Username:
Password:
News:
Welcome to the American Homebrewers Association Forum. Though you do not need to be a member to participate, we would love for you to join us!
Home
Help
Search
Members
View the memberlist
Search For Members
Login
Register
Homebrewers Association | AHA Forum
»
General Category
»
General Homebrew Discussion
»
Tinseth Hop Calculation Help
« previous
next »
Print
Pages: [
1
]
Go Down
Author
Topic: Tinseth Hop Calculation Help (Read 2229 times)
NorthernIke
Cellarman
Posts: 51
Tinseth Hop Calculation Help
«
on:
January 16, 2010, 12:50:56 PM »
I'm sick of looking up hop utilization numbers when building recipies. I use a spreadsheet that I built for my brewing "software".
I need some help building an equation in Excel. I use the Tinseth formula, and on his page on of the stated factors is "boil time factor". This is determined by this equation:
The Boil Time factor accounts for the change in utilization due to boil time:
Boil Time factor = 1 - e^(-0.04 * time in mins)
--------------------------
4.15
My question is what does "e" refer to in the above equation? How do I program this into Excel?
Here is Tinseth's page where I got the formula:
http://realbeer.com/hops/research.html
Thanks!
Logged
NorthernIke
Cellarman
Posts: 51
Re: Tinseth Hop Calculation Help
«
Reply #1 on:
January 16, 2010, 12:54:16 PM »
From Wikipedia:
http://en.wikipedia.org/wiki/E_%28mathematical_constant%29
The mathematical constant e is the unique real number such that the value of the derivative (slope of the tangent line) of the function f(x) = ex at the point x = 0 is exactly 1.[1] The function ex so defined is called the exponential function, and its inverse is the natural logarithm, or logarithm to base e. The number e is also commonly defined as the base of the natural logarithm (using an integral to define the latter), as the limit of a certain sequence, or as the sum of a certain series (see the alternative characterizations, below).
e is one of the most important numbers in mathematics,[2] alongside the additive and multiplicative identities 0 and 1, the constant π, and the imaginary unit i. (These are the five constants appearing in one formulation of Euler's identity.)
I guess I'm no Mathlete! I'm going to try and plug this into Excel...maybe it's smarter than me...
Logged
NorthernIke
Cellarman
Posts: 51
Re: Tinseth Hop Calculation Help
«
Reply #2 on:
January 16, 2010, 01:12:42 PM »
Thanks to Wikipedia..."e" can be described as:
2.71828182845904523536
This seems to make the Excel formula work like a champ! Maybe this will come in handy for someone, someday...but probably not!
Logged
a10t2
Official Poobah of No Life.
Posts: 4053
Ask me why I don't like Chico!
Re: Tinseth Hop Calculation Help
«
Reply #3 on:
January 16, 2010, 01:28:37 PM »
You can also enter it exactly (or at least, to a whole lotta digits - I don't know if Excel uses a stored value or not) by using the exp() function.
Logged
Sent from my Microsoft Bob
Beer is like porn. You can buy it, but it's more fun to make your own.
seanterrill.com/category/brewing |
twomilebrewing.com
hopfenundmalz
Official Poobah of No Life.
Posts: 6991
Milford, MI
Re: Tinseth Hop Calculation Help
«
Reply #4 on:
January 18, 2010, 05:33:42 PM »
Remember that your input data will be 2 sig. figures.
Don't quote your output IBU's to 12 decimal places.
Logged
Jeff Rankert
Ann Arbor Brewers Guild, AHA Member, BJCP Certified
Home-brewing, not just a hobby, it is a lifestyle!
skiwithg
1st Kit
Posts: 8
Re: Tinseth Hop Calculation Help
«
Reply #5 on:
January 19, 2010, 04:47:58 AM »
FYI - Tinseth was on a recent episode of Brew Strong podcast.
Logged
Print
Pages: [
1
]
Go Up
« previous
next »
Homebrewers Association | AHA Forum
»
General Category
»
General Homebrew Discussion
»
Tinseth Hop Calculation Help