How long for fermentation

[moonspoon]

How do you calculate

 

[theSeekerr]

This calculator is good: https://www.brewersfriend.com/abv-calculator/

The alternate equation option may be a little more accurate, but they'll be within about 0.2% until you get to fairly high ABV anyway.

 

[moonspoon]

Cool i was using og-fg x131.25

 

[theSeekerr]

Cool i was using og-fg x131.25

That's a reasonable approximation, but you must have messed up your original calculation: (1.050 - 1.001) = 0.049, 0.049 * 131.25 = 6.43%

 

[peterlonz]

Regarding yeast nutrient for cider making: I usually add about 200 grams of of plain light malt extract to provide nutrient. Mainly because I rarely see commercial nutrient for sale. Anyway I believe the malt improves the flavour profile.

 

[Fro-Daddy]

Day 13 seems quick, mine is currently on day 23 and the gravity is still dropping (1.010 on day 21). I am fermenting at 12°C which might slow things down.