Cool! I'm glad you were able to salvage it!

What is your pot made of? If it's aluminum, the combination of wine and bay leaf probably contributed to the bitter, metallic taste.

Wait! Good news! I kept adding in sugar and rice vinegar in small amounts, and lastly some chicken stock and it worked! Next time I'll start the shells right into liquid, I think. Thanks to all for the kind assistance.

I've made lots of fish and shellfish broths and never had this happen, so you sent me off to my library and the web. There were lots of references to seafood stocks turning bitter but no really good explanations. The closest I come is the thought that gills, eyes, and some other parts of fish and shellfish can be bitter (definitely true!) and that if you simmer them too long, those flavors emerge in your stock.

So my thought is, that if you want a concentrated stock, you should simmer it for a relatively short time, then filter out the pieces, and then simmer it again. It still doesn't explain to me why I've never had the problem. And doesn't help you--one internet source says that adding salt can counter bitterness, but I think you were right to abandon it. Hoping the best for the rest of your meal!

Ohhh sadness. :(

Bummer. I hope your dinner is great and lots of fun.

I may have left the shells cook in the butter a minute or two too long before adding the wine, but no more than that. Still, I think you've hit on the only possible explanation. Thanks, amysarah. No remedies, the metallic bitterness would ruin the rest of an elaborate meal so, no soup for anyone!

I had a similar thing happen a couple of years back, but with a fish stock. I wanted to make a seafood risotto for my husband's birthday like one he'd loved in Venice. I let the stock simmer a long time, figuring it would intensify the flavor, like with a chicken or veal stock. It also turned sort of acrid or bitter. I wound up running out to the local upscale fish market to buy some of their store-made stock - the owner told me the problem was probably that I'd let it simmer too long. Unfortunately, I had no idea then - or now - how to fix it, but that might at least explain it. (Assuming the same is true for stock made from shrimp shells.)

Thank you for your kind replies. Yes, there is tomato paste (used tubed), but the bitterness developed right away with the stock, which was the shells, butter and salt, cognac and white wine... I'll try some sautéed shallots and more of the sugar and rice vinegar, I guess. Here is the recipe, which probably won't format:


Published: February 5, 2010
1 pound medium or large uncooked shrimp, shelled, shells reserved

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6 tablespoons unsalted butter

1 1/2 teaspoons kosher salt, more to taste

2/3 cup dry white wine

2 tablespoons brandy

3 thyme sprigs

1 bay leaf

2 celery ribs, chopped

2 large leeks, white and light green parts only, chopped

2 garlic cloves, chopped

1 fennel bulb, finely chopped, fronds reserved for garnish

1/4 cup long-grain rice

2 tablespoons tomato paste

Pinch cayenne

Freshly squeezed lemon juice to taste.

1. In a large pot over high heat, cook shrimp shells in 1 tablespoon butter and

1/4 teaspoon salt, stirring frequently, until lightly browned in spots, about 3 minutes. Add wine and brandy and boil until most of the liquid is evaporated. Add 6 cups water, thyme and bay leaf and simmer, uncovered, for 15 minutes. Strain shrimp stock into a bowl, pressing on shells before discarding them.

2. In same pot, melt 2 tablespoons butter with 1/4 teaspoon salt. Add shrimp and sauté until they are pink, 2 to 4 minutes depending on size. Using a slotted spoon, transfer shrimp to a bowl.

3. Add remaining 3 tablespoons butter to pot along with celery, leeks, garlic and fennel and sauté until softened, about 5 minutes. Stir in the rice, tomato paste, cayenne and remaining salt and sauté for 2 minutes. Add shrimp stock and simmer, covered, until rice is tender, about 20 minutes.

4. Set aside 4 to 6 nice-looking shrimp and stir remainder into bisque; let cook for 2 minutes. Working carefully and in batches, pour bisque into a blender and process to a smooth purée or pulse to a chunky mixture, as you like. (You may use an immersion blender to purée soup.) Return bisque to pot. Stir in the lemon juice and additional salt to taste. Reheat if necessary before serving. Garnish each bowl with a shrimp and a piece of fennel frond.

Yield: 4 to 6 servings.

I agree with iuzzini, and though I feel like I may be muddying up your recipe --some red pepper flakes or something with heat might work--more as a distractor.

Maybe take a small portion out and add a little bit of cream or half-and-half to it and see if it helps? It'll suck if you have to pitch the soup!

Did it have any tomato paste in it? Occasionally I think canned tomato products can have an off flavor depending on the brand. Have you incorporated sherry/brandy, cream, shallots or onions sauteed in butter? These might work . ..

The stock I made from the reserved shells was bitter from the start, despite the fresh shimp sauteing up wonderfully sweet. So I don't know

What else is in the bisque? What do you think is causing the bitter aftertaste?