Realistically, How Big of a Beer can I make?

I have a Coleman 36q Xtreme cooler that I plan on converting to mash in.
I've seen the "rackers" calculater and someone posted a chart. Rackers said my tun can handle up to 23lbs of grain, and the chart said my tun can handle a 5 gallon batch with an OG of 1.13 I think.

I don't intend on making really big beers all the time, especially since I only have a 7.5 gallon kettle... but I would like to make some 8-9% IPA's and stouts.

I don't intend on making 10 gallon batches, so is the tun I have sufficient enough to make 5 gallons batches of basically anything? Or will I have some limitations?

OG of 1.13 is starting to get into the barley wine category.
So yes, you can probably brew anything your heart desires by mashing up to 23 lbs. of grain. I just brewed a 1.082 tripel with 14 lbs of grain (+ 2lbs DME) which should yield a 8-9 percent beer.

I have a 40q igloo and I make 5-6 gallon batches of 8% IPA and 7-8% stouts all the time, with great efficiency, that's about 14ish#'s of grist. If I only had a 7.5 g kettle instead of my 10 gal kettle I would be in trouble though. For me, to finish with 5.5-6 gallons I need 8 gal starting boils. You would have a hard time controlling 7 gallons of hard boiling first 7 minutes of the boil in your kettle. That said you would have no trouble scaling down your recipe for a 4 gallon final and starting with 6.5 gallons, that should give you ample headroom in the kettle for a good boil that shouldn't be too much trouble. If you scale down to 4 you would only have like 12# of grist to make a strong IPA.

So right now your kettle is more limiting than your tun

^ Good points. But when I was using a 7.5 gallon brew pot, I only needed a 6.5 gallon pre-boil volume. It wasn't until I started using a keggle that I needed about 7.5 - 7.9 gallons. Much more surface area in the keggle. Of course I no-sparge, so I start with the total boil volume.

I christened my newly build 10gal round rubbermaid cooler with a RIS. It turned out to be 1.12OG. Should be about 11-12% if the yeast can handle it. About 25lbs of grain, 2-10 gal pots and two burners. I sparged until both pots had a good 8 gallons in them then boiled...and boiled...and boiled until it fit into 1 pot. Then boiled until it reached my normal starting point and started my 60 min boil\hops additions. You really need to sparge a lot and get a lot of wort to get the efficiency out of the grains meaning a lot of boiling to get it down to 5 gal.

You can also do a double mash, which helps to keep the boil volume down (with a little hit to efficiency). Just divide your grain in half, mash the first half (thick), drain, do a small sparge, and then use that wort to mash-in the remaining grain. Sparge, etc. I made a beer this way that ended up at 13% ABV. My boil started at only 7 gal for a 5 gal. batch.

thats all great know. I figured that the 36q xtreme would be plenty big enough for my current needs. But naturally when I bought it after some looking around, I was questioning it's capacity.

Now I guess I need to scrounge up a bigger kettle or find an empty keg. First all grain day is coming up quickly on memorial day weekend. I've been studying and reading for months, I'm ready to knock this one out of the park.... or at least hit a dribbler back to mound.

If it's your first AG you dont need to start big. Just start with an easy recipes to get your process down. Maybe an EdWort Haus Pale Ale...

If you try to go big from the beginning you may be setting yourself up for an epic failure...

BTW, where in Ohio are you?

oh no I don't intend on making a big beer for a few batches yet. And funny you mention edwort's haus pale ale, as that will be my first all grain batch. Before I convert the cooler I have, I just want to make sure it'll eventually be able to handle a big beer when I'm ready. I'm working up to bigger and better brewing, I've made three good extract batches and I'm ready for the next step. I want to make beers in the 7% abv range, that's what I prefer.

I live in New Riegel, about 1 hr 15min straight north of you about 4 miles off 23. Is there a decent home brew store your way? I have to drive up to BG for my supplies.

Ahh...I gotcha. Sounds like you got everything under control then.

Good luck!