Brewing in Copper: The Good, the Bad, and the Polishing The Effects of Metal Ions in Wort and Beer

The Good Copper’s effect on sulfur Copper acts to reduce concentrations of hydrogen sulfide Much information in wine industry Copper as a micronutrient for yeast Needed for yeast in trace amounts It’s really, really pretty

Ion Paper “The Influence of Heavy Metal Ions on Beer Flavour Stability” Three ions were studied for their effects on beer flavor stability Cu, Fe, Mn Procedure Exogenous heavy metal ions were added at various concentrations at two points in the process Kettle full wort pre-boil Post-fermentation How they determined effect Chemiluminescence

Ion Paper “The Influence of Heavy Metal Ions on Beer Flavour Stability” Conclusions Kettle full wort pre-boil Cu and Fe – “No negative influences due to higher concentrations up to three fold of normal concentrations” Testers noted large reductions in Cu and Fe during fermentation Post-fermentation Most damaging Cu > Fe > Mn Mn was determined to damage flavor stability regardless of where in the process it was added

Prost Brewhouse Materials Solid copper brewhouse Curved bottom with 3,000,000 BTU “Dragon” Bronze false bottom Zinc and Copper Iron beam with stainless steel rakes Copper process pipes

Lab results for Prost Water, Wort, and Beer SAMPLE FeCu WATER13 ppm6 ppm WORT109 ppm96 ppm BEER66 ppm45 ppm *Coors targets 60ppm> because of added iron from the Enzinger filter

The Bad Copper is mutagenic, accumulates in cells Yeast weakness Iron in concentration of 1mg/l can give rise to darker colors due to the interaction of Fe and the phenolic substances from malt and hops Fe can give rise to astringent flavors, haze and flavor stability problems. >.1mg/l is the target for brewing liquor Enzinger filter Evolution of haze Pro-oxidant effects

Anecdotal Switching from Copper to Stainless THE FOG….. Switching from Stainless to Copper Noticed a reduction in sulfur in lager beers especially – able to “cap” beers sooner than previously experienced Yeast weakness at other breweries? CIP greatly reduced Ashleigh thought it would take the same amount of time to polish as the brewhouse at Dry Dock……It doesn’t

The Polishing

Thanks and Acknowledegements Troy Casey Jeff Nickel Ashleigh Carter Coors QC Lab ‘The Influence of Heavy Metal Ions on Beer Flavour Stability’ C. Zufall and Th. Tyrell

“Ein Prosit” Ein Prosit, Ein Prosit, der Gemütlichkeit Eins, zwei, drei, d’suffa Zicke, zacke, zicke, zacke, hoi, hoi, hoi PROST!