Purpose of the boil after mashing?
 

OK, so during the grain mash the starches from the barley grain are converted to sugars and subsequently the wort is boiled for typically an hour.

Other than allowing added hops to provide some bittering and aroma, does the boil serve any chemical purpose, for example, does it change the composition of the sugars or is the boil merely done in brewing to blend or enhance the malt flavors?

I mostly brew using extracts but often I also mash in grains (e.g., PM brews) and this is mostly done in a separate pot which I then add to the extract boil.

My question is really; do I need to boil the separate grain mash for one hour if I will not be boiling the "extract sourced wort" for more than a few minutes?

Thx...

It's also nice that the boil kills off the bacteria living in your wort. Plus the protein coagulation during the hot break.

There's going to be some caramelization of the sugars, also the wort will become more concentrated, and it sterilizes the wort (although that probably only takes 5 minutes). Of course the addition of hops to the beer is an important part of brewing and boil time and wort gravity during boil will both affect the final bitterness of the beer as well as the aroma and flavor. Of course you could just use hop extract if you really wanted, but in my opinion that would take away some of the fun.

I think the angle he's going for is you could technically add a bit of extract to some water, boil that and the hops for 60 minutes while the minimash is mashing. You could then add that and the rest of the extract at the last 15 minutes. It could potentially save time for low IBU beers, but I'm guessing only about 30 total minutes. Your hop utilization would be pretty low though and you'd suffer pretty low efficiency on the mashed part of the wort.

Also just to clarify, during the mash, you should not be boiling. The range to mash is ~148-158°F. And the time period for the mash is important for conversion. True, you may not need an hour if you do an iodine test, but the hour is a safe period to ensure conversion without a test.

They also sell "no boil" beer making kits where you just add tap water to hopped extract stir it up and add yeast. Maybe a campden tablet or something to sterilize. So I guess you don't NEED to boil that much, but I sort of feel like the boil is the easiest part of the whole endeavor. After the hot break you can pretty much just sit back and have a beer and toss some hops in every once in a while

Yeh, Bobby B has the correct issue.

I usually don't boil the extract wort for more than 20 minutes or so. If I'm preparing a separate mini-mash from grains to be added to the "main" boil, I could save some time if this non-extract wort (e.g., the grain mash) does not have to be boiled for 1 hour.

Yeh, I'm mashing at around 150F only.

Time is $ and I'm trying to reduce kitchen time without cutting corners.

Thx...

You doing steeping grains for color and flavor or actual mashing for fermentables?

There are at least a couple things that a long (60 min or more) boil does:

Changes flavor, color, and fermentability through the formation of Maillard products (NOT caramelization - sorry, pet peeve).

Allows SMM (the DMS precursor) to vaporize and be driven out of solution. DMS is the "canned corn" flavor that sometimes can be tasted in beers that don't utilize a long boil, especially with pilsner malt.

You doing steeping grains for color and flavor or actual mashing for fermentables?

...for both color/flavor and fermentables. Isn't this question dependant upon how big your grain mash is compared to the extract and which grains you are using? Typically, I'll mash (steep) 2 or 3 lbs of grain for a 5 gallon match but sometimes, less.

..obviously, for the bigger mashes i'll use mostly a pale malt or light grain. If for color only I'll use less than 1 lbs. of specialty grain, for example.

Thx...