How to Make Sour Cream at Home: Traditional Cultured Sour Cream

NPSelection
Sep 22, 2023
12 min read

How to Differentiate Sour Cream and Crème Fraîche

How to make traditional Sour cream and Easy sour cream

Sour cream is one of those foods that seems very simple until you try to make it yourself. At first glance, it is just thick, slightly tangy cream. In reality, traditional sour cream is a fermented food, created when lactic acid bacteria gradually transform fresh cream.

As the cream ferments, it becomes thicker, develops a fresh acidic taste and takes on the familiar texture we associate with sour cream. The process is similar to making yogurt, although cream is used instead of milk. The final result depends on several things, including the type of cream, the starter culture, the fermentation temperature and how long the cream is allowed to ferment.

Making sour cream at home gives you much more control over the result. You can make it mild and rich, more like crème fraîche, or leave it longer for a sharper and more traditional sour cream flavour.

What Is Sour Cream?

Traditional sour cream is cream that has been fermented with lactic acid bacteria.

In the past, cream was not always separated from milk using modern machinery. Fresh milk was left to stand, allowing the cream to rise naturally to the surface. This layer was then collected and allowed to sour through natural fermentation.

Today, the process can be made much more predictable by adding a selected starter culture to fresh cream. The bacteria consume some of the natural milk sugar and produce lactic acid. This acidity changes both the taste and the structure of the cream, helping it become thicker and pleasantly sour.

Traditional cultured cream appears in many cuisines. In Central and Eastern Europe, similar products may be known as smetana or tejföl. They are used in soups, sauces, baked dishes, potatoes, dumplings, desserts and many everyday meals.

Although commercial sour cream is widely available, homemade sour cream often has a fresher and more complex flavour. It can also be adjusted to suit your own preference.

Sour Cream Versus Crème Fraîche

Sour cream and crème fraîche are very closely related. In fact, when making them at home, the difference can sometimes be more about the fermentation time than the starter itself.

Crème fraîche is generally richer, milder and less acidic. It is usually made with cream that has a high fat content and is fermented only until it develops a gentle cultured taste. Its texture is smooth and luxurious, while its flavour remains fairly delicate.

Sour cream is usually sharper and more noticeably acidic. It may be made from slightly lower-fat cream, although double cream or heavy cream can also be used. The main difference is that sour cream is normally fermented for longer, allowing more acidity to develop.

This means that one batch can sometimes move from crème fraîche to sour cream simply by being left to ferment for a little longer. If you prefer a mild and creamy result, stop the fermentation earlier. If you want a stronger sour flavour, allow more time.

There is no exact moment when crème fraîche suddenly becomes sour cream. The change is gradual, and personal taste plays an important role.

Traditional Cultured Sour Cream Versus Cream Thickened with Lemon Juice

Many quick recipes describe a mixture of cream and lemon juice or vinegar as homemade sour cream. This can be useful in an emergency, but it is not the same as traditionally cultured sour cream.

When lemon juice or vinegar is added to cream, the acid immediately changes the flavour and can also make the cream slightly thicker. The result may work well in a dip, sauce or cake recipe, especially when sour cream is needed quickly.

However, no real fermentation takes place. The cream is simply being acidified.

Cultured sour cream develops slowly through the activity of living bacteria. During this process, the cream changes in a more complex way. The flavour becomes rounded and fresh rather than simply acidic, and the texture develops naturally over time.

Another important difference is that traditionally cultured sour cream can often be used to start another batch. Cream thickened with lemon juice cannot be recultured because it does not contain an active starter culture.

The quick lemon juice method has its place, but it is better described as a sour cream substitute rather than true cultured sour cream.

Choosing the Right Cream

The type of cream you use has a strong influence on the finished texture.

Double cream is an excellent choice if you want a very thick and rich sour cream. Its high fat content gives the finished product a smooth, dense and spoonable consistency.

Heavy cream or heavy whipping cream also works very well. It normally creates a creamy and satisfying result, although it may be slightly softer than sour cream made from UK double cream.

Whipping cream can also be used, provided it has enough fat and does not contain ingredients that interfere with fermentation.

