brew.utilities.yeast

class brew.utilities.yeast.YeastModel(method, units=u'imperial')
METHOD_TO_GROWTH_ADJ = {u'shaking': 0.0, u'stir plate': 0.0, u'no agitation': 0.0}
get_growth_rate(inoculation_rate)
get_inoculation_rate(growth_rate)
get_resulting_pitch_rate(starter_cell_count, original_gravity=1.036, final_volume=5.0)
get_starter_volume(available_cells, starter_volume=0.5283443537159779, original_gravity=1.036)

Calculate the number of cells given a stater volume and gravity

get_viability(days_since_manufacture)

Yeast viability drops 21% each month or 0.7% per day from the date of manufacture. Assume linear change.

get_yeast_pitch_rate(original_gravity=1.05, final_volume=5.0, target_pitch_rate=1.42, yeast_type=u'liquid', cells_per_pack=100, num_packs=1, days_since_manufacture=30)

Determine yeast pitch rate

original_gravity - specific gravity of original beer final_volume - volume of the batch post fermentation target_pitch_rate - million cells / (ml * degP) yeast_type - liquid, dry cells_per_pack - Billions of cells num_packs - how many in units days_since_manufacture - the older the yeast the less viable units - imperial, metric

Yeast Viability: lose 20% viability / month or 0.66% / day

Imperial: B / Gal / GU Metric: M / ml / Plato

Sources: - http://beersmith.com/blog/2011/01/10/yeast-starters-for-home-brewing-beer-part-2/

set_units(units)
class brew.utilities.yeast.KaiserYeastModel(method=u'stir plate', units=u'imperial')

Kaiser Yeast Model

Only works for Stir Plage Growth

Sources:

METHOD_TO_GROWTH_ADJ = {u'stir plate': 0.0}
get_growth_rate(initial_cells)

initial_cells - Billion / gram extract (B/g)

get_inoculation_rate(growth_rate)
get_resulting_pitch_rate(starter_cell_count, original_gravity=1.036, final_volume=5.0)
get_starter_volume(available_cells, starter_volume=0.5283443537159779, original_gravity=1.036)

Calculate the number of cells given a stater volume and gravity

get_viability(days_since_manufacture)

Yeast viability drops 21% each month or 0.7% per day from the date of manufacture. Assume linear change.

get_yeast_pitch_rate(original_gravity=1.05, final_volume=5.0, target_pitch_rate=1.42, yeast_type=u'liquid', cells_per_pack=100, num_packs=1, days_since_manufacture=30)

Determine yeast pitch rate

original_gravity - specific gravity of original beer final_volume - volume of the batch post fermentation target_pitch_rate - million cells / (ml * degP) yeast_type - liquid, dry cells_per_pack - Billions of cells num_packs - how many in units days_since_manufacture - the older the yeast the less viable units - imperial, metric

Yeast Viability: lose 20% viability / month or 0.66% / day

Imperial: B / Gal / GU Metric: M / ml / Plato

Sources: - http://beersmith.com/blog/2011/01/10/yeast-starters-for-home-brewing-beer-part-2/

set_units(units)
class brew.utilities.yeast.WhiteYeastModel(method=u'no agitation', units=u'imperial')

Sources:

INOCULATION_CONST = [-0.999499, 12.547938, -0.459486]
METHOD_TO_GROWTH_ADJ = {u'shaking': 0.5, u'stir plate': 1.0, u'no agitation': 0.0}
get_growth_rate(inoculation_rate)

initial_cells - Billion / gram extract (B/g)

G = (12.54793776 * x^-0.4594858324) - 0.9994994906

get_inoculation_rate(growth_rate)
get_resulting_pitch_rate(starter_cell_count, original_gravity=1.036, final_volume=5.0)
get_starter_volume(available_cells, starter_volume=0.5283443537159779, original_gravity=1.036)

Calculate the number of cells given a stater volume and gravity

get_viability(days_since_manufacture)

Yeast viability drops 21% each month or 0.7% per day from the date of manufacture. Assume linear change.

get_yeast_pitch_rate(original_gravity=1.05, final_volume=5.0, target_pitch_rate=1.42, yeast_type=u'liquid', cells_per_pack=100, num_packs=1, days_since_manufacture=30)

Determine yeast pitch rate

original_gravity - specific gravity of original beer final_volume - volume of the batch post fermentation target_pitch_rate - million cells / (ml * degP) yeast_type - liquid, dry cells_per_pack - Billions of cells num_packs - how many in units days_since_manufacture - the older the yeast the less viable units - imperial, metric

Yeast Viability: lose 20% viability / month or 0.66% / day

Imperial: B / Gal / GU Metric: M / ml / Plato

Sources: - http://beersmith.com/blog/2011/01/10/yeast-starters-for-home-brewing-beer-part-2/

set_units(units)
yeast.pitch_rate_conversion(pitch_rate, units=u'imperial')

Pitch Rate Conversion

Input should be given in: Imperial: B / (Gal * GU) SI: B / (L * P)

Note: 1 M / (ml * P) == 1B / (L * P)