hop culture
Hops in Sours An overview of Bretts, sours and East Coast Yeast. By Joe Bair
The bittering use of hops in sours is negligible. They are only used for the preservative and clarifying properties. Although the tongue tastes bitter alpha acids of hops and lactic acid sours differently, it is still difficult to differentiate both when they are competing together. The pH scale is 1-14, less than 7 is acidic; and greater than 7 is base or alkaline. This scale was introduced at the Carlsberg Laboratory (part of Carlsberg Brewery) in 1909. Most sours are a function of time which allows the different species of bacteria to lower pH. The pH is lowered by acid producing bacteria whose living conditions on the pH range are sensitive. They multiply in the right pH range as their empires rise. They then fall when they cannot live in their lower pH they created. This happens over time to lower the pH to around 3 pH in the sour, 4 pH is normal for beer. Sometimes lambic producers add fruit, which has more acids from the skins of the fruit. You can see why they call it sours. Lactic Acid bacteria do not get along with hops when the IBUs are above 10. Tomme Arthur of Port/Lost Abbey Brewing said he does not use the traditional aged/cheesy hops whose alpha’s decline with time, he just adds a very small amount of fresh noble or aroma hops and keeps the IBUs under 3.
What are Bretts and Sours? “What’s new?” Is what I hear, especially when it comes to beer; this new could be hops, yeasts, ingredients, methods, packaging, place of origin, whatever. It is up to the brewer to answer this question, and create something experimental or “new” to be liked. The latest “new,” is actually old, Brettanomyces (Bretts, wild brews) and acid producing bacteria (lambics, sours) or both together. Bretts have many strains including lambicus, bruxellensis, anomalous, claussenii, custersianus, nanus, naardenensis. Wild yeast (5-10 microns) can supplement or replace normal beer brewing yeast Saccharomyces Cerevisiae.
32
phillybeerscene.com
There are also other Saccharomyces yeast strains, such as the sherry wine yeast Saccharomyces fermentati used in sours. Lactic acid bacteria are a small (1-2 microns) species, they are widely used in foods you eat every day and are possibly part of your probiotic diet (i.e. Lactobacillus, Pediococcus), and other strains have symbiotic relationships with these wild yeasts that together make lambics or sours. These ubiquitous airborne species provide the process for which alcoholic drinks were discovered and the reason you close fermentation vats–to avoid spoilage by these organisms. If you are open fermenting, you can capture, grow, store and reuse these “bugs” from the unfiltered dregs on the bottom of the bottle (or fermenting vat). Also, you can source or isolate specific strains to blend these onecelled beings and pass it on to brewers. This is the story of the Buck’s, our local yeast wranglers - and founders of East Coast Yeast.
october/november2012
Technology and the Evolution of Liquid Yeast In the ‘80s-‘90s, unrefrigerated white packs labeled “brewing yeast 5 grams” were used despite being highly contaminated with bacteria. This dry generic brewing yeast evolved to better meet homebrewer’s demands. Pioneer liquid yeast manufacturers namely, BrewTec, Yeast Culture Kit and Yeast Lab tried, but the fermenter had taken the time to grow the yeast to have an acceptable cell count for pitching into 5 gallons of wort. In 1985, the team of Dave Logsdon and Jeannette KreftLogsdon introduced the Wyeast “smack pack,” which was packaged in a plastic metallic gusset hermetically sealed bag with barely enough (25B cells) to pitch a low gravity 5 gallon batch without a starter. The gusset bag design provided room for the CO2 to proof that the cells were active before pitching. Research found that higher pitch rates were needed and when Chris White and Lisa White started