Single cream and other lower-fat creams may still ferment, but the result is usually thinner. Fermentation can increase acidity and change the structure, but it cannot replace the richness created by fat. If the cream contains more water, the final sour cream will naturally be softer.

For the best result, choose fresh pasteurised cream with a simple ingredient list. Cream containing large amounts of stabilisers, preservatives, sugar or flavourings may behave less predictably.

Ultra-heat-treated cream can also work, although some brands ferment better than others. The important thing is to start with fresh cream that smells and tastes normal.

Never use cream that is close to spoiling. Fermentation does not make old or unsafe cream suitable to eat.

Choosing a Starter Culture

Several cultures can be used to make sour cream at home.

A Nordic-style starter is particularly suitable because these cultures are traditionally used for fermented dairy products such as cultured buttermilk, filmjölk, crème fraîche and sour cream.

A mild kefir starter can also be used. This may create a slightly more complex flavour because kefir cultures can contain both bacteria and yeast. The result may be mildly tangy and sometimes more aromatic than sour cream made with a yogurt culture.

A Bulgarian yogurt starter is another possibility. It can produce a stronger yogurt-like acidity, particularly when fermented at a warmer temperature.

You can also use plain homemade yogurt, milk kefir or sour cream from a previous successful batch. These are already active, so they may begin fermenting the cream more quickly than a freeze-dried starter.

Whatever starter you choose, it should be fresh, plain and free from sweeteners or flavourings. A starter taken from a weak, old or questionable batch should not be used.

Different cultures behave differently, so it is always sensible to follow the instructions supplied with the starter. The same starters can also be used to prepare a variety of homemade cultured dairy products, including cultured butter, buttermilk, crème fraîche, mascarpone and soft cheese.

Preparation Temperature

The correct fermentation temperature depends on the microorganisms in the starter.

Some cultures prefer warmer conditions, while others are designed to work at lower temperatures. For this reason, the instructions for the selected starter should always take priority.

For many yogurt and kefir starters used to ferment cream, a temperature somewhere between 30°C and 40°C may be suitable. The cream should feel warm, but it must not be hot.

If the cream is too hot when the starter is added, the microorganisms may be damaged. If the temperature is too low, fermentation may be very slow or may not begin properly.

A yogurt maker is useful because it maintains a stable temperature. A multicooker, insulated container or another suitable appliance can also be used, but the true temperature should be checked.

Some machines become warmer than the temperature shown on the display. A basic kitchen thermometer can prevent many failed batches.

Fermentation Time

Fermentation time is never completely fixed.

The same recipe may take a different amount of time depending on the cream, the starter, the room temperature and the strength of the previous batch.

When using already active yogurt, kefir or cultured sour cream, the cream may begin to thicken within a few hours. It is sensible to start checking after about three hours. In some cases, the sour cream may be ready after three to six hours.

When using a freeze-dried starter, the first batch usually takes longer. Begin checking after approximately twelve hours. Depending on the starter and temperature, it may need around twelve to eighteen hours, and occasionally longer.

When no temperature-controlled appliance is used, fermentation can take twenty-four to forty-eight hours. Room temperature changes can make this method less predictable.

The most useful guide is not the clock but the cream itself.

It should smell fresh and cultured, taste pleasantly acidic and show some thickening. A shorter fermentation will give a mild crème fraîche-style result. A longer fermentation will create a sharper sour cream.

The jars should remain still during fermentation. Repeated stirring, shaking or moving can disturb the forming structure and lead to a thinner or separated result.

What the Finished Sour Cream Should Be Like

Homemade sour cream should have a clean, fresh and slightly tangy smell. The flavour can range from mild to distinctly sour, depending on how long it was fermented.

The texture should be creamy and generally thick enough to hold on a spoon, although this depends heavily on the fat content of the cream.

Do not judge the final thickness while the sour cream is still warm. It will usually become firmer after several hours in the refrigerator, as the fat cools and the fermented structure settles.

A small amount of liquid on the surface is not always a sign of failure. This may simply be whey separating from the cream, particularly if it has fermented for a long time or has been moved before setting.

