Understanding boil and Hops

[Dadux]

So i have read quite a lot in a rather short time like all new ppl that go into brewing and i still have some basic doubtd about bpiling and hops additions i was hoping someone could help me with.

I know how its traditionally made but im doing biab now and im not sure i have to boil for 1h...my volume is as i need. I get that you have to boil to sterilize and hops but is there any benefit on longer boils?

My second point is hops. Bittering addition flavour adittion and aroma. Yes. I get that. I also get that low AA hops are not good for bittering. But what about the other way around? I have some 19.6% AA polaris hops and i like the aroma they give. Is there any reason i cant add 15 grams to my 14l of beer for dry hopping? Is it gonna add any bitterness or off flavours?
Also hops added at the start of the boil do they lose their flavour and aroma? Or can i just boil for 20m and add a bigger charge of hops just once if it fits my target IBU? So like mix bittering and flavour and aroma addition all in one, boiled for less time, so i get the same ibu.

And if i donr get to boil? Ive read that mash temps give 30% of the ibus normally obtained at boiling temp. Does that mean i can add my bittering hops there?

Lastly, the flavour hops confuse me. They are in the middle. Hoe do they give flavour? The more volatile aroma compounds are boiled while some are retained? Or how does this work? If so, then do aroma hops give flavour just as well and i could add more aroma hops and forgo the flavour one? Or add more bittering hops later to retain some flavour.


Would appreciate any insight you can give me on the topic.

 

[McGarnigle]

I also get that low AA hops are not good for bittering.

They're more expensive for bittering, but not bad for it. Some people like using nothing but noble hops in certain recipes, despite their usually being low AA.

But what about the other way around? I have some 19.6% AA polaris hops

I don't know Polaris. There are some high AA hops that work for aroma and possibly flavor.

Also hops added at the start of the boil do they lose their flavour and aroma? Or can i just boil for 20m and add a bigger charge of hops just once if it fits my target IBU?

You can definitely do this. The shorter boil will maintain more flavor.

Lastly, the flavour hops confuse me. They are in the middle. Hoe do they give flavour?

They aren't really in the middle, but close to the end (~5-15 minutes). Aroma affects our sense of taste, so aroma hops will impact flavor. But I'm not sure I'd forego late hop entirely and just dry hop.

 

[ircbrewing]

I get that you have to boil to sterilize and hops but is there any benefit on longer boils?

I wouldn't boil hops more than an hour. There is a point where you will extract tannins which you don't really want.

 

[marjen]

Basically hop added at beginning of boil will give bitterness (IBU). For this you want to use something like columbus or CTZ. they are know as being bitterness hops. Also a lot of people are starting to use a hop shot instead, which is a liquid form that will give you the bitterness but leave less hop matter in the beer.

For flavor/aroma you want to add hops after you shut off your flame. Some people do them right at flame out, some wait until it reaches a certain temp like say 160 or 170 degrees to add them. For this stage you want hops that have the flavor profile you are looking for. flameout/whirlpool tends to add more flavor than aroma but will add to both profiles.

Finally is the dry hop in the fermenter. This will add aroma. But with aroma will come flavors a these sense often work together. Depending on the style of beer these can be added anywhere from pitch to a week or more out. Also about will vary widely from an ounce or 2 in a pale ale to 1/2 pound or more for a NE IPA.

Hope this helps a little.