After looking at various recipes I decided on the following:
3,46 kg pale malt
1 kg Munich malt
0,5 kg wheat malt
0,25 kg rice flakes
0,1 kg Special B
Hops/flavourings/finings
2,5 kg butternut squash (before roasting) @ 70 mins
15,3 g Simcoe @ 70 mins
1 star anise @ 40 mins
0,5 kg maple syrup @ 20 mins
1 tsp irish moss @10 mins
0,5 vanillapod (split) @ 5 mins
2 cloves @ 5 mins
0,25 tsp nutmeg @ 5 mins
1 tsp ground ginger @ 5 mins
2 allspice berries (crushed) @ 5 mins
11,4 g Goldings @ 5 mins
Yeast: SafAle T-58
I cut the butternut squash in 5cm pieces and roasted them for 1 hour at 190°C.
After 40 mins I sprinkled them with a couple of tablespoons of demerera sugar.
When the pieces were cooled down, I put them in a plastic container with all the liquids that came out during roasting and put them in the fridge.
On brewday (3 days later) I took them out, cut them in 1-2 cm pieces and put them in a muslin cloth for the boil. After the boil I drained them in a coleander and added the drained off liquid to the wort.
I ended up with an SG of 1055
Had a taste from the testtube and it smelled and tasted brilliant. I could taste every flavour I put in it.
For additional flavouring I'm going to put the same spicemix in my FV 2 days before botteling.