Espresso and High Gravity Questions

I've used espresso in beers a bunch, and almost every time its been with Black Cat... that being said, I've found that I need ~10-20 oz of espresso for a 5 gallon batch to produce a noticeable, pleasing coffee flavor.

I've never used beans at flameout, just because I'm scared to death of picking up astringent, burnt coffee flavors and feel like I can control the coffee flavor better by adding dry beans in secondary (~0.5 oz/gallon for 24-48 hours for subtle flavor/aroma, ~1 oz/gallon for 24-48 hours for more aggressive, in your face flavor/aroma without any associated bitterness). Some people like to add cold pressed, but personally, I personally like dry beaning, as its like a giant cold press using the beer as the water, and doesn't dilute your beer like adding cold pressed or espresso would.

The KBS clone combines 2 oz at flame out and 2 oz cold pressed at bottling or secondary. If you want to recreate the KBS clone, you can do exactly what they've said and replace with black cat, although since I've never had KBS fresh, I'm not sure how coffee heavy it is compared to Breakfast Stout which is big, bitter coffee.

Regarding high gravity beers, a little info on your system would help out... e.g. kettle/cooler size, sparge method, etc.

 

I grind the beans up coarsely and add them to a muslin bag. No sanitization necessary. I typically do the "dry bean" for 24 hours and taste after then. Don't go longer than 48 hours, or you'll risk picking up vegetal flavors.

The 10-20 oz per 5 gallons referred to using liquid espresso, whereas the 1 oz per gallon referred to using coarse ground beans in secondary.

When I had smaller kettles, I would crush a little finer for big beers and include a mash out. Sometimes I'd include an extra batch sparge or two, collect extra and do a 120 minute boil.