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OG Calculation

Stevedkiwi

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OK Here goes !!
I am new to brewing and have just done three kit brews so far.
but I have really caught the bug as I find the whole business fascinating.

Anyway I plan to continue with kits but get into proper extract and eventually probably partial mashes before too long.

So I figure a software tool is a good idea and like the look of Beer Smith.

However ...

I am the kind of guy that needs to know how stuff works and I cannot really get my head around a few key parts of brewing calcs. Hopefully someone can help me without baffling me with jargon.
I will frame my questions based on using Beer Smith., and will post each question (Or series of sub questions of questions) seperately.
Please bear in mind that we are metric down here at the bottom of the world (Or top depending on your outlook)

1. Adding beer kits to the grains table.

a) IBU / EBC

Our main local producers package in 1.7kg cans and quote IBU's and EBC's as packaged eg the Coopers APA is quoted as being 340 IBU and 90 EBC.
Coopers state that to get the actual IBU of the brew (Assuming no further hop additions) you multiply by the weight and divide by the batch size so
340 * 1.7kg / 23L = 25.1 IBU which is just at the bottom of the range for APA. (Our standard batch size here in NZ is 23 L)

I presume that to enter this kit in BS I would enter 40.4 IBU being the US imperial equivelent of 340 g/l and BS takes care of the rest
This results in an IBU of 23 in BS which is fairly close I suppose to the Coopers calc.

For EBC I am really confused though as i am not at all sure how the calcs work. Entering 90 as the EBC gives me a predicted EBU of over 28 is way too high.
what should I be entering ? should it be 10.7 whis is 90 / 8.4 (Metric to imperial again) ? this gets me close to the bottom of the style range so I guess its right.

b) Potential SG

How do i estimate the Potential SG for a kit? manufacturers dont sem to provide it and I have seen some widely varying numbers in various spreadsheets etc
Alos if I am simply adding the kit and enhancers to the fermenter (With a little boiled water plus top up with cold as per kit instrauctions) then should I set the yield at 100% ?

PS I have downloaded an add on which lists Coopers kits but they are  listed at the respective Can label IBU and EBC levels  and with an SG of 1.036

PPS The beer enhancer used in my brew is Coopers enhancer no 2 which is 250g Light Dry malt, 250g Maltodextrose, 500g Dextrose(Corn Sugar)

thanks to anyone who can help me out here. I really want to understand the basics rather than just presuming that the numbers are right.

thanks Steve D
 
Steve

I'll attempt to answer the Starting Gravity question.
If you are Extract Brewing the program will automatically give you 100% efficiency on the "sugars" added.
Every type of malt has a potential sugar content and is expressed in a number that looks like a Specific Gravity reading. 
Dry Malt Extract (DME) typically has a potential gravity of 1.036 and Liquid Malt Extract (LME) has a potential gravity of 1.044

This means that one pound of DME disolved in one gallon of water will result in a Specific Gravity of 1.036.
The easier way to manually work the numbers (at least in US units) is to think in terms of Gravity Points Per Pound per Gallon (PPG)
Start with the potential gravity number 1.036 and drop all of the numbers except the last two 1.036 = 36 PPG

To "design" your brew you start with the Original Gravity; let's assume we want 5 gallons of 1.050 specific gravity wort in the fermenter
The total sugar is then 5 gallons x 50 PPG  =  250 total sugar points.
If I am using DME at 1.036 or 36 PPG, I will need  about 7 pounds of DME (250 / 36  =  6.94 lb)
If I am using LME at 1.044 or 44 PPG, I will need  about 5.7 pounds of DME (250 / 44  =  6.94 lb)

The next step backwards is the pre boil gravity check.  Lets assume I will boil off 1 gallon; so I will have a total of 6 gallons per boil.
I have "designed" my recipe to be 1.050 at 5 gallons, so I have 250 total sugar points.  If that sugar is in 6 gallons my specific gravity will be 250point / 6 gallons  =  42 points or 1.042 specific gravity.

