diastatic power

From what I've read, a malt needs to have a diastatic power of 35L to self-convert. Does this mean that a malt with say a diastatic power of 70L is able to self-convert AND convert an equal amount of grain with no diastatic power?

I do partial mashes and I'm trying to figure out if I have enough base malt in a recipe to convert the specialty grains. I want to use 1.75 lbs of Maris Otter plus ~2lb of specialty malts (all with no power to convert). Will this work? Does it matter what the specialty grains are? FWIW, I am already pushing my limit on the amount of grain I can mash.

What are these specialty malts you speak of specifically? Some of the roasted malts do have some diastase and others were converted as part of the kilning process.

GilaMinumBeer said:

What are these specialty malts you speak of specifically? Some of the roasted malts do have some diastase and others were converted as part of the kilning process.

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crystal 80L ~4oz
chocolate ~6oz
roasted barley ~4oz
flaked oats ~8oz
victory ~6oz

(can you guess what I'm making? )

The only thing there that needs to be mashed is the flaked oats and the Victory. The MO has enough DE to convert them but Victory is diastatic enough* to self convert. The rest of those malt need no conversion as they were kilned green or saturated enough to self convert in the roaster, or they were never meant to be converted in the first place (roasted barley).

*Most of the listings I find for Victory state a DP of 50 on Victory.

GilaMinumBeer said:

The only thing there that needs to be mashed is the flaked oats and the Victory. The MO has enough DE to convert them but Victory is diastatic enough* to self convert. The rest of those malt need no conversion as they were kilned green or saturated enough to self convert in the roaster, or they were never meant to be converted in the first place (roasted barley).

*Most of the listings I find for Victory state a DP of 50 on Victory.

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Thanks. Of course, now that you say that I realized that I knew that (except the Victory part). I got caught up in the total weights and failed to actually think about it!

Use the average of all the grains in the mash. You have to consider them all (even the one already converted and unconvertible) because they all take up space. It's probably better to have it about 50 and that's not hard to do with a pound or two of American base malts. Lower DP may take more time for the same fermentability. I've seen a lot of old British recipes with a small percentage of six row.