Quick question on big beers

I am brainstorming my first truly big beer. Made a couple 9%-10%, but nothing huge.
I see a lot of big beer recipes add a bunch of dextrose or honey or candi sugar. My question is why add SO MUCH simple sugar?
Why not mash to result in a large volume, then boil all the way down to a highly concentrated, smaller volume beer? Sure you may boil for 3 hours or more, but why not? No babysitting the fermenter, it's all a waiting game.

If you build a fairly large 10 gallon beer, then boil the extra 5 gallons off, wouldn't the result be a really big 5 gallon? Just looking for a sanity check here. I am obviously missing something...

Simple sugars make for a dryer beer. So if you are doing a huge DIPA and don't want to chew the malt, add come simple sugars so it doesn't feel like a stout or barleywine.

I am not understanding your question about mashing a bigger volume for bigger beers. If you mash more grains, you get more sugar, which makes higher ABV%. So mashing 20 pounds of grain at 70-80% eff will get you 12-14% beer. You still mash with 1.25-1.5 qts of water to grain ratio, but sparge with less water. Think of it like this:

You are always trying to get the sugar out of the grain. Once the sugar is gone, it's gone. No matter how much water you add after that. If you use too much water, your pH gets too low ad you'll have other problems.

I hope that answers your question a little......

Yep. Besides big IPA's, Belgian tripels and golden strong ales are another prime example. You want that light body and mouthfeel in a relatively high ABV beer.

25lbs 2row 1130 OG est. FG 1027 ABV 14%

10lb Dextrose 1092 OG est. FG 098 ABV 15%

You can do an all malt big beer, it will just be like syrup. Or use some sugar to dry it out to be more of a balanced mouth feel.

No to mention the stress of the yeast trying to go from 1130 to FG. When you can start at like 1070 ferment down, add sugars, slowly in a schedule to get a healthier more controlled fermentation.

Sugar is to thin the beer out. As mentioned, dryer beers are better for particular styles, i.e. DIPA, Belgian everything. Some big beers do not use simple sugars. If you looked at a clone of BCBS (15% ABV), for instance, it would use no simple sugars because you want the body to be thick and what some might consider syrupy.

The drier beer is what I thought the reason was. Thanks everyone.

When I say mash a higher volume, I mean mash "like" you are going to brew ten gallons of beer. Then, boil the wort down to five gallons. In a sense, concentrating it.

The mouthfeel makes sense. It would be very syrupy.

A longer boil will also caramelize more sugars and this doesn't work with all styles--especially since caramel can be an off flavor for some or even appear to be other off flavors (like diacetyl). Many of these caramelized sugars also become unfermentable, which will increase final sweetness.

Your post makes it sound as if such additions are not as "pure" as using grain alone or are somehow cheating, but: 1) Most homebrewers do not feel compelled to follow the Reinheitzgebot; 2) Many homebrewers like to use an assortment of techniques and ingredients to make the best beer; 3) Using such sugars has a very long and even refined historical precedent in beer making--some historical beers are not possible without it.

Besides, these sugars often make flavor contributions to the beer besides fermentable sugars. Pull a high gravity beer and then another regular beer. Up the gravity on the lower smaller beer with molasses, candi sugar or honey to match the gravity of the big beer. You will not end up with two matching beers. Neither will you simply have one dryer version of the other. You will have two very different beers with very different flavor profiles, color, etc. Depending on when in the boil the sugars are added you can also have very different IBU's.

We constantly tweak our beers--more grain or added sugars are just another way to do this.

Big beers are my favorite to brew and I have some (like my Wee Heavy) that use grain alone for gravity, then others (like my Old Ale or my Winter Warmer) that I use various sources of sugars.

If you want to taste what a ridiculously long boil tastes like, get Green Flash's Barleywine. I believe they do a 4 hour boil and it tastes kinda weird with melanoidins - I'm not a fan.