Dark Grains At Mash's End?

I've been perusing through a variety of porter recipes and have found quite a few that add their dark grains during the vorlauf or during the sparge process.

I've never come across this so I'm a little surprised. I suppose you're not converting much sugars from those grains so the extended time in the mash doesn't matter as much. But would you lose some color from not letting it rest with the rest?

Is there any benefit other than pH control?

The benefit is supposed to be a smoother finish without a harsh roast bite.  pH control is a secondary benefit for a few brewers.  Personally, I've never had an issue with getting in the 'sweet spot' of pH during the mash even for stouts with a high level of roasted barley. 

When I tried it (once), I found that I ended up with a much lighter beer than I had expected.  Judging by the color of the beer, I probably would have had to double or triple the amount of roasted malts to get the color I wanted.  That said, it may have been my technique (batch sparge), but I doubt it.

Thanks for the reply.

Yeah I was concerned about the color and potential body that would be lost in this method. I also batch sparge and feel like fly sparging would benefit more to this practice.

I use mash capping for all my mid to dark crystals and roasted grains. I think it's important to include recirculating mash to get the needed color. My $.02.

Mark

I have been doing this since reading Gordon Strong's book "Brewing better Beer". Gordon adds all of his dark and crystal malts during vorlauf because they don't need to be mashed and he feels the dark malts in particular will add unnecessary astringent bitterness.
I batch sparge and haven't noticed any loss in color and I feel the flavor from grain like black patent is smoother but still very present. I have made Denny Conn's BVIP using this method and I feel that the results were spectacular.
I think that you should give it a try on one batch without altering your recipe, i.e. the amount of dark grains, and let us know what you think.
You should also give Gordon's book a read, I borrowed it from my local library before buying a copy from him at my LHBS where he was doing a demo and selling and signing his books!
Good luck!

The one thing that I've seen people do when adding dark malts at the end of the mash for color is to run the grain through a coffee grinder and powder it so you get a really fast color extraction without harshness normally associated with dark malts.

Greetings All - I have made several porters (my favorite style) adding all my grains at once and have had no ill effects. In fact, my porters and brown ales are in high demand with my friends and family. I happen to like the roasted flavor from the darker grains and if there is a little "bite", I'm okay with it.  I suppose whatever floats your boat!