How To Thicken Sauces, Soups & Stews

One of the many problems I see budding chefs, or home cooks have while cooking is how to thicken sauces, soups, stews, and other liquids. A basic, yet essential skill to have as a cook, knowing which ingredients  to use to produce a thick, creamy consistency can be confusing. In the following guide, I'll cover which ingredients can be used to thicken various dishes, when to use them, and how!

There are so many ingredients and methods available to a cook in order to thicken liquids, that it can be difficult to list them all. If you have a favorite ingredient/method you use that's not listed below, please let me know in the comments and I'll add it to the list!

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Why Do You Need To Use Thickeners?

Let's start with the very basics first. Why thicken sauces, soups, stews, and desserts at all? The simple answer is mouth-feel, or texture! Texture is just as an important part of eating food as flavor is. We expect certain foods to have a certain texture or mouth feel to them, and it can influence if we perceive a dish to be "good" or "bad".

Texture also adds variety to dishes, and subconsciously makes the food we eat more interesting and fun to eat. Some recipes simply HAVE to be thickened in order to work out. A fruit pie is a good example. If the filling is not thickened prior to baking, you end up with a beautifully crisp crust filled with liquid. Not something that is easy to eat, or enjoyable for that matter.

So What Ingredients Can I Use As Thickeners?

This is where things become a little complicated. There are many items that posses thickening properties, but not all are suitable for every recipe. We'll start with the traditional, and more commonly used items, and make our way to more modern techniques.

Thickening foods takes practice, and the following guide will help you to create thickened foods that:

• have a good flavor and are not pasty or floury
• are smooth and clear of lumps
• have a consistency that will coat the back of a spoon

Using Starches As A Thickening Agent

Starches thicken foods through the gelatinization of the starch granules as they absorb moisture in a liquid and are heated. Starches are an odorless, tasteless ingredient derived from plants such as potatoes, various grains and cereals. They include:

• potatoes
• corn
• rice
• wheat
• arrowroot
• and oats

Starches are most often sold in a powder form, such as flour, corn starch, or potato starch. They usually need to be mixed into another ingredient such as cold water, or a fat to prevent them from clumping in the hot liquid they are added to. Veloute sauce is thickened with a starch, as is bechamel sauce.

Some vegetables do contain a lot starch and can be used to help naturally thicken recipes such as purees by simply cooking them down with water until they thicken on their own. - Chef Markus

Using A Slurry

All starches can be made into a slurry before using them to thicken liquids. This means mixing the starch with some cold water and dissolving it before adding it to the liquid to be thickened. Once a slurry is made, the starch is added to the hot liquid, and gently cooked to activate the thickening properties. 

As the liquid is cooked with the slurry, the starch swells and forms a gel that binds and thickens the food.

Whenever you use a starch to thicken a liquid, it is important to bring the liquid to a boil after adding the starch slurry to the mix. This allows it's thickening properties to properly do their job. Some starches such as flour, need to be cooked for longer periods of time, (up to 30 minutes), to 'cook out' the starchy flour flavor and fully activate it's thickening power.

Making A Roux

Roux is the traditional French way of thickening sauces, and some soups. Essentially a roux is a mixture of equal parts flour, and butter by weight. It's important to note that a roux is always weighed out, and never measured. This is because 1 cup of flour, and 1 cup of butter, are not actually equal when weighed out. A good rough should be stiff, and not runny.

To make a roux, the butter is first melted, at which point the flour is added to it. The roux is then cooked further to produce either a white roux, blonde roux, or brown roux. Keep in mind that the longer a roux is cooked (ie: a brown roux) the more it will loose it's thickening power.

The starch content of different flours can also impact how strong your roux is. Bread flour for example is high in protein and low in starch, making it a poor choice for use in a roux. Cake or All purpose flour are both fairly high in starch and make an excellent roux.

As a general rule of thumb, room temperature roux is added to hot liquids or, hot roux is added to room temperature liquids. This prevents the roux from clumping in the liquid. - Chef Markus

How Much Roux Do You Need To Thicken A Liquid?

At minimum you need 100 grams of roux to thicken 1 liter of liquid. To create a thicker consistency, you can increase the amount of roux to 150 grams or 200 grams per liter.

Beurre Manie

Very similar to a roux, beurre manie uses flour and room temperature butter to create a thickening agent. Where a roux is measured in equal parts flour and butter by weight, beurre manie is measured by volume.

To make a beurre manie, measure out ½ cup of flour and ½ cup of softened butter. The flour and butter are then kneaded together and then formed into little balls.

A beurre manie is traditionally used to thicken soups and sauces at the end of the cooking process, or to quickly adjust the consistency right before serving. It will add a light shine to sauces as it melts, making it great for thickening espagnole sauce and other gravies right before serving.

Using Eggs As A Thickening Agent

A traditional method of thickening liquids that does not use a starch are eggs. Eggs thicken foods by coagulating, and care must be taken not to heat them to quickly to prevent the eggs from curdling. Desserts such as custards, cream sauces, creme brulees, and ice cream all use tempered eggs as a thickener.

Savory dishes such as sauces and soups, can be thickened by using a liaison. While a liaison does slightly thicken, it mainly adds richness, and smoothness to soups and sauces.

Tempering Eggs

The most common method of using eggs to thicken foods, (especially desserts) is by tempering them, although some recipes such as pumpkin pie use whole eggs as a thickener as the product is cooked or baked.

