Task 109: How to Purée Vegetables

Estimated Time: 9 mins

The most important aspect of preparing puréed vegetables is to cook them properly so they can be broken down easily into a smooth purée. No matter what cooking method you choose to use the biggest mistake cooks make is not cooking the vegetables until they are fork-tender.

Cooking in Liquid
The most common way to cook the vegetables is by simmering them in a flavorful liquid. For quick-cooking and to maintain the integrity of the vegetables, cut them into small pieces. Add liquid to cover, along with any aromatics, bouquet garni and salt to season. Cover the pot and quickly bring the mixture to a boil, then lower the heat to maintain a simmer. When working with green vegetables, bring the water to a simmer first, then add the vegetables.

Once the liquid comes to a boil, reduce the heat so the vegetables simmer and cook until done. If the vegetables are cut into small uniform pieces, this process will take just a matter of minutes. Be sure to test a few pieces for doneness.

Sweating
Alternatively, you can first sweat aromatics in some fat to bring out their flavor even more. Add the vegetables and sweat until they just begin to soften. Remember that the technique of sweating is performed over low heat and is not intended to add color to the vegetables at all – it just softens and brings out flavors using gentler heat than sautéing. Adding a hot liquid – just to cover – will speed up the cooking time. Bring the contents to the boiling point and then simmer until done.

Other Methods
You can also roast or steam the vegetables. Roasting adds color, which may or may not be desirable. In some cases you may want to limit how much coloration is achieved if you want to maintain a particular vibrant coloration in the final product. Vegetables that are roasted tend to add a darker or browner overall hue to the purée.

Steaming has the advantage of maintaining nutrients and color, but may require some form of liquid to help purée and thin out the mixture. The steaming liquid may be suitable for thinning out the purée. On the other hand, vegetables with a light flavor, such as Russett potatoes, may become watery in flavor with the addition of water. Instead, milk or other flavorful liquid may be best.

Braised vegetables can also be puréed. Bear in mind, however, that the mirepoix, once puréed, will likely change the color of the sauce that the dish was cooked in. Braising helps build tremendous flavor and complexity in a dish.

Regardless of the method used to cook the vegetables, they must be cooked through until they are tender enough so they will be smooth. Keep in mind that overcooked vegetables, may not only become waterlogged, but they will lose many nutrients. Depending on the vegetable, they can also lose much of their color and flavor.

As an example, green vegetables, which contain chlorophyll, are best cooked until tender and then shocked in an ice bath in order to set their color. Once this is done, they can then be puréed to the desired consistency.

When the vegetables have been cooked until very tender, they are ready to be puréed. You always want to be in control of the purée’s final texture, so, if the vegetables were cooked in a liquid, first strain them.

Note on Texture & Consistency It is better to start thick and then thin out the purée as needed with the cooking liquid. If you commit to using everything right from the beginning, you can accidentally wind up with a purée that is far too thin.

Equipment & Tools
Various types of equipment can be used to purée vegetables. Handheld blenders, food processors and blenders (especially hi-speed blenders) are very efficient. However, with high starch vegetables, these machines tend to over-process the food and make it gluey. Mashers, ricers and food mills work very well. Food mills are especially useful for ingredients that are already soft in texture and do not need much processing. Mortar and pestles can also be used. A drum sieve, also called a tamis, can be used to create an extremely smooth texture. Very thin purées can be passed through a fine strainer but keep in mind that if all of the solids are strained out, the remaining liquid can be overly thin and have no texture.

If using an electric device, make sure to add a bit of liquid as you process to keep the contents moving. You may need to scrape the sides down periodically to ensure everything is getting broken down evenly. If using a mechanical device, first process the vegetables and then add the liquid once the vegetables have been fully puréed, but being careful not to overwork them.

The purée can be left as-is for more mouth texture; however, for very silky results, it can be passed through a fine strainer to remove any fibers.

The purée is then returned to an appropriate-sized pot for some finishing steps. The final texture depends on the dish you are making, so if you need a thinner purée, simply adjust with a bit more liquid. At this point, additions such as cream, butter, olive oil or even a bit of melting cheese can be added for richness. The purée can then be further flavored by stirring in some fresh herbs, ground spices or condiments. Always make sure to taste and properly season the purée.

No matter what the consistency of the final purée, all vegetable purées should maintain their dominant flavor and color.