Does topping off really not affect the quality of the beer?

[Lost in the Rye]

So it's common practice in extract brewing to do half of the volume in the boil and then top off with water at the end. And shake. A lot. I was even told by one guy that I could boil 1/4th and top off 3/4ths. But last time I did just a 2.5 gallon batch and did a full boil. And I think it's one of the best beers I've made. All the other process was the same, so that leads me to think... perhaps topping off really does affect the quality of the beer.

[Tankard]

If my evaporation rate is too low and I only end up with 4.50 gallons in the carboy, I will top it off. I haven't really suffered any negative effects from doing this, although I've only had to do this twice.

I've never done a full boil extract batch, so I'm not sure if it really increases the quality of the beer or not compared to partial boils. I do know that the hops are better utilized in a full boil, so you can use less of them to get the same result.

[mr x]

Well, this is an interesting question. I just finished a Southern English Brown which I topped up (just 2 gallons) in order to get a 15 gallon batch out of my 10 gallon system.

I've got an article from BYO on diluting with water, once I find it again, I'll post the link.

http://www.byo.com/stories/techniques/a ... techniques

[Lost in the Rye]

Interesting article. The thing I always seem to have trouble with is the initial mixing. I've tried multiple methodologies of adding the water vs adding the wort. And I've shaken the fermentor quite quite well (one time it even slipped and went sailing about 5 feet before hitting the ground forcefully - thank god for better bottles), but the gravity never reads correctly. And when I topped off a 5 gallon batch that was then split in 2 (so I could do 2.5 gallons lagered and 2.5 gallons steamed) the two halves did not come out equal strength. Which made me think that not having it correctly mixed might affect the fermentation somehow. I know the fermenting does mix it up as the final gravity is correct. But maybe, just maybe it affects the flavour?

[mordantly]

i think the benefits of late extract/partial boils is most greatly utilized when the brewer does not have the capability to boil 6 or 11 gallons in one vessel. personally, i started with a keggle so no volume is a hindrance. i suspect that the greatest fear of folks (myself included) is that a top-off has the potential to introduce bacterium, chloramines, off-flavors, etc that a full-boil avoids. as to the mixing, i venture one would have to use a wine degasser for instance to fully mix the liquids. if not mixed fully but still in the same fermenter as a whole, how could the flavor change? everything is still in there and the additional mixing due to transfer can only be good-news-gators?

[mr x]

I can tell you that my SEB turned out great.

[Tankard]

Nice. Thinking about doing that style next... I've read that the BCS recipe is a good one to try.

[mr x]

I like it. Very easy to drink quite a few without being hammered.