user219: It really seems like homebrewing is a subset of beer.  It seems like the two should be contained in the same q&a site. 
What is the rational for creating two separate sites?
EDIT: This may be relevant to the discussion: the impetus for asking this question was posting this question on beer.se: https://alcohol.stackexchange.com/questions/358/what-ingredients-would-be-most-appropriate-to-prototype-new-flavors-in-a-randall?noredirect=1#comment371_358  The overlap between beer and homebrewing looks significant to me..

user39: This has been answered in a couple of places, namely in a comment, but I'll go ahead and give it a go.
Mission 
Homebrew has a pretty specific mission and vision. To support home brewers in the brewing of their own beer. To do that they do take on a variety of topics around the beer industry, tasting, ingredients etc.
However, the scope of this site is broader and more expansive. It includes large scale production, excludes super small scale production and generally is more focused on the consumption of beer rather than production.
Audience
This is where the real differences lie. While there is likely a good bit of audience overlap (probably all homebrewers are beer drinkers), Home brewers are a subset of all beer drinkers. This site is intended to appeal to the superset of beer drinkers.
Conclusion
The only real issue here is the ordering of the site's beginnings. Typically how site parentage would work would be that the larger audience site would be the first, and then the separate interest group would splinter. In this case the separate interest group already has their own site with their own question set.
There are a couple of interesting questions here on meta that address this further: 

Is Homebrewing on topic?
What should we do when a question already has an answer on the Homebrewing site?

And lastly, I'd like to point back to an instance where I had many of the same thoughts I've seen re: homebrewing with another set of sites that I was involved in. The Sport.SE/Fitness.se meta crisis.

Sport.se and Fitness.se should be combined

Shog set me straight here, and I've come to see his way of thinking about these things. It's worth a look back at what was said there to inform any future discussions here.

user80: I'm in the "No" camp, and I think Wax Eagle answered pretty well.  I'd just like to expand on the audience point a bit, though:
Although H.SE and B.SE have very similar audiences right now, they'll probably diverge later.
To put it another way, the people likely to commit to both sites are pretty similar, but the people likely to visit each site is significantly different.  The people who are interested in beer enough to go out and help found a community like B.SE are far more likely to brew than the average mild beer enthusiast.
As such, I predict that we'll get more and more non-brewers as we exist public beta.  Keeping the sites separate will serve those people better than a combined one.

user60: I tend to agree with you. I will be evaluating the private beta of "Beer SE" soon, and this is what has become evident to me as I watch this site develop:
My Beer SE Evaluation
The cross-cultural interests between "Homebrew SE" and "Beer SE" have way more overlap than I would have anticipated. I am not typically an advocate for combining producers and end users, but in this case, there is simply too much overlap of interests — not necessarily physical audiences, but interests — to ignore.
Hypothetically, if we were to remove the "brewing-related questions" from Beer SE (I'm not suggesting that), this site would become one big snooze fest fast. After I figure out what temperature to keep my beer… and how to keep it going skunky, just about the only interesting questions left are those that DO veer into what goes behind the brewing process. The deeper "consumers" here are asking about the "artisanship"… and that's the best part of this site.
It makes sense, really. When there's a fervent appreciation for a subject (at least food/drink space), the more-engaged experts almost have to delve behind the scenes to study what separates good brews from bad; to understand the parameters that go into what they're "appreciating." 
You don't have to be a literal "brewer/craftsman" to have an implicit interest in the subject. Many of the beer enthusiasts here are curious about the craft — you almost have to, to appreciate the subject — and that's why they are asking about it here. And of course the craftsmen need to know what makes a good beer … so there's a lot of cross-cultural interests here, whether you an actual, literal "home brewer" not. 
It simply makes sense to combine these subjects. While the brewers and consumers are not physically the same exact audience, they do largely seem to have the same range of interests… and questions. Essentially, the scope of these two sites overlap considerably; much more than I would have anticipated.

Put them back together. They will be stronger in combining their expertise; stronger for sharing their mutual interests and appreciation for the subject.

219: <p>It really seems like homebrewing is a subset of beer.  It seems like the two should be contained in the same q&amp;a site. </p>

<p>What is the rational for creating two separate sites?</p>

<p><strong>EDIT</strong>: This may be relevant to the discussion: the impetus for asking this question was posting this question on beer.se: <a href="https://alcohol.stackexchange.com/questions/358/what-ingredients-would-be-most-appropriate-to-prototype-new-flavors-in-a-randall?noredirect=1#comment371_358">https://alcohol.stackexchange.com/questions/358/what-ingredients-would-be-most-appropriate-to-prototype-new-flavors-in-a-randall?noredirect=1#comment371_358</a>  The overlap between beer and homebrewing looks significant to me..</p>
 39: <p>This has been answered in a couple of places, namely in a comment, but I'll go ahead and give it a go.</p>

