Why blackberries taste bitter & sour (and how to fix it)

You may have noticed that some blackberries taste bitter or way too sour, while other summer berries like raspberries or blueberries don't. This is mainly a problem in underripe blackberries that are picked early for distribution to grocery stores.

Adding sugar or fat (like heavy cream / whipped cream) balances out the bitter and sour flavors, and salt reduces our ability to taste it. The bitter compounds and acidity also break down with heat, so a pork tenderloin simmered with blackberries will taste less bitter or sour, as will a blackberry pie.

Jump to:

• What do blackberries taste like?
• Underripe blackberries
• Why are blackberries bitter?
• How to sweeten blackberries
• Super-tasters & bitter receptors
• Buy boysenberries or another fruit
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What do blackberries taste like?

Ripe blackberries are sweet, pleasantly tart with notes of plum, cherry, and rose. They're also described as having a wine-like flavor, both for the fruity flavors as well as the tannic finish.

Most berries have a bright tart flavor because they are high in citric acid (think lemons). But blackberries' acidity is mostly from malic acid (think apples) which gives them a sour-apple tartness.

A lot of blackberries we buy at supermarkets are underripe, which dramatically affects their flavor. Underripe blackberries are extremely high in malic acid, giving them a very sour flavor.

Underripe blackberries

Blackberries that are picked too early can taste pretty bad, if I'm being honest.

• Very bitter
• Sour
• Too tannic
• Metallic or chemical flavors
• Almost no aroma

Underripe blackberries are very high in acid and low in sugar. This combination tastes sour because the sugar levels are so low, the acid is front and center.

Instead of dark fruit flavors, you get green apple from very high malic acid levels alongside grassy flavors from the aldehydes. Those green grassy flavors fade as the fruit ripens.

Underripe blackberries are also very bitter and tannic, almost tasting metallic or like chemicals. Those tannic compounds are softened as the fruit ripens. As it ripens, the dark fruity flavors develop along with the floral aromas, which are almost completely absent when unripe.

Why are blackberries bitter?

The amount of time the blackberry was allowed to ripen affects how bitter or sweet it will taste. Unripe berries start out bitter and that lessens as they ripen on the vine. When picked fully ripe, blackberries taste very sweet with no trace of bitterness.

Unripe blackberries often make their way into grocery stores because they ship better and store longer (two things grocery stores prioritize). Once the berries are picked, they no longer get sweeter (or less bitter). However, they'll still have their characteristic dark color, making it nearly impossible to tell how they'll taste just by looking at them.

Farmers markets usually have better quality than the grocery store (as they don't need to be picked unripe to endure shipping). Most sellers at farmers markets also let you sample the fruit, so you know exactly how sweet they will be before buying.

Lastly, weather and growing conditions can affect bitterness. Most experts agree under-watering or below-average rainfall results in higher levels of bitter compounds in blackberries. But on the flip side, heavy rainfalls shortly before harvest can dilute their flavor, making them taste bland.

How to reduce bitterness

You did your best to find ripe, sweet blackberries and now you're stuck with a bitter disappointment. When eating fresh out of hand, there isn't anything you can really do to save them. But on the up side, there's a lot you can do make them taste great for anything else.

Remove seeds

Bitterness is concentrated in the white core and seeds. While you can't really 'core' a blackberry, you can at least remove seeds in certain cases. For example, if you're making a sauce, jam, ice cream, or smoothie, you can easily strain out the seeds.

You can also try using up a bitter bunch in a blackberry vinaigrette where the seeds are strained out and then it's sweetened with honey.

Balance bitter with fat

Rich food often benefits from a little added bitterness, and the other way around. In the case of blackberries, adding them to ice cream creates a balanced sweet-fat-bitter combination that can actually end up more interesting. You can also try eating fresh berries with whipped cream.

Blackberries and cheese pair well together too, making them a nice addition to a charcuterie board.

Adding to salads can work if done right. Use mild greens (avoid bitter ones like endive), then add blackberries, a fatty meat like prosciutto, cheese, and a good olive oil dressing (more fat).

Blackberry recipe collection.

Add sugar & salt

Sugar will mask some bitterness, making jams, syrups, sauces, ice creams, and pies a good option. They also work well when paired with other, sweeter fruit like peaches.

Look at grapefruit for example, less bitter grapefruit taste sweeter and adding sugar to a bitter grapefruit reduces bitterness.

Salt reduces our ability to taste bitterness, so using blackberries in savory food works out really well and often adds extra complexity to the dish. Pork, steak, duck, and venison all pair well with a blackberry sauce or reduction.

Use heat

The bitter compounds break down with heat, so you can turn to baking or stove-top cooking to fix your blackberries. This is one of the best options, in my opinion, because it allows you to use several methods at the same time.

For example, blackberry pie uses sugar, a tiny amount of salt (that may or may not be enough to reduce bitterness), and heat. Pairing meat with a blackberry reduction uses heat, salt, and often sugar.

You can also get creative and cook blackberries down into a sauce before adding to a smoothie, ice cream, or even a salad dressing.

How to sweeten blackberries

Sugar is the best way to make sour blackberries taste better. Sweeten blackberries by adding 1-2 tablespoons of granulated sugar per cup of blackberries. That might seem like a lot, but it is necessary for underripe blackberries.

If you want to use honey or maple syrup, reduce the amount by about 30%, so use 2 to 4 heaping teaspoons to start, increasing as needed.

If the bitter or tannic flavors still linger after sweetening the blackberries, try adding a pinch of salt or fat (like mixing them with yogurt or ice cream).

If you are willing to cook them down, their sugars will concentrate, making them sweeter as well. You can also add sugar and let it sit, essentially macerating the berries.

Many blackberry recipes also counter the sour, bitter, and tannic flavors. Both blackberry jam and syrup use so much sugar that it should be nice and sweet without tasting sour at all.

They also taste better when baked into a blackberry cobbler, pie, or even muffins. Think of cranberries and how tart and bitter they can be when raw, but delicious when added to muffins. The idea is the same for blackberries.

Super-tasters & bitter receptors

If you've tried to reduce bitterness and it still doesn't seem like enough, perhaps you are a super taster. About 25% of people are super tasters, which means they have twice as many taste buds (or even more) than the average person. This means flavors are more intense, from bitterness to the heat from a hot sauce.

Some people are also able to detect certain bitter compounds, while others cannot. I attended a food conference where we used test strips (like these) to determine who could sense bitterness. I was able to detect the bitter compound being tested and I also was identified as a super taster.

That test strip tasted so extremely bitter to me that I couldn't get the taste out of my mouth for an hour. Meanwhile other people shrugged it off, claiming it just tasted like paper.

Buy boysenberries or another fruit

Boysenberries look like a red-purple version of blackberry rather than the blue-black color of blackberries. Boysenberries are actually a cross between a raspberry and blackberry, making them naturally taste sweeter and usually less bitter than blackberries.

Most any recipe will work when substituting boysenberries, from pies to reductions for meat. Raspberries can also work but they don't add as much complexity to meat dishes. They also tend to add sweet on top of more sweet for desserts that call for blackberries (which are relying on some of the bitterness for balance).

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