--- a/src/Utils.cpp Thu Jul 07 09:54:42 2022 +0200
+++ b/src/Utils.cpp Thu Jul 07 14:17:53 2022 +0200
@@ -379,48 +379,33 @@
* Formula is from the 'Mash Made Easy' spreadsheet.
* https://mashmadeeasy.yolasite.com/
* https://www.homebrewtalk.com/threads/a-rather-simplified-whirlpool-hop-ibu-computation-method.701093/
+ *
+ * Source of the formula Mark G. Malowicki.
*/
double Utils::IBU_reduction(double Tc)
{
- return (2.39 * pow(10, 11) * pow(2.71828182846, - (9773 / (Tc + Kelvin))) ) * 1/1.009231744;
+ /*
+ * Original formula plus a small correction factor.
+ */
+ return (2.39 * pow(10, 11) * exp(-(9773 / (Tc + Kelvin))) ) * 1/1.009231743647;
}
-double Utils::boilIBU(int Form, double SG, double Volume, double Amount, double Time, double Alpha, int Method)
+double Utils::TinsethIBU(double SG, double Volume, double Amount, double Time, double Alpha)
{
- double ibu = 0.0, sgfactor, boilfactor;
-
double alpha = Alpha / 100.0;
double mass = Amount * 1000.0;
- if (Method == 0) { // Tinseth
- /* http://realbeer.com/hops/research.html */
- double AddedAlphaAcids = (alpha * mass * 1000) / Volume;
- double Bigness_factor = 1.65 * pow(0.000125, SG - 1);
- double BoilTime_factor = ((1 - exp(-0.04 * Time)) / 4.15);
- ibu = Bigness_factor * BoilTime_factor * AddedAlphaAcids;
- }
- if (Method == 2) { // Daniels
- if (Form == 2) // Leaf
- boilfactor = -(0.0041 * Time * Time) + (0.6162 * Time) + 1.5779;
- else
- boilfactor = -(0.0051 * Time * Time) + (0.7835 * Time) + 1.9348;
- if (SG < 1.050)
- sgfactor = 0;
- else
- sgfactor = ((SG * 1000) - 1050) / 200;
- ibu = (mass * (alpha * 100) * boilfactor * 0.1) / (Volume * (1 + sgfactor));
- }
- if (Method == 1) { // Rager
- boilfactor = 18.11 + 13.86 * tanh((Time * 31.32) / 18.27);
- if (SG < 1.050)
- sgfactor = 0;
- else
- sgfactor = ((SG * 1000) - 1050) / 200;
- ibu = (mass * (alpha * 100) * boilfactor * 0.1) / (Volume * (1 + sgfactor));
- }
+ /*
+ * Basic Tinseth formula.
+ * http://realbeer.com/hops/research.html
+ */
+ double AddedAlphaAcids = (alpha * mass * 1000) / Volume;
+ double Bigness_factor = 1.65 * pow(0.000125, SG - 1);
+ double BoilTime_factor = ((1 - exp(-0.04 * Time)) / 4.15);
+ double ibu = Bigness_factor * BoilTime_factor * AddedAlphaAcids;
- //qDebug() << "boilIBU" << Form << SG << Volume << Amount << Time << Alpha << Method << "IBU:" << ibu;
+ qDebug() << "boilIBU" << SG << Volume << Amount << Time << Alpha << "IBU:" << ibu;
return ibu;
}
@@ -428,6 +413,8 @@
double Utils::toIBU(int Use, int Form, double SG, double Volume, double Amount, double Boiltime, double Alpha,
int Method, double Whirlpool9, double Whirlpool7, double Whirlpool6, double Fulltime)
{
+ double loss_boiltemp = 1.0; /* Loss due to the lower boil temperature at higher altitude. */
+
double ibu = 0.0, whirlibus = 0.0;
double alpha = Alpha / 100.0;
double mass = Amount * 1000.0;
@@ -477,7 +464,7 @@
* IBU's from hops during Mash, FWH and boil.
*/
if ((Use == HOP_USEAT_MASH) || (Use == HOP_USEAT_FWH) || (Use == HOP_USEAT_BOIL)) {
- ibu = boilIBU(Form, SG, Volume, Amount, Fulltime, Alpha, Method);
+ ibu = TinsethIBU(SG, Volume, Amount, Fulltime, Alpha);
/*
* Corrections for Mash and FWH
*/
@@ -502,8 +489,12 @@
} else if (Form == HOP_FORMS_EXTRACT) {
// Nothing for now.
}
-// ibu *= IBU_reduction(boilPoint());
-// qDebug() << "ibu" << ibu << IBU_reduction(boilPoint());
+
+ if (Method > 0) {
+ loss_boiltemp = IBU_reduction(boilPoint());
+ ibu *= loss_boiltemp;
+ qDebug() << "ibu" << ibu << "loss_boiltemp" << loss_boiltemp;
+ }
// } else if (Use == HOP_USEAT_AROMA) {
/*
@@ -515,7 +506,6 @@
// qDebug() << "whirlibus" << whirlibus << Use;
}
-
return round((ibu + whirlibus) * 100.0) / 100.0;
}
