After transcribing the data presented in Yakima Chief Hops (YCH) “Survivables” Chart, I dusted off my algebra skills to find which combination(s) of hops is similar to YCH’s TRI-2304CR cryo hops blend.

YCH released TRI-2304CR this past year based on research from the 2019 hops harvest. The technical webinar is available on the YCH website and a thorough recap is also available courtesy of Scott Janish. To summarize, YCH analyzed seven unique hop compounds that best “survive” the brewing process (aka have the greatest staying power through to the finished beer) in 35 different hop varieties (see “Survivables” Chart link above). Later, YCH produced a cryo hops blend that maximizes biotransformation potential, load the whirlpool and early dry hop with “survivable” compounds, contains high levels of geraniol, linalool, 3MH and methyl geranate, targets synergies between hop compounds and delivers a flavor pop! The resulting cryo hops blend (temporarily named TRI-2304CR) features the highest total “survivable” compounds.

The only issues with TRI-2304CR were that YCH produced relatively small amounts and did not make available to homebrewers. After transcribing the YCH data, I set out to reverse engineer TRI-2304CR to reveal which combination(s) of hops is similar to its “survivable” compounds levels.

* TL;DR: A blend of 46% Idaho 7 / 25% Citra / 24% Loral / 5% HBC 692 is closest to TRI-2304CR while a blend of 65% Idaho 7 / 33% Mosaic / 2% Citra maximizes each “survivable” compound level*.

I used Octave to solve a system of linear equations to determine the hop blends. Using the formula x = A \ b (where A = M-by-N multiplier matrix and b = M-by-1 constant vector) yielded an exact match to TRI-2304CR but included negative values for some hop varieties and did not sum to 1 (100%). I refined the solution by optimizing the system of linear equations to force solutions to be non negative and sum to 1. I solved four different scenarios:

- Hops blend (which I call “Cryo 7” or x1) with “survivable” compounds levels closest to TRI-2304CR
- Hops blend (which I call “Cryo 4” or x2) with methyl geranate, linalool, geraniol and 3MH compounds levels closest to TRI-2304CR
- Hops blends (which I call “Max 7” or x3) with maximum “survivable” compounds levels
- Hops blend (which I call “Max 4” or x4) with maximum s methyl geranate, linalool, geraniol and 3MH compounds levels

Below is an explanation of the Octave commands:

```
%% A is a M-by-N multiplier matrix, where M is the number of equations, and N is the number of elements of x
A1 = [19,92,153,148,64,64,189; . . . 3,6,50,61,6,17,56]
%A1 includes all 7 "survivable" compounds levels for the 35 hop varieties
A2 = [92,148,64,189; . . .6,61,6,56]
%A2 includes methyl geranate, linalool, geraniol and 3MH compound levels for the 35 hop varieties
```

```
%% b is a M-by-1 constant vector, where M is the number of equations
b1 = [31;125;117;250;106;19;136]
% b1 is the 7 "survivable" compounds levels for TRI-2304CR
b2 = [125;250;106;136]
% b2 is the methyl geranate, linalool, geraniol and 3MH compound levels for TRI-2304CR
b3 = [42;223;164;306;167;64;342]
% b3 is the maximum 7 "survivable" compounds levels
b4 = [223;306;167;342]
% b4 is the maximum geranate, linalool, geraniol and 3MH compound levels
```

```
%% Aeq is a Me-by-N linear equality constraint matrix where Me is the number of equalities and N is the number of variables
Aeq = ones(1,35)
% Aeq = ones(1,N) specifies the x components to sum to 1
```

```
%% beq is a linear equality constraint Me-element vector related to the Aeq matrix that encodes the Me linear equalities
beq = 1
% beq = 1 specifies the x components to sum to 1
```

```
%% lb is a vector that represents the lower bounds of the x components
lb = [0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0]
```

```
%% ub is a vector that represents the upper bounds of the x compoents
ub = [1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1;1]
```

```
%% lsqlin solves constrained linear least-squares problems
x1 = lsqlin(A1,b1,[],[],Aeq,beq,lb,ub)
% x1 returns the hops blend closest to the 7 "survivable" compounds levels for TRI-2304CR
x2 = lsqlin(A2,b2,[],[],Aeq,beq,lb,ub)
% x2 returns the hops blend closest to the methyl geranate, linalool, geraniol and 3MH compound levels for TRI-2304CR
x3 = lsqlin(A1,b3,[],[],Aeq,beq,lb,ub)
% x3 returns the hops blend with the maximum 7 "survivable" compounds levels
x4 = lsqlin(A2,b4,[],[],Aeq,beq,lb,ub)
% x4 returns the hops blend with the maximum geranate, linalool, geraniol and 3MH compound levels
```

