worked well for me

 

[Mothman]

First off, with almost any 'kit' beer, the size of the batch needs to match the kit

So, this kit is listed as a 3 gallon kit, with 3.25 gallons post boil, before cooling. It doesn't say the volume in the fermenter after cooling.

Is the batch size 3 or 3.25 gallons?

 

[Mothman]

one thing that you didn't mention in typing in the recipe is the OG of the recipe versus what is printed in the recipe instructions. This is much more important to getting to the proper ABV and there are assumptions made in terms of the extraction from steeping grains which may affect this value.

If I recall correctly, both Beersmith and the original recipe match OG at 1.048.

 

[CA_Mouse]

So, this kit is listed as a 3 gallon kit, with 3.25 gallons post boil, before cooling. It doesn't say the volume in the fermenter after cooling.

Is the batch size 3 or 3.25 gallons?

Just a heads up... Hot wort takes up more volume than cool wort. After cooling 3.25 gallons to proper pitching temperature, you will have pretty close to 3.125 gallons in your kettle. Take into consideration losses due to trub and transfer hoses, you should be pretty much spot on at 3 gallons. :rockin:

 

[Mothman]

Just a heads up... Hot wort takes up more volume than cool wort. After cooling 3.25 gallons to proper pitching temperature, you will have pretty close to 3.125 gallons in your kettle. Take into consideration losses due to trub and transfer hoses, you should be pretty much spot on at 3 gallons. :rockin:

Right, I understand that. That's why the Beersmith volumes are different than the original recipe volumes, I assume. Beersmith allows for cooling shrinkage.

Still unsure whether "batch size" refers to volume into fermenter, or volume into bottles. As I understand it, those volumes aren't the same, due to the trub left behind in the fermenter.

 

[Oginme]

Right, I understand that. That's why the Beersmith volumes are different than the original recipe volumes, I assume. Beersmith allows for cooling shrinkage.

Still unsure whether "batch size" refers to volume into fermenter, or volume into bottles. As I understand it, those volumes aren't the same, due to the trub left behind in the fermenter.

In BeerSmith, Batch size is the volume INTO the fermenter.

 

[Mothman]

OK that makes sense.

 

[CA_Mouse]

In BeerSmith, Batch size is the volume INTO the fermenter.

I believe that is what I said! lol

 

[Mothman]

Yeah you did lol.

It just confused me in your first comment of your first post,advising me to set batch size in beersmith to match the kit... Because I believe I had already done that with 3.25 gallons.