Any self respecting beer lover has at least peered through brewpub windows at the stainless hardware in the brewery, where the magic (blood, sweat, and tears) happens. Most of us have set foot in a real brewery to dream about what goes on inside those shiny vessels. Some of us even cowboy or cowgirl up and wrangle various strains of saccharomyces cerivisiae or pastorianus at home to make our own signature brews. Regardless of location, sophistication, and capacity the basics of brewing science remain a common thread linking the beginning extract homebrewer to the grizzled shift brewing veteran. Specific combinations of temperature, time, and pH have been the unchanging keys to unlocking those precious malted barley starches, native enzymes, and sugar molecules. Until now.
Scientists found that boiling the wort wasn’t necessary
Before continuing, I’m going to assume you are familiar with a few brewing basics as we employ them today: Crushing malt into grist, soaking grist in hot water of particular temperature and pH ranges, and separating the sugary wort from spent grains before boiling and adding hops. All of this is done to prepare a healthy and robust environment for brewing yeast to make delicious alcohol, carbon dioxide, and the flavors and aromas we find pleasing.
A team of Italian scientists has recently shaken up our commonly accepted brewing temperatures, time commitments, and energy requirements. Utilizing their methods, the time and temperatures necessary to produce fermentable wort were reduced while increasing the amount of sugar extracted from grist. They discovered boiling the wort wasn’t necessary with their method, and maximum hop acid utilization happened in less time than with a traditional boil.
Here’s how they did it: Hydrodynamic cavitation. Or simply put, tiny imploding bubbles. Cavitation of liquid occurs in a blender, for example, or when liquid is forced through a nozzle at relatively high pressure. Tiny bubbles of gas are forced out of solution then rapidly implode, obliterating (or at least weakening) whatever is near them. So, at high speed your blender’s blades aren’t making that margarita or pesto…it’s the destructive force of hydrodynamic cavitation at work. In this case the scientists didn’t use a blender in the brewery, but they circulated whole malted barley and water at high speed and pressure through a nozzle. The cavitation forces pulverized the malt, increasing the amount of available starches in the mash. This method also lowered the temperature threshold required for mash enzymes to function by about 45F; lower temperature equals less energy used.
Following the mash step, as with traditional brewing, spent grains were removed from the wort. The wort was again circulated through a nozzle and pelletized hops were added. Typically wort must be boiling to extract and transform hop acids to the bitter compounds we enjoy. But hydrodynamic cavitation allowed this process to occur at about 1.5 times traditional efficiency, and at about 173F (well under boiling temperature). Again, less heating energy is required with this new method.
If you’re a brewing geek, this is all very exciting. The scientists have effectively removed the time, energy, and equipment cost required to mill malted grain. They’ve reduced heating energy costs and time required to extract sugars and hop acids. A single vessel, pump, heat exchanger, and nozzle were used for the mash and “boil” steps. Of course any amazing new development should leave us with questions, and likely needs refinement. What about malt husk tannin extraction? Will this method work with whole hops? Is the wort properly sterilized, and does “hot break” occur at this lower working temperature? To what extent does wort caramelization occur? Regardless of these and more questions, I am thrilled to see a potential new brewing method emerge with readily available equipment, lower equipment and energy costs, with less space requirement. Brewing and science. They were made for each other!