Need help lowering ABV

What are you trying to make?

 

I just brewed up a chocolate pumpkin porter recently heres the recipe

http://ryanbrews.blogspot.com/2012/10/pumpkin-porter.html

 

As a ballpark, you could simply reduce all of the malts and pumpkin by 30%.

 

Is scale all of the recipe including hops and spices as well as grains.

 

It's not quite that simple. Building a recipe is a juggling act with sweetness, bitterness, and body. There's also a balance of maltiness, hops, spices, and whatever other flavor components are being added. Touch any of these characters and the rest are thrown off balance. Any adjustments to a recipe like this for the purpose you stated would be a crap shoot, at best. It will take some insight into what each ingredient brings to the party (aka experience), as well as some trial and error. I don't sense that's what you're looking for. I would suggest finding another similar recipe for a Chocolate Pumpkin Porter that is not imperial. Better yet (internet recipes tend to not have stellar reputations), talk it up at your brew club (you belong to a club, right?) and get suggestions from those who have done something similar.

I would also suggest maybe a collaborative brew with a more experienced brewer. Novice is not a good place to start playing with things like pumpkin. It's not particularly difficult, but it helps to know what's going on in the mash to do it effectively. I'm also a little concerned with using 4 lbs of pumpkin in a mash this small. But I'm no expert.

 

The hops and spice don't effect gravity, but you want to maintain the BU:GU ratio the original recipe intended for (unless you want to change that).

 

Hop utilization will increase with the lower gravity. You'll end up with increased bitterness unless you account for that. That's why I said it's not as simple as it initially seems. If you're really, really in love with the recipe, the safest approach is to brew it as is, then add water at the end of the boil to get the gravity down where you want it. But it's still likely to be disappointing.

 

In general, taking a good recipe and simply cutting fermentables back drastically, without changing hops, spices, etc. is not going to make a good beer. I would echo mikehartigan's recommendations. Or at the very least, I would cut back everything (except water) proportionally, and then ask for comments on the resulting recipe.

 

I would do the IBU calculation on this. It's likely to be on the high side. As I said, hop utilization goes up as the gravity of the wort goes down. Your BU:GU ratio will be affected by this. A 25% reduction in gravity may require a 40% reduction in the 60 minute hop addition, for example. Otherwise, the beer is likely to be too bitter (40% is only an illustration - you need to do the calculation to get it right). And I'm still concerned about trying to mash 3 lb pumpkin with less than 2 lb of grain.

 

add 1 lb of sugar to dilute the malts.

 

all that's going to do is add more fermentables. the OP is trying to lower the %ABV, and adding sugar is just going to give the yeast more material to turn into alcohol. usually sugar is added in place of other malts to provide the same OG without as much residual sugar that is perceived in the body, so a "lighter" beer made with sugar still has roughly the same %ABV as its counterpart made with the corresponding amount of grain.

 

i was hoping someone would have picked up on the joke. i should have said "10 lbs of sugar"

 

Miss your volumes on the high side.

 

yeah i thought you were kidding but didnt want to be a jerk in case you werent...

 

I was gonna say pitch brett into the secondary...