If i'm not mistaken, i think he just said commercial brewing, not necessarily brewpub. BUT, from what i understand, that'd be more of an uphill climb since a brewpub's food actually pays for the brewery portion. With a micro, the only income you're getting is from the beer, putting your back against the wall in the beginning.
First, the OP wrote:
We are opening a bar and planning on getting the license to brew beer there.
That scans like "brewpub" to me.
Anyhow, what you say is kind of true; based on my experience, it's not exactly 100% true, but close.
The micro for which I used to work had for years a small pub attached that was a good revenue source for the brewery (there were some months where it was a positive gold mine). But it was never the food that paid for anything. Let's do the arithmetic, shall we?
When a pint of your beer costs the customer $4.00, and it costs you (including overhead, wages, taxes, etc.) $0.24 to bring it to the customer, that $3.76 clear profit, or 94% profit margin.
When a plate of food costs the customer $10.00 and costs you $2.50, that's $7.50 clear, or a 25% cost on food. (25% food cost is best-case. You're lucky to get below 35% in the kitchen.)
You actually make more money on beer than food. And since you get far more beer fans in a brewpub or brewery bar than foodies, it's pretty straightforward that the food, while important to retaining customers, doesn't have to get people in the door. It certainly doesn't pay for the brewery. The beer does.
Add in off-premise sales - i.e., bottled or kegged product, not just growlers - and suddenly you've got a whole new revenue stream.
Anyway, the beer is the draw. The service and the food keep the beer geek's family coming back. And repeat custom is what keeps a restaurant open.
Now, addressing the back being against the wall. The only solution for that is being well capitalized. Too many breweries were started by brewers in the Microbrewery Revolution. Those breweries no longer exist. Those started by businessmen (or a partnership between business and beer) still exist, and in most cases are thriving.
Brewers started breweries on a shoestring budget, with old milk-processing equipment, no clearly-designated business goal or model, no core brands that set them apart from the herd, no marketing plan, and (most unhappily) precious little capital to see them through the tough times.
Businessmen started breweries rightly thinking of the beer as a product which needed to be sold in a tough market. They knew to find a niche and market their product into that niche. And they knew to have a cash reserve for when times got tight. Hell, the most successful craft brewer in America didn't even have an actual brewery until years after he started his business!
This is especially important in brewpubs. You must never forget that they're a restaurant first and a brewery second. They have a built-in niche in that the customer can get fresh craft beer made on-premise. But you still have to market the place, you still have to have enough cash laid by to make payroll if things get tight (or to buy new equipment), etc.
The long and short of it is: Brewing is
business. Brewers, like most artists, generally make lousy businessmen. If you want to make beer for a living, your sanity is far safer working for someone else.
Cheers,
Bob