Late extract and hops question.

So if I choose to do a late extract addition, say with 30 minutes left in the boil, but the bittering hops obviously need to be added before, all I have boiling is hops and water? Thats ok, right?

That's a good question that I'd like to know the answer to as well. I always assumed that late extract addition meant that you'd add a part of the extract up front, then add the second part "late" in the boil (not all at once late in the boil). But look at my number of posts: what the hell do I know...?

I can't find the BYO article on this but here is another from beersmith Better Beer with Late Malt Extract Additions

You need to add some of the extract at the beginning, bring back to a boil, and then start your hop schedule. I don't know why technically, but I believe that proper utilization of the hops requires some extract. Most people add half at the beginning and half either with 10-15 minutes remaining, or at flame-out waiting 10 minutes before cooling to allow the extract to pasturize. But you could probably get away with less than half depending on your boil size and the total amount of extract you are using.

Add 25-30% of your extract up front. Add the rest late (I usually do it @15minutes to go).

it's not necessary to be this exact about it, but the general idea with a late extract addition is to have a 'normal' gravity during most of the boil (ie, the same gravity you'd have if you were doing a full volume boil); so if you're doing a 5 gallon batch and will be ending the boil with 2.5 gallons (which you'd top up with 3.5 gallons of water); then you'd want to add half of your extract. if you're ending the boil with 1.5 gallons, then you'd add 30% of your extract; etc.

but like I said, you don't really need to be that exact; so anything from 25-50% in the beginning is probably fine.

What if you do a partial mash with 3ish lbs of grain. Should you still add some of the extract early or is the mash liquor enough?