Grains work the same way, but now there are sugar conversion and extraction losses that need to be accounted.

I haven't been able to wrap my head the same calculations with metric units yet,  but it should work the same.

Good luck and welcome, David
 
Thanks David,

Yeah I get the calcs now but still got a much lower OG in BS than actual on brew day, and less than calculated on some other calc sheets.

First issue was what is the Potential of a beer kit. After more investigation it seems that 1.036 is standard which makes sense as its just LME with a few hops.

So I looked at each other ingredients comparing the BS and other software and found that they had similar potentials for the DME (1.044) but different for Dextrose (1.046 in BS, 1.041 in the other ). Where the big difference is though, is that maltodextrine (Sorry I said maltodextrose in my original post) is listed as a "Misc" in beer smith so doesnt come into OG or FG calcs.

It actualy has a potential of 1.042 and is listed as a sugar in the other software and so contributes to OG.

Since it is largely unfermantable (about 3%) I would have though that maltodextrine would contribute basically the same to both OG and FG so that if I took 1lb and dissolved it into 1gal, then added yeast I should end up with an OG of 1.042 and an FG of about the same
I tried making up a grain with type sugar and a potential of 1.042 and used a recipe of 1lb ina 1 gal batch. If I use 100 % yield thsi gives a correct OG of 1.042 but a FG of 1.00 i.e all the sugar has been used up which isnt goiung to happen

Conversely a yield of 3% gives OG 1.001 and FG 1.000 so the software seems to be using the yield at the start of fermentation.

Anyone help me with this, obviously I have missed something basic, but it's driving me nuts. (I hate not understanding stuff !!!)

Tks Steve D
 
Hey Steve!
  It's me again. I'm really new to this, as you know, and haven't used a kit as you call it. But I believe that BeerSmith 2 allows you to set up your program in either English or Metric as needed by using the tools. You can go right to it from the BeerSmith 2, "Welcome to BeerSmith 2" start up box. Then go to to the section in that box titled,"New to Beersmith", then 3 down to, "Setting Metric/English Units". It will tell you how to set up your program for metric. That welcome box has a lot of cool links in it too. Or you can just read the following which I copied from the aforementioned link. I will be bottling my very first brew tomorrow, made from a recipe I designed. An extract brew. BeerSmith was dead on my O.G.. 1.081 when I tested it. I even put to much water in my fermenter and changed the batch size to 5.5 gallons from the original 5 gallons. I changed the batch size in the program recipe to match. It adjusted the readings and it matched what I got for test results!
  I think in addition to making the program run metric you also need to have a very accurate "Equipment Profile". Because BeerSmith adjusts things for that and also the recipe. Hope this is helpful and below is the info to make your system metric:

Using the Units Options Tab

o Select the Options dialog from the Tools menu or toolbar below the main ribbon (Preferences on the BeerSmith 2 menu for the Macintosh version).

o Click on the Units tab on the left side of the dialog

o If you want to quickly set all of your units, choose one of the buttons at the bottom of the dialog such as "Set to Metric Units" to quickly choose metric units for your default.

o If desired, you can set individual fields as well, and also adjust the precision displayed and increment size for incrementing/decrementing amounts within the recipe design dialog.

o If you are using English units, you can also show weights as pounds and ounces (such as 3 lbs 2 oz) which can help to make many recipes more readable.

o Note that in addition to the default units, BeerSmith also supports Automatic Unit Conversion in any field, so you can enter the units after a number in any field and it will do the conversion for you automatically.
 
I'm gagging for someone to answer the initial question about IBU/EBC being too high for Coopers products. I use a lot of these products and have not been able to get any value out of BeerSmith as a result.

The IBU/EBC figures provided in the Coopers Add-on are correct as per the Coopers website but obviously not measured as required by BeerSmith (just compare say the EBC of Coopers Dark Malt Extract against the EBC of the 'default' Dark Malt Extract provided by BeerSmith ... a big difference).

Cheers.
 
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