What could make muffins taste 'Fishy'?

[Carlovski]

My housemate made a batch of Blueberry Muffins at the weekend, she is quite a keen baker and normally everything comes out pretty good.

I had one with my morning cup of tea - first to try one, and it was a bit odd, for some reason it tasted a bit fishy (Also was a bit lacking in sugar, but that's a minor point). She asked me what I thought, and I was a bit reluctant to mention it, I wondered if it might just be me, but when she had one she almost spat it out.

I am sure I have noticed this before, but with commercial products and put it down to using cheap fats/eggs, but all the ingredients appeared to be fine.

Anyone come across this phenomenon before?

She also baked another cake, same oven, similar ingredients (Although a chocolate one which may have masked anything funky), and that was fine.

[JeanneCake]

one thing that comes to mind is old clarified butter or old oil can have that effect; or perhaps the wrong leavening (baking soda instead of powder, but generally this makes for a metallic taste rather than a fishy one....)

[jmolinari]

Canola oil when heated can give off fishy aromas...but i wouldn't thikn that muffins would get hot enough for that.

[ChrisTaylor]

Heh ... sounds odd, but this one time I bought raspberries from the supermarket and they tasted kind of fishy. Suspect the berries. Always.

[MelissaH]

My first thought was canola oil. I've had bottles of canola oil that start to smell fishy after relatively short periods of storage in a dark and cool cabinet. It didn't need to be heated to get that fishy smell. I won't buy canola oil anymore.

MelissaH

[Carlovski]

Don't think there was any canola oil involved.

The Berries I guess would be the prime suspect, but I'm almost certain a few went in the cook while she was cooking and she didn't say anything! I suppose a few rogue ones could have caused it.

[David A. Goldfarb]

If there was no canola oil, I'd suspect the eggs. Fish meal is sometimes used in chicken feed.

[Blether]

Was there wholewheat flour in the muffins ? The oils in it will go rancid if it's kept too long, and that produces off flavours.

[Carlovski]

I'll double check, but I think it was white flour, and from a freshly opened pack.

[HungryC]

Canola oil was my immediate first guess, too: but I'd also suspect the butter. It can definitely absorb flavors while in the fridge or freezer, and it can certainly go "off".

[highchef]

First thoughts..

Were the berries frozen? They aren't packaged in a vacume, because they are flash frozen to keep them separated from each other and not be a glob. If stored next to seafood, they will pick up on that.

I keep flour, in it's bag in a heavy duty zip loc on separate shelves in the freezer. I also put all seafood in the bottom basket just in case it accidentally thaws. Since it's packed in water it just drips to the bottom of the freezer and not onto anything else. Butter stays in freezer in zip loc as well, right next to flour.

You can rule out the canola in a heartbeat...just smell what's left in the bottle. It will be easy to tell if it's rancid when your nose is right there at the opening.

[Tri2Cook]

If there was no canola oil, I'd suspect the eggs. Fish meal is sometimes used in chicken feed.

Flax seed is also sometimes used in chicken feed in an effort to boost omega 3 in eggs. Anyone who's spent much time with flax oil capsules can probably attest that those can sometimes lean heavily to the fishy side.

[Sebastian]

The oil(s) used oxidized. Lipids that are soft (butter) or fluid (oils) at room temperature are highly unsaturated, meaning they are very susceptible to oxidation degradation. one of the tell tale signs of oxidized oils is off flavor - from cardboard to fish. By the time you get to fish, your oils have been heavily oxidized. If there's any question at all, simply take a spoon of the oil used to make them and taste it. if that's the source, you'll know immediately.