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?
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…
