Molasses and sour taste

[TNTurkey]

I brewed a seasonal (Christmas) ale last December and was very disappointed in it. It had a distinctly sour taste that I originally attributed to a contamination in my equipment. Never was very happy with that explanation because the beers before and after were really good. I'm also careful about sanitization-not saying it can't happen, but it never has before that I know of.
A friend told me the other day that molasses can impart a sour taste. He said that after all the sugar from the molasses has been metabolized, the remaining flavor gives a sour note.
This is the first time I've brewed with molasses.The recipe is below-it includes blackstrap molasses at about 2.5% of the fermentable sugar.
Any thoughts?
Thanks.

18# Pale Marris Otter
1 # Crystal 80L
.5# Black patent
Horizon hops 60'
Ginger powder .25 tsp.
Cinnamon powder 0.5 tsp
Allspice 1/8 tsp
Nutmeg 1/8 tsp
Wyeast 1028 London ale yeast
Molasses 8 fluid oz.

 

[clone63]

I've brewed with molasses once. It was a little odd, I don't know if sour is the best word for it, but I could definitely see it called that way.. Without tasting I can't say. Definitely in the list of potential culprits. If it fermented fine and didn't sit in primary too long, I would not think contamination. Is the water source one you've always used with good results?

You could ferment like a half-liter of 1.03 molasses water and taste it, see if it hints at what you're tasting..

 

[RPh_Guy]

No, molasses isn't sour, it's metallic. Taste it.

Contamination can happen randomly, even if you didn't do anything wrong.

 

[Silver_Is_Money]

Molasses has a lot of iron in it. Particularly blackstrap. Back in the mid 90's I brewed a Scotch Ale to which I added Molasses. It only became drinkable after about 8 months of aging.

 

[Soulshine2]

I brewed a seasonal (Christmas) ale last December and was very disappointed in it. It had a distinctly sour taste that I originally attributed to a contamination in my equipment. Never was very happy with that explanation because the beers before and after were really good. I'm also careful about sanitization-not saying it can't happen, but it never has before that I know of.
A friend told me the other day that molasses can impart a sour taste. He said that after all the sugar from the molasses has been metabolized, the remaining flavor gives a sour note.
This is the first time I've brewed with molasses.The recipe is below-it includes blackstrap molasses at about 2.5% of the fermentable sugar.
Any thoughts?
Thanks.

18# Pale Marris Otter
1 # Crystal 80L
.5# Black patent
Horizon hops 60'
Ginger powder .25 tsp.
Cinnamon powder 0.5 tsp
Allspice 1/8 tsp
Nutmeg 1/8 tsp
Wyeast 1028 London ale yeast
Molasses 8 fluid oz.

got a pic of that blackstrap molasses label? I'm thinking you maybe used one that wasnt "unsulphured" and maybe that was the source of the off - flavor.