About one and a half years ago, I brewed a golden sour with a mix of microbes. These microbes included WLP665, WLP672, and dregs from Russian River Consecration, Firestone Walker Feral One, Prairie Gold, Oud Beersel Geuze, and Jolly Pumpkin Oro de Calabaza. The original golden sour was transferred on top of about 5 lbs of pureed apricots and the mixed culture lived on in the one or two gallons of beer that remained. It has since fermented a barrel aged dark sour, a cherry golden sour, a golden sour with Muscat and Cabernet Sauvignon grapes, and another apricot golden sour.
The culture is currently fermenting another golden sour which I am considering dry hopping depending on how the flavors develop. My typical golden sour recipe consists of:
65% Pilsner Malt
25% Wheat Malt
5% Vienna Malt
5% Flaked Wheat
But I do not think the base malt and wheat percentages will make or break the final product. This is a beer that is dominated by the yeast and bacteria.
I typically mash at 154°F or above, aim for an OG between 1.040 and 1.050 and use little to no hops. If I use hops, the IBUs are under 10. The hops can be a good way to adjust the balance of yeast and bacteria activity. Most Lactobacillus strains are not very hop tolerant. So if you find that your beer is souring too quickly, increasing the IBUs can potentially slow down the bacteria. Every two or three batches, I have also added a fresh pitch of Saccharomyces as the Brettanomyces and bacteria will slowly take over the culture over time.
Overall, I have found this method very effective in developing a unique and strong mixed culture of yeast and bacteria that has produced some tasty sour beers. The use of commercial strains along with bottle dregs will provide a varied blend that will give a house character and signature especially after a few generations of fermentation.