CHRIS MASTERJOHN, PhD: Italian roast, so-called heavy roast, darker than dark, triples the amount of available niacin.

The nice and content in coffee is useless unless the coffee is processed right.

Roasting coffee frees the niacin.

Decaffeinating coffee gets rid of the niacin.

So we want a dark roast.  We want a strong coffee.  And we want that caffeine. 

Compared to light roast, dark roast coffee doubles the niacin content in coffee.

Italian roast, so-called heavy roast, darker than dark, triples the amount of available niacin.  

Decaffeination, by contrast, cuts the amount of niacin by half.

No it also depends on how strong you like your coffee the niacin is not in the water the niacin is in the beans.  When you make coffee about 85% of the niacin in the coffee beans will come into your cup.  But if you make your coffee with 5 G of niacin versus 10 G of niacin you're getting half the

As a rule of thumb you want about 10 G of coffee per cup to consider that a good source of niacin.  I just measured mine and when I make a double shot of expresso, I weighed it out and I get about 12 grams of coffee in that doubt shot.  It all depends on how strong you want it.  If you make weak coffee, it'll be a weak source of niacin.  If he makes strong coffee it'll be a proportionately better source of niacin.

Science says you want your coffee strong and you want your coffee dark.  

Ancestral Supplements, Collagen.