Our Story


Five brothers, Rob, Ed, Charlie, Jon and Paul, thought it might be a good idea to pull the family together and make some tasty beer.
We were looking for beer we love, the darker beers, good red’s, browns, porters and stouts. But there were just not enough of them around. We wanted to experiment too. What if we combined our Irish heritage and California creativity to create a really tasty brown porter, or a clever stout made with a wide variety of yeast strains, hop selection and malted barley’s now available? Sounds good!
Let’s do it.

With our big Irish family clan, we’ve got lots of siblings, nephews, nieces and cousins we can draw from for help and a few of them could use some work anyway. So in the spring of 2013, O’Sullivan Bros. Brewing Co. was formed. We needed a little help though, who knew anything about commercial brewing? Narry a one. So, it was decided we would send Ed to beer school. Ed signed up with UCSD’s Brewing program and quickly learned how to buckle down and study again. Ed was the logical candidate, not only having a love for well made craft beer and having a Biology degree from UCSD, but also having manufacturing experience and a strong finance background made him perfectly suited to understanding all the variables of commercial brewing. Let’s not forget, beer is science and making beer is a business.

While Ed attended brewing school, we set about raising a round of funding sufficient to build a small brewery. That task complete, we then began looking for a site. After looking and looking, we finally found a site in the Scripps Ranch neighborhood of San Diego. We were in good stead, surrounded by a host of local breweries; we were in the sweet spot of the San Diego brewing scene. We were now ready to start building our brewery.

So if we are going to make good beer, capable of standing up to the quality being produced by the premier brewers in San Diego, we had to be able to control a number of process parameters. Brewing good beer means controlling time, temperature and process flow. We also had to be meticulous about a clean environment, incoming water quality, capturing data, monitoring the process and ensuring that we used the highest quality equipment and raw materials. Being a small brewery, we invested in an all electric 3BBL brew house with full PLC control to automate temperature control and resident times. The brew house is made up of a HLT using a herms coil to control mash temperatures, a mash tun and a combination kettle/whirlpool. For fermentation and conditioning we have six 3BBL fermenters and two brites. It’s not high volume, but it’s a start.

Incoming water quality is controlled by a hybrid water softener followed by a reverse osmosis system allowing us to eliminate the chorines and chloramines, and varying the degree of hardness for the various styles of beer we’ll be brewing.

Quality control, testing incoming raw materials, propagating and preparing yeast and testing for bacteria levels required having a lab. So, we built one, a testament to our focus on the science of beer and the quality of beer we want to produce.

We built a tasting room as well. Its small and intimate, but capable of serving up some really tasty beers.

The build out of the cellar, cold room, chiller glycol loop, drains, keg wash station, electrical, plumbing, glass washer, etc, etc, took some time to complete. After 8 months of construction, we were finally able to open to the public.

We’re now off and running! We hope you enjoy our beer. We look forward to meeting all of you at the brewery.

Our Logo

Our logo reflects our Irish heritage and pays homage to our family origins emanating from the counties of Cork and Kerry in Southwest Ireland. The fishing village depicted in our logo is of Dingle, located on Dingle Bay in County Kerry. It is believed, records are sketchy, that our father’s side of the family harkened from the village of Ballyferriter, or thereabouts, which is just up the road from Dingle. Our ancestors were most likely farmers or fishermen, and if you were the youngest son, it’s likely you were a priest. We don’t have any evidence that any of our ancestors were brewers, but I can say all our ancestors were very fond of beer.


Our Task


Our task is to create thoughtful and cleverly constructed artisan craft ales and lagers that stimulate the palette and arouse the senses.

We will respect the traditions of the past but will relentlessly challenge our brewers to pursue forward looking recipes, techniques and processes.

We will use science to control, monitor and make intelligent decisions about our recipes and brewing process. We will pursue innovation and keep our thoughts and processes open to creativity.