Recipie conversion

I have read a few different methods to partial mash and i want ot make the swithc from extract with steeping grains. I will most likely use death brewers method or the method outlined here: http://menuinprogress.com/2009/02/partial-mash-brewing-and-ipa-recipe.html

Anyone see a big plus or minus to either method, i have 2 pots for db's method and i can get cooler for the other so equipment is a non issue....

Lastly, is there a rule of thumb or method in which i can convert an AG or extract into partial mash recipes? I'm just not sure how much grain to add, which grains need more or less added (obviously depends on brew style) and how much extract to remove, as well as if i need to adjust hop quantities to account for any change in utilization...

Prolly going to use the IPA in the provided link for my first round just for simplicity sake...

1 lb pale malt = 0.75 lb malt extract syrup = 0.6 lb dry malt extract.

So, if the recipe calls for 6.6 lbs of LME, you need 8.25 lbs of pale malt (6.6*1.25). From that, you can convert it back. If you want to use 3 lbs of that pale malt in a partial mash, convert 5.25 lbs of pale malt back to LME by multiplying by 0.75, or 3.9375 lbs of LME, which you then round up to 4 lbs.

You dig?

Bob

Does that work for carapils, black patent, choc malt, 40l 20l crystal as well?

You don't convert your specialty grains generally, only the base malt. Otherwise you're completely changing the recipe.

First figure out how many lbs of grain you're able (or willing) to mash. Then take whatever specialty grains and adjuncts called for in the recipe, add enough base malt for good starch conversion (up to your total mashing ability) and then convert the rest of the base malt amount to extract using the formula that NQ3X gave. For instance, I can mash 4.5 lbs of grain comfortably in my 2 gallon cooler (using a grain bag), so I'd convert like this:

Original grainbill (not a real recipe mind you):
11 lb pale malt (2-row)
1 lbs Crystal 20L
.5 lbs Vienna malt
.5 lbs carapils (dextrine)
.5 lbs flaked barley

The adjuncts and specialty malts add up to 2.5 lbs, so I'll mash 2 lbs of the base malt (2-row) along with the specialty grains to get my 4.5 lbs total. The other 9 lbs will be converted to extract: 9 x .75 = 6.75 lbs light LME or 5.40 lbs light DME.

Then you have to figure out your water volumes. I start with 3 gallons in my boil pot, so I want combined mash/sparge volumes to equal that (plus 1/2 to 3/4 of a quart to offset grain absorption). A good water/grist ratio is 1.3 quarts per pound so I'll mash with about 6 quarts of water for an hour, then sparge the grain bag in the boil kettle with 6.75 quarts of water. After removing the bag, pour the mash runnings from the cooler into the pot with the sparge water and I should have my 3 gallons of wort. This is when I usually start my boil.

I prefer to add all the extract in the last 10 minutes or so for a number of reasons. First, it keeps the color lighter and more like the original recipe. Second, it gives me a normal gravity boil for good bittering hops utilization. It also gives the wort a chance to boil down by a couple of quarts, leaving more room in the pot for the extract and reducing my chance of a boilover. When done this way, I can use the original hops schedule from the recipe without accounting for the partial boil. Of course if you're doing a full boil, you may do this differently.

Thanks, i had a feeling specialty grains were treated differently, but i needed confirmation so that makes sense, so given i am relatively new to this partial mash thing, can someone gimme a list of the most common base malts and what tstyles they would eb used in, im also gonna go look at past extract w/grain recipies and see what i can glean from them, GREAT post man

It's the grain that there's the most of listed in the recipe.

2 row, 6 row, pale, pilsner........those are the usual suspects.

fair enough, i have seen alot of 2 row and pale, pilsner makes snese, never seen any 6 rom, i guess i can check the bjcp guide too and its list of grains by style!