kettle size question

I just pitched the yeast on my first beer a few days ago. I'm using a cheap Mr. Beer Kit gifted to me over the holidays, but I intend to get my own set-up for my next batch. If I plan to brew 2.5 gallon batches on my kitchen stove, would getting a 10-gallon brew kettle have any issues, such as condensation or possibly issues related to contact surface area? (I thought the 10-gallon size might be good in case I ever decide to do regular 5-gallon batches, but I don't drink that much, and I figure I wouldn't be able to brew as often doing 10-gallon batches, hence my leanings toward the 2.5-gallon size for batches.)

A future thanks to any who oblige!

If your doing extract brewing such as the Mr. Beer kit, extract cans or kits usually come with enough ingredients to brew 5 gallons. They also usually call for you to make a partial wort where you boil (this varies) 2 to 3 gallons in a pot and then transfer it to the primary which would contain the remaining 2 or 3 gallons to make the full 5 gallons of wort. You could cook up the whole 5 gallons with the kits if you had the vessel to do so. I get away with a 5 gallon pot because I usually make a 3 gallon wart and add it to 2 gallons of water in the primary.

If you were going all grain then you want the bigger pot as you would be boiling the entire 5 or more gallons of wart. Also if you get more then 5 gallons of wart you wouldn't have the room to add it to the pot and that would be very sad.

Are you planning on brewing 2.5 gallon batches because your going to use the Mr Beer container to ferment? I have a Mr. Beer container that I use to hold starsan and a blow off tube from my primary. I noticed 4 cuts in the top of the container where the lid screws on. I assume this is so the co2 has a place to escape, but it's not an airlock just a simple opening. All I think when I look at it is that air can penetrate the container.

Hope this helps

Thanks for the reply, dirtyjerz!

This will be my only batch with the Mr. Beer Kit. I am looking to buy my own gear very soon, but is a 10-gallon pot overkill for 2.5-gallon batches? (Would the condensation and/or surface area for a 2.5-gallon batch in a 10-gallon pot have a negative effect on the beer?)

I don't think it's a problem. After boiling the water you really should not have a cover on the pot being boil over will happen to quick for you to notice. Without the cover there's not much condensation as it gets cooked off as steam. I think the boil off ratio is 1 gallon per hour. So if your boiling your wart for 60 mins you would loose close to 1 gallon of (water which is now wart). I'm sure one of the guys or ladies who have been here for a long time can answer better.