If the smell and appearance are normal, this liquid can usually be gently stirred back in after the sour cream has cooled.

The finished product should never smell rotten, bitter or strongly unpleasant. It should not show mould, strange colours or unexpected heavy bubbling.

How to Make Sour Cream at Home Step by Step

Begin by cleaning everything that will touch the cream. Wash your hands and thoroughly clean the jars, spoons, whisk and work surface. Rinse the equipment with very hot water and allow it to drain.
Good hygiene is especially important because sour cream is fermented for several hours at a warm temperature.

Pour one litre of fresh double cream, heavy cream or whipping cream into a clean saucepan or bowl.
Warm it gently until it is lukewarm. Do not overheat it. Unless your particular starter instructions say otherwise, there is no need to boil the cream.

Once the cream has reached the correct temperature, add the starter.
When using a freeze-dried culture, use the quantity stated in the product instructions. When using fresh yogurt, kefir or sour cream from a previous batch, add a small amount and mix it thoroughly through the cream.

Stir for several minutes so the starter is evenly distributed.
If using a dried starter, allow the mixture to stand for around ten to fifteen minutes. This gives the culture time to absorb moisture and adapt to the cream.

Pour the mixture into clean jars and close or cover them according to the instructions for your fermentation device.

Place the jars in the yogurt maker, multicooker or another warm environment. Maintain the recommended temperature and leave the jars undisturbed.

Begin checking the cream at the appropriate time. With an active starter, this may be after three hours. With a freeze-dried starter, checking after twelve hours is more realistic.

When the sour cream has developed the taste and consistency you prefer, move it immediately to the refrigerator.

Allow it to chill for several hours before stirring or serving. The flavour will become more balanced, and the texture will normally become thicker.

How to Reculture Sour Cream

A successful batch of homemade sour cream can often be used to start the next one.

Before serving the sour cream, place a small amount into a separate clean container. This reduces the chance of contaminating the portion you plan to use as a starter.

To make another batch, warm fresh cream until it is lukewarm. Add one or two tablespoons of the previous sour cream for each litre of cream and mix thoroughly.

Incubate it under the same conditions as before.

Because the culture is already active, the new batch may ferment more quickly. Begin checking it after a few hours.

Reculturing is convenient, but it should not continue indefinitely. Every time a batch is handled, there is a possibility of introducing unwanted microorganisms. The balance of the starter may also change gradually over repeated batches. A Nordic-style starter can be used for the first batch, after which a spoonful of a successful batch may be saved to reculture the next preparation.

It is best to begin again with a fresh freeze-dried culture when the sour cream becomes slower to ferment, develops an unusual taste, becomes consistently weak or begins to smell excessively yeasty.

Never use a batch with mould, discolouration or an unpleasant smell to make another one.

Common Problems

For additional help with temperatures, incubation and failed batches, use our Yogurt and Kefir Fermentation Coach.

One of the most common problems is sour cream that does not thicken.

This may happen because the cream contains too little fat, the starter was weak, the temperature was too low, or the cream was too hot when the starter was added. The fermentation time may also have been too short.

If the cream still smells clean and normal, it can be left for a little longer. However, an unsuccessful batch should not be kept warm indefinitely.

Thin sour cream may become noticeably thicker after refrigeration. Always chill it properly before deciding that it has failed.

When a thicker texture is important, use double cream or high-fat heavy cream in the next batch.

Another common problem is excessive acidity. This usually means the cream fermented for too long or at too high a temperature.

Very sour cream can still be useful in cooking, baking, sauces and dips, provided it smells and tastes clean. In the next batch, reduce the fermentation time.

Separation may also occur. This can happen when the batch is over-fermented, overheated, or repeatedly moved while setting.

Refrigerate it before stirring. If the aroma is normal, the separated liquid can often be mixed back in.

A grainy texture is also commonly linked with excessive heat or overly long fermentation.

A mild yeasty aroma can appear when kefir is used as the starter. However, a strong alcoholic or unpleasant yeast smell may indicate that the culture has become unbalanced. Such a batch should not be used for reculturing.

