im doing a kit from aih, it comes with grain and extract. with that being said, i am confused with the 5 gallon issue and what way is best to get there.
Do you have a pot big enough for boiling the 5 gallons. If not the question is answered for you.
This isn't a question where one way has significant advantages but also significant costs and you stand at a cross-roads and must make a lifetime decision. Basically you need to cook up 5 gallons of wort and whichever way you do it, although having a few little coincidental tricks and advantages, really doesn't make much difference.
There are coincidental advantages to either way. Smaller boils are quicker to cool (see below). Bigger boils are simply closer to the natural concentrate and will feel more natural. But the choice you make will really be a matter of convenience and whatever works for you. I'd suggest boiling as close to a full boil (and over if possible) as you can. But if you can't no-one's going to ever notice.
if i do a 2.5 then add another 2.5g, wouldnt this cool the wort down to much to pitch the yeast?
Quite the opposite. It'll cool down the wort fast enough that you *can* pitch the yeast sooner.
You are cooling from 212 (very hot) to 70 and that takes time. If you are mixing with with a lot of top of water its a lot faster but it still takes time. Even if you boil away to a gallon and add 4 gallons of top-off water it will still take fifteen minutes or so to get down to 70.
Either way the concern is getting it down to 70 fast. It's almost *never* a concern that you'll get it down to cold.
And the top off water itself isn't too cold to pitch. although it is better to pitch the yeast in the correct range, pitching the yeast too cold isn't a big deal. It'll be a slow start but when it warms up it'll go in ernest. There are other issues that I don't really understand but none of them are capital offenses. And pitching at 60 is *great*. Pitching when the yeast is too hot is another story. Then you can (but it's not a certainty; nothing in brewing is a certainty) and probably will get off-flavors.
also in my garage, which is where i will be storing this, gets cold at night but warms up somewhat in the day, N.E penn climate. is this a big factor?
thanks in advance.
It can be. Especially the warming up during the day. How big a fluctuation? Temp control is a really simple way to fine tune. And way out there bad temps seems to be the thing (maybe the only thing) that can actually make otherwise good beer become bad beer. But beer brewing is supposed to be fun. My first few beers with poor temp control and pitch to high were all "pretty good" and "hey, not bad!" but my beers *with* very casual temp control are noticeably better. (Probably because of temp control; maybe I'm just getting better--- but probably the temp control).
I've *really* bought into the ice bath camp for my last four batches or so. (Fill a tub. Chill with ice bottles. Swap out roughly once a day.) A little goes a long way.