Pre first batch...

As long as your stove can boil 5 gallons (though a full-boil would actually require your stove to boil more than 5 gallons), there is no reason to use smaller equipment. The only thing I could think of is that a 10 gallon cooler mash-tun may not hold heat quite as well with so much dead-space( when doing 1 and 2.5 gallon batches), but I'm not sure of the physics behind heat loss.

Fermentor-wise, it may not be the best policy to do 1 or 2.5 gallon batches in a 5 gallon carboy/bucket, though 2-3 week primary fermentation may be fine with 2.5 gallons.

That said, full-boil 10 gallon batches are probably a little much for an electric stove.

 

There is at least one unknown variable here that can be important toward answering your questions. If you get a boil pot with a large diameter, it may straddle two burners on your stove and help to get a large batch up to a boil. However, if you get a pot this size and do a small batch, the liquid would be more shallow, and I think this would lead to easier scorching of the sugar.

There are probably other considerations that would create negatives for you to brew small batches in large batch equipment, and other posters may chime in with them. But the best way to find out is for you to try brewing a small batch with a recipe (a Pale Ale, for example) that uses relatively inexpensive ingredients, and then see what happens. Watch every step of the boil closely and keep very detailed notes to properly evaluate this 'experiment.' Good luck.

 

If starting with Extract, you can do full 5 gallon batches, just boil less volume and top off to the desired volume. I started using extract and only boiling 2-3 gallons and then topping off. Good practice to get a feel for all the steps before purchasing mash tun and other more specialized equipment.

I too at one point had crappy Apartment rules, they suck, don't even let you go 10' away from structure anymore.

 

I recently transitioned away from my electric stove, which was not capable of boiling 5 gallons. I will point out that maintaining a boil with 3 gallons in a pot large enough to boil 5+ gallons isn't any easier the boiling the larger quantity of water (it will take less time to start the boil though). My stove could bring 5 gallons to a boil in a 7 gallon pot, but once the lid was off, it couldn't maintain a boil. So if you have a pot large enough 5+ gallons, and the stove can handle it, there isn't much advantage to doing smaller batches and if the stove can't handle it you will likely need a smaller pot.

 

My point is boiling (maintaining the boil, not reaching it) 3 gallons (for a 2.5 gallon batch for example) in a 7 gallon pot takes the same amount of output (or near enough) from the stove as 6 gallons (for a 5 gallon batch). So you aren't gaining anything there unless you are using a pot which won't work when you try to step up to larger batches. The heat input required to maintain a boil will equal the cooling to ambient by the pot, which doesn't really depend on the amount of water in the pot. Most of the cooling at near boiling temperatures occurs due to evaporation at the surface of the water, which varies by diameter of the pot, not water level. That said it definitely takes longer to bring the larger quantity of water to a boil. I only mention this because my stove could not maintain a boil with my 7 gallon pot with only 3 or 4 gallons in it (though it did boil 2.5 gallons in a smaller pot). By the way, 7 gallons is really the absolute minimum for a 5 gallon batch (most around here will recommend bigger), because first you boil off about 1 gallon during brewing so you start with 6 or more gallons, and second you can't fill the pot to the brim, and then try to boil it, that will lead to a mess.

 

I do 3 gallon brews. I have 2 3gal carboys. I do plan on moving to 5gal soon. I also do all grain so don't feel like you have to go the extract route, although I have heard that extract is just as good. I've just never tried it. It yields about 28 beers.

 

You might look into a drop in style electric element that hangs on to the pot, I use one for my HL and sparg then boil with gas outside. It does well boiling the beer which i enjoyed doing in the basement but the wife dosen't like the smell of boiling hops.

 

If you get a smallish boil pot you'll find it will come in handy when you upgrade later to a larger one. The small can then be used to heat sparge water, etc. So it is a good choice for now and as an investment for later.

 

Barhoppin, I just disolved my 15 gal system to focus on smaller batches 3-5 gal, Keeps the tap handles rotating quicker for me. use a good brewing software and size don't matter you can scale any beer/batch. I like the three gall batches (initially 4 gallons but final to keg is 3) because a lot of times I can pitch a single tube/smack pack of yeast without having to do a starter. there are good deals on 3 gal kegs also out there they take up less space in the fridge as well and travel nicely.

 

check this out http://ep.yimg.com/ca/I/yhst-69536781200715_2270_89794411

 

my standard noob harping post...

fermentation temperature control. below 70F ambient, but 62 is my preference
yeast pitching temperature control. below 70F
fast cooling via wort chiller. pre-chiller needed if your tap water is warm
sanitation
full boils
KISS methodology and recipe formulation

everything else is secondary. if you haven't addressed all of these issues, you are less than ready to go.

 

Two things I can think of when I went from small batches to larger (only been doing since beginning of year):

1. I found I had an issue bringing 5 gallons to boil on a stove-top, which led me to less-than-ideal hot breaks doing all-grain.
2. I have fermented 3 gallon batches in a 6 gallon bucket, without noticing a loss in flavor. However, there were times the fermentation wasn't obvious (was guessing just not enough pressure built up to bubble the air lock, but the FG ended up right).

 

I have a 5gal cooler mash tun with false bottom, 4gal brew kettle, and 2 3gal carboys less than $200. I've only been brewing since January, but once I figured it out my setup is pretty efficient.