My last batch of Bohemian lager had a distinctive metallic aftertaste which I traced back to a stainless steel scrub pad that I had placed at the base of the dip tube on my cornelius keg as a filter. The beer was fine until I racked it into the keg and added the filter... seemed like a good idea at the time. After about a day a very noticeable metallic aftertaste developed. I removed the stainless pad but the taste lingered.
EDTA is commonly used to chelate metallic flavors out of food products which can occur during processing. Specifically, Dow sells a product called Versene (I bought some plain old EDTA off of eBay, about $8 for 1lb). Large scale brewers may also use it as a foam stabilizer. It is added to many different food products as a color and flavor preservative. The Dow literature recommends 30 ppm concentration; it is safe in concentrations much, much higher.
Long story short, I added 500 mg to 19L of beer (about 1/4 teaspoon) and the metallic flavor disappeared instantly. Note: 1 ppm = 1 mg/kg. 19L = approx 19 kg. so 500 mg/19 kg = 26 ppm
Has anyone else tried this technique?
EDTA is commonly used to chelate metallic flavors out of food products which can occur during processing. Specifically, Dow sells a product called Versene (I bought some plain old EDTA off of eBay, about $8 for 1lb). Large scale brewers may also use it as a foam stabilizer. It is added to many different food products as a color and flavor preservative. The Dow literature recommends 30 ppm concentration; it is safe in concentrations much, much higher.
Long story short, I added 500 mg to 19L of beer (about 1/4 teaspoon) and the metallic flavor disappeared instantly. Note: 1 ppm = 1 mg/kg. 19L = approx 19 kg. so 500 mg/19 kg = 26 ppm
Has anyone else tried this technique?