Would I achieve a similar flavor by pulling a gallon or so of first runnings and boiling down to, say, 50% volume? (like some people do with wee heavies)
I do not believe these provide the same benefit.
I do love that technique, but I believe it provides some sweetness, and caramel notes. I think it is a much bigger flavor impact than decoction provides (which seems rather limited).
Not the same flavors in my opinion, but still a nice addition on beers that benefit from caramel-like flavors.
When you boil down the first runnings to the point it makes you scared, caramelization is happening at higher temps than boiling.
When you do a decoction, you are producing melanoidins at boiling temps, as the decoction is not boiled long enough or hard enough to concentrate. I don’t boil the decoctions too hard, as I don’t want scorching to happen.
Pressure cooker decoction, baby :) No constant stirring, no scorching
tell me more
Nope, not the same, even assuming that decoction adds flavor.
Ok thanks for the info. I won’t worry about it so there’s one less thing to screw up.
Some boiled down first runnings add great complexity to a Doppelbock. Don’t do it to a Pilsner, though.
Go to the eZymurgy archives and check out page 39 of the Mar/Apr 2010 issue. Jeff Renner did an article titled “Pseudo Decoction Mashing” that explains it.
Going to the NHC BJCP reception?
With a pressure cooked cereal mash you get to about 230f, and some caramelization but lots of melanoidin production. Mr. Renner is a good friend.
No, not making it to the NHC and yes, love his pressure cooker decoction method.
The cereal/decoction mash is in a pot, that goes into the pressure cooker. The pressure cooker has a false bottom and water under the false bottom. The goods never go over the steam temp, so no scorching, and no need to stir.
IIRC, Jeff has a 22 quart pressure cooker. Good size for a CAP cereal mash.
I’m noticing pressure cooker false bottoms have some holes in them…won’t grain fall through? I’m intrigued by this idea. I always seem to have a problem with decoctions where while I’m boiling the decoction, the main mash drops too much in temp and adding the decoction back doesn’t quite bring it up to the next rest temp. Maybe I’m boiling the decoction too long or something. I usually take most of the thick mash out for the decoction.
Some pictures from brewing a CAP at Jeff’s.
The cooker in action.
Loading the cereal mash in, this pot gets its lid put on, then the cooker lid goes on and is clamped.
guess I need a bigger pressure cooker :
mine is much smaller than that.
Mine is the Presto 23-quart and it’s plenty big enough…
Yeah, the one I have right now is only a 6qt or maybe 8. I imagine though that a big pressure cooker should be an easy purchase to justify. Especially as the garden starts to come in.
I’m sure we all know this, but I think it’s worth pointing out that the steam is under pressure and will be hotter than 212F. How hot depends on the pressure. Just to be clear. 
Already mentioned in reply 10.