The company, which files its accounts as Heather Ale Limited, took steps to boost production capacity in Alloa and launch Inn Deep, a bar overlooking the River Kelvin in Glasgow, in the year ended April 30.
Turnover increased by 42% to £4.5 million as the brewer's brands, such as Williams Draught, Caesar Augustus and Joker IPA, gained new listings in supermarkets and built sales overseas.
Notable progress was made in Russia which, along with the US, Canada, Sweden and Italy, is a key export market for the firm, while further listings were secured in Sainsbury's. This came after three of its beers came in the top five in a taste contest run by the supermarket in Scotland, the north of England and Northern Ireland.
Williams' turnover for the year included a £300,000 contribution from Inn Deep, though this was not for a full year.
Managing director Scott Williams said the bar had sustained a "significant trading loss" in its first year, making the company's performance less impressive than it had hoped. However, he said the bar would not impinge on the Heather balance sheet going forward because it has since been hived into a separate trading entity, The Inn House Brewery Company.
That company also includes Valhalla's Goat, an off-licence nearby on Great Western Road.
Mr Williams said depreciation charges also deepened at the company after it invested heavily in updating its brewing equipment in Alloa.
That expenditure included a £250,000 investment in a new bottling line, grain silos, eight new fermentation and conditioning tanks and upgrading the brewery's electricity supply. The company is planning further investment this year with the purchase of a small canning line, allowing it improve the packaging service it provides for brewers such as Fyne Ales, Inveralmond Brewery, Isle of Skye Brewery and Traditional Scottish Ales.
Mr Williams, who founded the business with his brother Bruce in 1992, said: "I guess taking over the bar, which in its first trading year made a significant loss, would have made the figures look not quite as good as we hoped they would be. In saying that, it is something that has now been stripped out of it.
"We spent a lot more money on equipment, so depreciation charges went up a lot. There were a few one-off investments as well, which hit the bottom line, but overall, it was pretty good."
Meanwhile, The Vintage Bar in Leith, owned separately by Williams Bros, became one of the first two Scottish outlets to be named in the UK's Top 50 Gastro Pubs. The scheme is run by trade publication The Publican's Morning Advertiser.