Extract Brewing with Specialty Grains

[izumidai]

What is the efficiency of extraction when steeping specialty grain?

I am asking because I don’t want to use kits anymore and I am trying to come up with an extract recipe for an ordinary bitter. For a possible grain bill, I was thinking 1.035 for a SG using 89% M&F light DME, 8% Crystal 40 and 3% Carapils. For a 5.5 gallon batch, the Ray Daniels book says that I am going to need 192.5 gravity units. I calculated that I will need about 3.8lbs of the light DME to get my 172 GU’s, but what efficiency should I use to calculate my two specialty grains. Since I am not mashing anything, I am assuming that my efficiency will be much lower than the 68% percent average that is used in the book when mashing. I have seen some articles state that steeping will give you an efficiency of 20 to 30 percent? If this is true, should I then use somewhere in the ballpark of 25% to calculate the amount of specialty grains needed? Using 25% as my efficiency would then give me results of about 1.8lbs of crystal 40 and .7lbs of carapils. Finally, how close will the results be of steeping these amounts of specialty grains be compared to the results of mashing the smaller amounts required if I was mashing at 68% efficiency?
Any insight would be greatly appreciated.

[ionia_ales]

Efficiency isn't too vital for extract brews. Just try to figure the weights.. .like .25 lb or .5, and steep them. You will be getting color and a bit of malt flavor and not really converting/extracting sugars. Your math is right -sort of but it's more important for AG.

Since you're not mashing your eff. will be very low. Again, that's for people using basemalt- and figuring how much of the potential sugars were extracted. I'd get your GU's from the extract, but I don't think this is quite right...

"Using 25% as my efficiency would then give me results of about 1.8lbs of crystal 40 and .7lbs of carapils" I can't figure the weight for the 89% - 8%-3% figures but I would guess that for a 5 gallon batch 1.8lbs of crystal is too much. - maybe 1 lb, I'd guess more like .5lb of crystal and .25 of cara-pils. - Hopefully we can get some more thoughts on this.