<p><strong>Mission</strong> </p>

<p>Homebrew has a pretty specific mission and vision. To support home brewers in the brewing of their own beer. To do that they do take on a variety of topics around the beer industry, tasting, ingredients etc.</p>

<p>However, the scope of this site is broader and more expansive. It includes large scale production, excludes super small scale production and generally is more focused on the <em>consumption</em> of beer rather than production.</p>

<p><strong>Audience</strong></p>

<p>This is where the real differences lie. While there is likely <em>a good bit</em> of audience overlap (probably all homebrewers are beer drinkers), Home brewers are a <em>subset</em> of all beer drinkers. This site is intended to appeal to the superset of beer drinkers.</p>

<p><strong>Conclusion</strong></p>

<p>The only real issue here is the ordering of the site's beginnings. Typically how site parentage would work would be that the larger audience site would be the first, and then the separate interest group would splinter. In this case the separate interest group already has their own site with their own question set.</p>

<p>There are a couple of interesting questions here on meta that address this further: </p>

<ul>
<li><p><a href="https://alcohol.meta.stackexchange.com/questions/1/is-homebrewing-on-topic">Is Homebrewing on topic?</a></p></li>
<li><p><a href="https://alcohol.meta.stackexchange.com/questions/4/what-should-we-do-when-a-question-already-has-an-answer-on-the-homebrewing-site">What should we do when a question already has an answer on the Homebrewing site?</a></p></li>
</ul>

<p>And lastly, I'd like to point back to an instance where I had many of the same thoughts I've seen re: homebrewing with another set of sites that I was involved in. The Sport.SE/Fitness.se meta crisis.</p>

<ul>
<li><a href="https://sports.meta.stackexchange.com/q/96/6">Sport.se and Fitness.se should be combined</a></li>
</ul>

<p>Shog set me straight here, and I've come to see his way of thinking about these things. It's worth a look back at what was said there to inform any future discussions here.</p>
 80: <p>I'm in the "No" camp, and I think Wax Eagle answered pretty well.  I'd just like to expand on the audience point a bit, though:</p>

<p><strong>Although H.SE and B.SE have very similar audiences right now, they'll probably diverge later</strong>.</p>

<p>To put it another way, the people likely to commit to both sites are pretty similar, but the people likely to <em>visit</em> each site is significantly different.  The people who are interested in beer enough to go out and help found a community like B.SE are far more likely to brew than the average mild beer enthusiast.</p>

<p>As such, I predict that we'll get more and more non-brewers as we exist public beta.  Keeping the sites separate will serve those people better than a combined one.</p>
 60: <p>I tend to agree with you. I will be evaluating the private beta of "Beer SE" soon, and this is what has become evident to me as I watch this site develop:</p>

<p><strong>My Beer SE Evaluation</strong></p>

<p>The cross-cultural interests between "Homebrew SE" and "Beer SE" have way more overlap than I would have anticipated. I am <em>not</em> typically an advocate for combining producers and end users, but in this case, there is simply too much overlap of interests &mdash; not necessarily physical audiences, but <em>interests</em> &mdash; to ignore.</p>

<p>Hypothetically, if we were to remove the "brewing-related questions" from Beer SE (I'm not suggesting that), this site would become one big snooze fest fast. After I figure out what temperature to keep my beer&hellip; and how to keep it going skunky, just about the only <em>interesting</em> questions left are those that DO veer into what goes behind the brewing process. The deeper "consumers" here are asking about the "artisanship"&hellip; and that's the <em>best</em> part of this site.</p>

<p>It makes sense, really. When there's a fervent appreciation for a subject (at least food/drink space), the <strong>more-engaged experts almost <em>have</em> to delve behind the scenes</strong> to study what separates good brews from bad; to understand the parameters that go into what they're "appreciating." </p>

<p><strong>You don't have to be a literal "brewer/craftsman" to have an implicit interest in the subject.</strong> Many of the beer enthusiasts here are curious about the craft &mdash; you almost <em>have</em> to, to appreciate the subject &mdash; and that's why they are asking about it here. And of course the craftsmen need to know what makes a good beer <strong>&hellip;</strong> so there's a lot of cross-cultural interests here, whether you an actual, literal "home brewer" not. </p>

<p>It simply makes sense to combine these subjects. While the brewers and consumers are not physically the same exact audience, they <strong><em>do</em></strong> largely seem to have the same range of interests&hellip; and questions. Essentially, the scope of these two sites overlap considerably; much more than I would have anticipated.</p>

<p><img src="https://i.stack.imgur.com/LtPf9.png" alt="enter image description here"></p>

<p>Put them back together. They will be stronger in combining their expertise; stronger for sharing their mutual interests and appreciation for the subject.</p>