Tempering refers to the action of slowly adding a hot liquid to eggs to raise their temperature without curdling them. This can be done with liquids such as an Alfredo or other cream based sauce, or with a creme brulee or ice cream base.

To temper eggs:

1. Start by whisking the eggs in a bowl.
2. Bit by bit add the hot liquid (ie: your sauce or ice cream base) to the eggs while whisking them to gradually raise the temperature of the eggs.
3. Once the liquid egg mix is hot, it can be whisked into the liquid to be thickened.

Using A Liaison

A liaison is almost identical to using tempered eggs, but with the addition of heavy cream. A liaison is used to thicken savory soups and sauces while adding a smooth and rich texture to the end product. A liaison actually uses the tempering method describes above to heat the eggs before the egg and cream mixture is added to the hot soup or sauce.

By adding cream to the eggs before tempering, you raise the temperature the eggs coagulate at, reducing the chance of curdling the eggs. To thicken 1 liter of liquid you need 2 egg yolks and 2 fl. oz (60 ml) of cream.

To make a liaison:

1. Whisk together 2 egg yolks and 60 ml (or 4 fl. oz.) of heavy cream. Milk can also be used but cream will add a richer texture.
2. Gradually temper in the hot liquid to be thickened, and temper the egg mixture as described above.
3. Once the liaison mixture is hot, it can be stirred back into the soup or sauce top thicken it.,

Modern Thickening Agents

There are many modern refined ingredients that can be used to thicken foods as well, and many of them are used commercially in sauces, jams, and dressings, because they are very stable, have a long shelf life, and don't add any color or flavor to the finished product.

Some examples are:

Pectin

A naturally occurring fiber found in most plant cells, pectin is produced on a commercial scale for use in thickening foods, medications, and sweets. Most commonly associated with use in jam making, pectin helps gel jams, marmalade, and jellies, which would otherwise have a sauce like consistency.

Agar Agar

Agar Agar is made from a various types of red seaweeds, and is popularly used in Asian cuisine to thicken desserts, sauces, and preserves. It is similar to gelatin, and is often used as a vegetarian alternative, though it gives a much firmer texture then gelatin once set.

To use Agar Agar dissolve the agar powder or agar flakes in warm water and then mix it into whatever you are thickening. Bring it to a boil before chilling to allow it to set.

Xantham Gum

Xantham gum is a polysaccharide made by fermenting sugar with a specific bacteria (from which it gets its name). It is most often sold in powder form, and is very commonly used in the commercial food industry to thicken any liquid food. It also acts as a preservative making it a popular food additive.

To use xantham gum, dissolve the xantham powder in water (in a 2:1 rato) and then stir the liquid into you soup, sauce or other food. The xantham gum will create a gel like texture.

Guar Gum

Also called guaran, guar gum is extracted from guar beans and has stabilizing and thickening properties. Just like xantham gum, guar gum is gluten free, making it a popular choice as a thickening agent in gluten free recipes. It is used commercially to thicken dairy products such as, milk, yogurt, and ice cream. Guar gum is used to substitute wheat flours in baked goods due to it's gluten free nature.

Guar gum is most often sold in powder form, and is used much like xantham gum. To thicken dressings, smoothies, or other liquids, simply dissolve a pinch of the guar gum in water and then add it to your recipe. Start with just a pinch, because a small amount of guar gum can thicken quite quickly.

Guar gum is unique in that it does not need heat to thicken, and will gel on its own after being dissolved in liquid. This makes it great for stabilizing and thickening salad dressings, ice creams, jello etc.

Gelatin

Just as pectin is naturally occurring in plant cells. Gelatin, is naturally found in collagen (the connective tissues of animals), and is easily extracted through boiling. This is easily demonstrated when making chicken or beef stock at home. Once cooled the stock gels due to the high gelatin content.

Commercially, gelatin is most often used to thicken desserts (such as panna cotta) and various sweets such as gummy bears, and other fruit snacks. It is also used in dairy products such as yogurt and various cheeses.

Most often gelatin can be purchased as sheet gelatin or powdered gelatin. Sheet gelatin needs to be soaked in cold water for 5 to 10 minutes, after which it is gently wrung out, and then added to various recipes as needed. Powdered gelatin is sprinkled into cold water, and also left to sit for 5 to 10 minutes, after which time it creates a spongy texture. The 'bloomed' gelatin powder is then poured into warm or hot liquid to fully dissolve.

Reducing Liquids To Thicken

Besides using various ingredients to thicken sauces, you can also opt for the oldest trick in the book.

Reducing. 

Reduction refers to the process of slowly simmering or boiling a sauce, soup, or other liquid in order to thicken and intensify the flavor by reducing its water content. 

While it is the most time consuming method of thickening foods, reducing has the benefit of not requiring any extra ingredients, as well as automatically intensifying naturally present flavors. Care needs to be taken when reducing dairy based liquids, since heating them to high can result in the liquid splitting, and the fat separating.

If you've made it this far, you can tell that thickening sauces and other foods can be quite a complex task with varying methods and ingredients available to the home cook. 

Did this guide to thickening sauce and other foods help you out? Comment & Rate the guide below, then take a picture and tag me on Facebook & Instagram: @earthfoodandfire . For more from scratch recipes follow me on Instagram & Pinterest!