Minimash try

[jaydub]

Having some time to kill on Monday while I was waiting for the gas company guy to show up (convenient 8-hour window for your appointment!), I decided to get a start on a porter recipe I was going to do this weekend. I'm an extract brewer at this point, haven't ever tried mashing. Here's a look at the grain bill for my specialty grains:
1/4# British chocolate malt
3/4# British carastan 30-40L
1/4# British black patent
1/2# Crystal malt 70L
another 1/4# of a medium dark grain that I forget at the moment (work!)
all cracked fresh at my LHBS

As I was getting ready to steep I thought, hell - lets try a mini-mash. I followed the instructions Lufah posted somewhere in TBN forums and sparged into my main kettle with 1/2 gallon of 170F water and 1/2 gallon of hot tap water (treated with pot-met to get rid of chloramine). I got a nice dark trickle of runnings out, but it didn't seem particularly thick or sweet (but over the dark malts that might just have been overwhelmed). In looking at the grain bill I realized that there might not have been enough active enzymes since all the malts were roasted to some degree. Does that make sense? In planning out another minimash, should I make some allowance for pale base grain? What proportion of base malt is needed to mash the specialty grains?

I suspect I just achieved a deep steep of my specialty grains with this go.

----edit---
Victory! The grain I couldn't remember was Victory malt. LHBS guy's recipe. I have no idea what most of the specialty grains do in the recipe.

[Dr Scott]

I think you answered your own question, but let me throw in my 2 cents to see if I can clarify things a bit...
The idea behind a mini-mash is to convert the starches in "base" malt (which can't be steeped). Base malt gives you the fermentable sugars that you normally get from your extract. The mini-mash gives you a way to cut down on the amount of extract you use. You will get much better tasting beer this way (which is why we do it).
Base grain still has enzymes. All the roasted grains you used don't, because of the high kilning temps. And all the sugars in the crysal malt have already been converted during the steeping part of it's production.

Just think:
Base malt & adjuncts (ie. Corn and rice)= fermentables (must be mashed)
Specialty grains= color and flavor (which you can get from steeping or mashing)

Short answer: You need to use base malts (two row, pils,etc) in the mini-mash. The amount depends on the portion of extract you want to replace.
I hope this helps.
Cheers, Dr Scott

[pvignola]

I believe that you should at least have a 1:1 ratio of base malt with specialty grains?