Late Addition of Extract During the Boil...Why?

Hey guys,

While my 1st batch is almost ready to bottle I’m looking around for ideas for my 2nd one.

I’m thinking about doing a stout or porter, and both extract kits call for a late addition (15 minutes left in the boil) of some of the liquid extract.  I was just curious as to what this does vs. boiling all of the extract for 60 minutes?  Does boiling the extract syrup different amount of times affect the taste and potential OG?

It affects the hop utilization rate.  A higher gravity boil will provide less hop utilization.

You’ll also get less darkening of the wort (apparently it’s not technically carmelization…) by adding the extract late.

The longer you boil the extract the darker it will get.

Not an issue with a stout or porter, but if you’re doing a lager or anything light it will have an impact.

Oh interesting, i had it backwards. So for an IPA you want a late add for the malt?

Not exactly.  Late additions really only come into play when you’re dealing with less than a full boil.  If, say, you’re doing a 3 gallon boil of a 6 gallon batch (topping off later to get to 6), then the gravity of your boil would be twice what is expected if all the fermentables are present.  With gravity that much different than expected, your hop utilization calculations will be all wrong.  If, instead, you only added half your fermentables to the 3 gallon boil, then the gravity will be right where expected.  Add the remaing half of your fermentables late and then, post-boil, top up with 3 more gallons and again, you’re gravity is right where it should be.

If you’re doing a full boil, then it all becomes moot as your gravities are going to be correct throughout the process.

Does it really become moot with a full volume boil? Looking at hop utilization vs gravity, there could still be benefits in waiting to add a portion of extract until the end of the boil in order to more fully utilize hops. Don’t know this from experience at all, but it would seem that if you’re doing a high gravity, highly hopped beer you could take advantage of that. But then maybe I’m way off base. My knowledge is still mostly book knowledge, with only three real brews under my belt so far.

The point I was addressing was that not doing a full volume boil will mess up your hop calculations.  That is, if your recipe uses a hop schedule that results in, say, 40 IBU but you only do a partial boil, your IBUs won’t end up at 40.  Likewise, if you do a full boil with late extract addition, your IBUs still won’t end up at 40 (probably off in the other direction but off nonetheless).

If you’re just trying to maximize hop utilization then yes, the extract late full volume boil could increase it.  Although I’m sure there are gravity and utilization limitations that’ll come into play at some point.

Oh, it looks like you’re new to the forum, WELCOME!

Thanks!

Yeah, that is a good point, if you are trying to nail a specific IBU, it would require different calculations if you don’t have all of your extract in the full volume boil.

I guess that depends upon whether you are scorching your extract on the bottom of your pot. :slight_smile:

I thought malt extracts need to be boiled for an hour.  Is that not the case?

Nope, just for 10-15 minutes to sanitize. They’ve already been through the thermal ringer once.

Actually the cans don’t really need to be sanitized at all.  You can use some of the pre-hopped LME to make a no-boil extract beer.

DME on the other hand does need to be boiled because in does not undergo the sanitary canning process.