Personally I tend to prefer caramunich over the crystal, so id swap the 60 with some cara-aroma.. Not really sure about amounts, 150g is nice but it depends.
Speaking of wheat, I just had a go at my Experiwheat and, man is that different!
You are talking about wheat crispening things up a bit.. well I can say, that at 60% wheat is very crisp! Even at those sorts of percentages, it doesn't lend much flavour - or body... very dry - you know, like cranberry juice (sort of).
Anyway - wheat is very common in a lot of English recipes for adding a bit of fluff to the head. They use torrified wheat for that too.
It's like a shandy, in a way. There is beer flavour in there, but the wheat is quite lemony on it's own. It finished at 1.008 - even with a 68 degree mash and it has this soft bitterness from the Nugget. I wouldn't even say it was like an American wheat - the ones I had of those were like German ones without the Banana... Maybe American Hefe yeast would be good for your Roggenbier type of thing.
It's still a bit green - but it is the perfect summer session beer... even at 5.9%
You can only just taste the alcohol in it amongst the lemon grass - it's very interesting.
5kg Marris Otter
200g crystal
150 g roasted barley
150 g pale chocolate
I used the wyeast West yorkshire (very nice). I too was trying to acheive an ale with a more complex malt character. I think that yeast, is most excellent for what you are trying to achieve. Malts, are whatever you are trying to achieve, as far as taste is concerned. I tried a stepped mash, in order to achieve a more complex characteristic.
I think I acheived my aim, only I think the brew has contracted an infection, in the secondary (totally bummed). The first time this has happened to me, I'll see how it develops?
There was a white, powdery flecks floating on top and it smelled a little phenollicy. I did taste test it and it didn't taste off, but then it hasn't conditioned yet. I did bottle it in the hope that it was a figment of my imagination. Time will tell. I was very happy with how it tasted out of the hydrometer tube and there were definative complex malt characters early on. It finished up at 6.8%ABV, so it is a real kicker.
I too am looking at at brewing a porter style beer with similar malts. I have:
Marris Otter
Pale Choc
Chocolate
Light Crystal
Cara-aroma.
I was thinking of hopping with US Wilamette & NZ cascade to around 35ibus and using US-05 (unless my northwest ale yeast turns up by friday). Any thoughts on splitting the grain bill?