No carbonation

[ThePrisoner]

I've been dissolving 1/8 cup dextrose in water and adding to 1 gallon cider then bottling and leaving 3 weeks but there is no sign of bubbles at all.
I've done this with different batches and always the same very low carbonation or none.
Wondering if I either left everything in secondary too long so the yeast are dead or if I should add more dextrose.
They were in secondary about 1 year.

 

[mac_1103]

Yeah, a year is a long time. You probably want to add yeast at bottling if you wait that long.

 

[mashdar]

You are bottling, right? Caps?

You can add significantly less yeast than for primary.

 

[hungupdown]

1/8th cup sounds fine.
I wouldn't expect to see bubbles, while carbonating in bottles.
But I usually also fill one PET (pop) bottle, as a carbonation test. It firming up, is good guide to carbonation pressure.

After a year, I'd either rouse a little of the old yeast sediment, or add fresh yeast .
I've used LalBrew® CBC-1 Cask and Bottle Conditioning Yeast (in 15% imperial stout), but know people that use bakers yeast (for regular ABV beers, @ a pinch per bottle).

 

[Chalkyt]

A pinch of DAP or similar nutrient wouldn't hurt if you add yeast. As a rough guide, check the SG after you add the fermentable sugar then add 50ppm (0.05g/L or 0.2g/gallon) of DAP for each 0.010 of SG you want to ferment back down to zero. I sometimes add a "safety dose" of about 0.1g/L DAP which is about 1/10 teaspoon per 5 litres (a "gallon") halfway through fermentation, just to ensure that the cider finishes at SG 1.000.