homebrew cider second attempt: backsweetening

NB this didn't work that well b/c I should have also added potassium metabisulfite.

Tue Feb 22, 2022

 5 gallons cider, Carlson Orchard - pasteurized but no additives (especially no potassium sorbate)

1 yeast packet (1 oz.) Red Star Premiere Blanc (formerly champagne yeast)

Sterilized equipment (carboy, funnel, airlock).  Poured cider into carboy, added yeast, put on airlock.

Friday Mar 18, 2022 9:40 PM

Added 2.5 tsp of potassium sorbate.  Mixed carboy thoroughly

*** should have added postassium metabisulfite ***. Sorbate stops yeast from dividing, does not stop them from fermenting.

backsweetening reference

backsweetening calculation

1st batch of hard cider came out very dry - assume it is between 0 and 9 g/L sugar based on reference above.  Assume it is 0 g/L, then if I get it to 9 g/L, it is at the boundary between dry and medium and will be sweeter than previously, but definitely not too sweet.  If it starts at 9 g/L

target 9 g/L = 2.1 g / cup

initial volume:  5 gallons * 16 cups/per gallon = 80 cups

x = # cups of apple cider to add

sugar amount:  (24 g/cup) * (x cups)

total volume:  x + 80 cups initial volume

sugar concentration (g/cup) s = 24*x / (x + 80)

target concentration:  2.1 g/ cup

2.1 = 24x/(x+80)

2.1*(x+80) = 24x

2.1*x + 168 = 24x

21.9*x = 168

x = 7.67 cups

What happens if initial amount of sugar is not zero?

residual sugar amount:  80 cups * (y g/cup residual sugar)

sugar concentration is:  (24*x + 80*y) / (x + 80)

assume x=8 from above, then sugar concentration is:

s = (192 + 80*y) / 88 = 2.2 + 0.91*y

if y is 2.1 g/cup then sugar concentration is:

s = 2.2 + 0.91*2.1 = 2.2 + 1.8 = 4 g/cup

This is still in the "medium" cider range, closer to the dry end of the scale.