I've been looking at making a beer resembling NB Frambozen, and I found this:
"Jason, of the New Belgium Brewing Company in Fort Collins, Colorado, has been with NBB for three years. He previously worked at Abita Brewing Company in Abita Springs, Louisiana. He attended the diploma course at the
Frambozen — a fruited brown ale of Belgian origin — was first brewed by New Belgium Brewing Company during the winter of 1992.
Our Frambozen is not a traditional Christmas beer in any sense, but the high gravity makes it a great winter warmer, and the full raspberry flavor gives you a refreshing memory of stopping to snack on wild raspberries during long mid-summer hikes.
If you would like to brew this beer at home, I would shoot for an OG of 1.064. The mash should be roughly 75 percent pale malt, 10 percent Munich malt, 4 percent sugar, 10 percent caramel malt, and 1 percent chocolate malt. Add corn sugar during the boil.
Bittering hops are very low. roughly 20 IBUs. Add these hops early in the boil. We hop very minimally for flavor or aroma as we find that the hops will conflict with the fruit characteristics of the finished beer. Ferment down to 1.014 FG, holding temperatures barely above 68° F. Use a neutral ale yeast (like Wyeast 1056) or a Belgian ale yeast, or even both. After fermentation rack your beer off the yeast and chill it around 30° F if possible.
After 2 weeks of aging, rack your beer (being careful not to transfer any sediment) onto raspberry pulp. This pulp should equal 20% of your total beer volume, so if you are making five gallons of beer, you should rack onto 1 gallon of pulp. If you use raspberry juice, decrease the amount to 10% of your total beer amount (1/2 gallon for a 5-gallon batch). The high alcohol content should eliminate any sanitation concerns but wash the berries as well as possible.
Rack off the raspberry pulp after about two weeks, then let your batch settle again for several days before bottling."
I think this gives enough information to understand exactly how NB's beer is made, and a great starting point to make my own. Cheers!