The results for x1 – x4 can be found below:

Hop Blend | TRI-2304CR | Cryo 7 | Cryo 4 | Max 7 | Max 4 |

x | N/A | x1 | X2 | x3 | x4 |

Components | N/A | 46% Idaho 7 25% Citra 24% Loral 5% HBC 692 | 38% Idaho 7 33% Citra 22% Loral 7% HBC 692 | 65% Idaho 7 33 % Mosaic 2% Citra | 63% Mosaic 27% Idaho 7 10% Citra |

$ / oz | N/A | $1.19 | $1.21 | $1.27 | $1.37 |

BluButanoic acid,3-methylbutyl estere | 31 | 14 | 13 | 21 | 21 |

Methyl geranate | 125 | 111 | 117 | 127 | 165 |

2MIB | 117 | 95 | 87 | 121 | 86 |

Linalool | 250 | 208 | 211 | 145 | 148 |

Geraniol | 106 | 55 | 55 | 64 | 63 |

2-Nonanone | 19 | 33 | 29 | 52 | 38 |

3MH | 136 | 117 | 110 | 180 | 165 |

Total ppm | 784 | 633 | 622 | 710 | 686 |

In summary;

- 46% Idaho 7 / 25% Citra / 24% Loral / 5% HBC 692 is the hops blend closest to all seven “survivables” compounds levels in TRI-2304CR (“Cryo 7”)
- 38% Idaho 7 / 33% Citra / 22% Loral / 7% HBC 692 is the hops blend closest to methyl geranate, linalool, geraniol and 3MH levels in TRI-2304CR (“Cryo 4”)
- 65% Idaho 7 / 33 % Mosaic / 2% Citra is the hops blends that maximizes all seven “survivables” compounds levels (“Max 7”)
- 63% Mosaic / 27% Idaho 7 / 10% Citra is the hops blend that maximizes methyl geranate, linalool, geraniol and 3MH levels (“Max 4”)

Unfortunately, I was unable to exactly replicate TRI-2304CR given the data presented by YCH. It’s likely that the “survivables” chart was incomplete since seven additional hops (Pahto, Columbus, Zeus, Tomahawk, CTZ, HBC 735 and Centennial) were also analyzed and presented on a 3HM-only slide. I hope that YCH includes the “survivable” compounds levels for each variety from the 2020 harvest on their website like they currently do for alpha acid, beta acid, total oil, co-humulone, b-pinene, myrcene, linalool, caryophyllene, farnesene, humulene and geraniol. If they do, I will rerun the system of linear equations to find an even closer (or perhaps even an exact match) to TRI-2304CR.

Keep in mind, the results above produce blends that approximate specific “survivable” compounds levels but do not guarantee similar flavor and aroma intensity to TRI-2304CR.

If YCH eventually makes TRI-2304CR available to homebrewers I will be able to trial the four hops blends above to see which delivers similar flavor and aroma intensity to TRI-2304CR. In the meantime, I plan to brew four iterations of Mountain IPA to see which hops blends provides the greatest flavor pop!