Choc malt tastes more of coffee than chocolate.
Substitute with Choc Chit or even Carafa Special T2 all steepable to get away from the roasted coffee taste. Probably need lactose to get a sweet chocolate type taste.
BTW I am one who thinks chocolate in stout is horrible and only true dry stouts rule.
A nice dry sharp bitter stout with a very sweet desert works rather well :icon_cheers:
edit: I reckon you will have to boil at 100 C or a bit above depending on concentrations and altitude.
1 x Thomas Coopers Irish stout
1 x tin pale malt extract or 1 kg pale DME
250 g choc malt (steeped)
200-500 g lactose
200g brown sugar
(optional) 200g organic cocoa
10g fuggles@ 30
10g EKG @10
US 04 or 05
30 minute boil, 5 - 10 litres, add dry malt at beginning, add tins 10 minutes before end, hops at appropriate points.
Roast barley tastes of coffee but I wouldn't associate it with choc malt. I usually add lactose to my stouts .