Chromabrew

Convert SRM, EBC, or a list of Lovibond values to another color scale, or to a hex color.

Color values are provided by Barley Dog Brewery here

Usage

Install the library:

npm install --save chromabrew

Require the module:

let chromabrew = require('chromabrew');

Pass options which describe a batch to the Batch constructor, or directly to the required module. See the list of accepted options below. Call hex on the returned object to get a color:

new chromabrew.Batch({ srm: 4 }).hex();
// => '#ECE61A'

chromabrew({ srm: 4 }).hex();
// => '#ECE61A'

chromabrew({ ebc: 4 }).hex();
// => '#F8F753'

Convert between color scales:

let batch = chromabrew({ srm: 4 });

batch.srm();
// => 4

batch.ebc();
// => 7.88

batch.mcu();
// => 4.210535199414287

batch.lovibond();
// => 3.407407407407407

Specify which calculation method was used to determine the provided srm or ebc, or which method to use when converting between scales:

let batch = chromabrew({ srm: 14, calculator: 'daniels' });

batch.srm('daniels');
// => 14

// defaults to 'morey'
batch.srm();
// => 14.670088349307665

batch.srm('mosher');
// => 13.099999999999998

// defaults to 'morey'
batch.ebc();
// => 28.9000740481361

batch.hex('daniels');
// => '#B26033'

// defaults to 'morey'
batch.hex();
// => '#A85C37'

Options

Primary Options

Any one of the following options must be passed to the module:

| option | description | type | |-|-|-| | srm | the SRM of a batch | Number | | ebc | the EBC of a batch | Number | | l or lovibond | the degrees Lovibond of a batch | Number | | batch | options describing a batch in detail (see below) | Object |

This option may be used in combination with a known color value (srm, ebc, or l) to specify which calculation method was used:

| option | description | type | |-|-|-| | calculator | the SRM calculation method used: 'morey' (default), 'daniels', 'mosher', or 'barry' † | String |

† apparently they let anyone create a beer color scale

Batch Options

The following options define the batch primary option:

| option | description | type | |-|-|-| | mcu | the MCU of the batch, if it is already known | Number | | v or volume | the total liquid volume of the wort (required) | Number | | ingredients | an Array of ingredient options (see below; required) | Array[Object] | | litres or liters | whether volume is expressed in litres | Boolean | | kilograms or kilos | whether weight of each item in ingredients is expressed in kilograms | Boolean | | metric | shortcut to apply both litres and kilograms options | Boolean |

Ingredient Options

The following options define each ingredient in the ingredients batch option:

| option | description | type | |-|-|-| | l or lovibond | the value in degrees Lovibond of the ingredient (required) | Number | | w or weight | the weight of the ingredient used (required) | Number |

Functional Domain

The domain of valid inputs is 0 through 40 SRM. Input values are rounded to the nearest 0.1 SRM within this domain:

chromabrew({ srm: -1 }).hex() === chromabrew({ srm: 0 }).hex();
// => true

chromabrew({ srm: Number.MAX_VALUE }).hex() === chromabrew({ srm: 40 }).hex();
// => true

chromabrew({ srm: Math.PI }).hex() === chromabrew({ srm: 3.1 }).hex();
// => true  

The 'daniels' and 'mosher' SRM calculation scales have a minimum result of 8.4 and 4.7, respectively. Where a provided srm would result in a negative mcu, the mcu is set to 0:

let daniels = chromabrew({ srm: 4, calculator: 'daniels' });

daniels.mcu();
// => 0

daniels.srm();
// => 0

daniels.srm('daniels');
// => 8.4

let mosher = chromabrew({ srm: 4, calculator: 'mosher' });

mosher.mcu();
// => 0

mosher.srm();
// => 0

mosher.srm('mosher');
// => 4.7