Visible mould means the entire batch must be discarded. Removing only the mouldy area is not sufficient because contamination may extend below the surface.

Storage Guidance

Homemade sour cream should be stored in the refrigerator in a clean container with a secure lid.

Always use a clean spoon when removing some. Eating directly from the storage jar or using a spoon that has already touched other food can introduce unwanted microorganisms.

Because homemade sour cream has not undergone commercial shelf-life testing, it is best to make manageable quantities and use them promptly.

As a cautious guide, aim to consume it within about five to seven days. It should remain refrigerated throughout this time.

Discard it sooner if it develops mould, unusual colours, a rotten smell, heavy bubbling or a bitter and unpleasant taste.

Do not taste a product that already appears spoiled.

Frequently Asked Questions

Can sour cream be made without a yogurt maker?

Yes. The jars can be placed in a warm, draft-free location or inside an insulated container.

Without stable temperature control, fermentation may take twenty-four to forty-eight hours or more. The result may vary depending on the temperature of the room.

Can ordinary yogurt be used as a starter?

Plain yogurt containing live cultures can be used.

Avoid sweetened, flavoured or heat-treated yogurt. The finished cream may have a more yogurt-like taste, depending on the microorganisms present.

Can milk kefir be used?

Yes. Fresh milk kefir or a kefir starter can ferment cream.

The flavour may be slightly different because kefir can contain a wider variety of bacteria and yeast.

Which starter culture is best?

A Nordic-style culture is a particularly good choice for traditional cultured cream.

Mild kefir and Bulgarian yogurt starters may also work, depending on the taste you prefer.

Can single cream be used?

Single cream can ferment, but the result is normally thinner.

Double cream or heavy whipping cream is better when a thick and rich consistency is desired.

Can plant-based cream be fermented?

Some plant-based creams can be fermented, but they do not behave in the same way as dairy cream.

Their fat, sugar and protein contents are different, and many contain stabilisers. They may require a specially adapted method and suitable plant-based starter.

The result is better described as a sour cream-style alternative.

How can sour cream be made milder?

Use a mild starter and stop the fermentation earlier.

Refrigerate the cream as soon as it has thickened and developed a gentle cultured flavour.

How can it be made more sour?

Allow it to ferment for longer, but check it regularly.

Too much fermentation can cause separation and an excessively sharp taste.

Why does sour cream thicken in the refrigerator?

Cooling firms the fat and helps the fermented structure settle.

Warm cultured cream often looks softer than the finished refrigerated product.

Can sour cream made with lemon juice be recultured?

No. Lemon juice adds acidity but does not provide an active culture.

Only properly fermented sour cream containing living bacteria can be used to start another batch.

Can homemade sour cream be frozen?

It can be frozen, but the texture may change.

After defrosting, it may become grainy or separated. It can still be useful in cooked dishes, but it may no longer have the smooth texture expected from fresh sour cream.

Can supermarket sour cream be used as a starter?

It may work if the label confirms that it contains live cultures and has not been heat-treated after fermentation.

Some commercial products contain stabilisers or too few active microorganisms to produce a reliable new batch.

Is longer fermentation always better?

No. Longer fermentation means more acidity, but it can also lead to separation, graininess and an overly sharp flavour.

The best finishing point is the moment when the taste and texture are right for you.

Questions and Experiences

Cream, starters and fermentation equipment can behave differently, so results may vary slightly between batches. You can ask questions and share your preparation time, temperature and results in our homemade sour cream discussion.

Final Thoughts

Making sour cream at home is not difficult, but it requires a little patience and attention.

The best results come from using fresh high-fat cream, a suitable active starter and a stable fermentation temperature. The cream should be left undisturbed and refrigerated as soon as it reaches the desired taste.

The process is flexible. Stop earlier, and you will have something close to crème fraîche. Leave it longer, and it will become sharper, thicker and more like traditional sour cream.

Once you understand how the cream, starter, temperature and time work together, you can adjust each batch to suit your own taste. That is one of the greatest advantages of making cultured dairy foods at home.