I've been trying to figure this one out today...here goes. My brother is telling me that his portion of an IPA batch (that I was so generous to give him as payment for help with brewing and bottling) seems to have some metallic off flavors from what he says.
Looked up what Palmer has to say:
"Metallic flavors are usually caused by unprotected metals dissolving into the wort but can also be caused by the hydrolysis of lipids in poorly stored malts. Iron and aluminum can cause metallic flavors leaching into the wort during the boil. The small amount could be considered to be nutritional if it weren't for the bad taste. Nicks and cracks ceramic coated steel pots are a common cause as are high iron levels in well water. Stainless steel pots will not contribute any metallic flavors. Aluminum pots usually won't cause metallic flavors unless the brewing water is alkaline with a pH level greater than 9. Shiny new aluminum pots will sometimes turn black when boiling water due to chlorine and carbonates in the water.
The protective (grayish) oxides of aluminum can be enhanced by heating the clean pot in a dry oven at 250°F for about 6 hours"
- Don't use a ceramic coated steel pot
- Used spring water from the store (same brand as always...had good results)
- Use a stainless kettle that is really new
The one thing that stuck out:
"...also be caused by the hydrolysis of lipids in poorly stored malts"
Grains steeped:
1 # Victory
1 # Carapils
1 # Caramel 60
The Caramel 60 was pre-milled and stored in a foodsaver vacuum sealed bag in the freezer for about a month. Could this be the culprit?
Strange thing...I've yet to encounter a bottle with this off taste. What gives? Should I not store grains that have been milled?
Looked up what Palmer has to say:
"Metallic flavors are usually caused by unprotected metals dissolving into the wort but can also be caused by the hydrolysis of lipids in poorly stored malts. Iron and aluminum can cause metallic flavors leaching into the wort during the boil. The small amount could be considered to be nutritional if it weren't for the bad taste. Nicks and cracks ceramic coated steel pots are a common cause as are high iron levels in well water. Stainless steel pots will not contribute any metallic flavors. Aluminum pots usually won't cause metallic flavors unless the brewing water is alkaline with a pH level greater than 9. Shiny new aluminum pots will sometimes turn black when boiling water due to chlorine and carbonates in the water.
The protective (grayish) oxides of aluminum can be enhanced by heating the clean pot in a dry oven at 250°F for about 6 hours"
- Don't use a ceramic coated steel pot
- Used spring water from the store (same brand as always...had good results)
- Use a stainless kettle that is really new
The one thing that stuck out:
"...also be caused by the hydrolysis of lipids in poorly stored malts"
Grains steeped:
1 # Victory
1 # Carapils
1 # Caramel 60
The Caramel 60 was pre-milled and stored in a foodsaver vacuum sealed bag in the freezer for about a month. Could this be the culprit?
Strange thing...I've yet to encounter a bottle with this off taste. What gives? Should I not store grains that have been milled?
