Vegetables à la sous vide

For several years now, we have seen a trend of the equipment found in kitchens coming to resemble more and more that which you would find in a chemistry lab. The use of ultrasonic baths, liquid nitrogen, and freeze-drying (lyophilization) is mostly limited to fancy restaurants where they want to wow you with their methods. That being said, one lab method that has been adopted into the kitchen in recent years, and that is increasingly being used in private homes is “sous vide” cooking.

Sous vide (pronounced su-vid) means “under vacuum” in French. This name refers to a method of food preparation that involves placing food in a plastic bag, which is then sealed and cooked in water at a low temperature for a long time. Funnily enough, the vacuum that we see presented in the name is hardly even an important part of the method; we can’t get much of a vacuum seal in the types of bags we would use for cooking, but we can remove the air with the help of a vacuum. It does not actually require a vacuum, but merely that the food is sealed and thus it does not dry out, nor does the water from the bath penetrate the bag, and that the nutrients and aromas of the food are held in during the cooking. Cooking at low temperatures is advantageous in that it best allows for the preservation of the nutritional value and taste of the food as well as the structure of the items cooked. For cooking vegetables in this manner, we generally use a temperature around 80 degrees Celsius, with a cooking time of about an hour. With sous vide cooking, meat is cooking at temperatures of about 60 degrees for several hours. This is basically the inverse of what happens in a pressure cooker, where we reach temperatures as high as 120 degrees and have shortened cooking times. 

In addition to better preserving the aroma and color, different chemical processes that take place in normal cooking and baking are avoided with the sous vide method. Starch and pectin gelatinize at 80 degrees, but the cell walls remain mostly undamaged, meaning the structure of the vegetables remains firmer.


Recipe, preparation, price

 

Quantity (g or ml)

Price for 4 person (EUR)

Main dish

 

 

Zucchini

200

0,16

Eggplant

200

0,32

Potato

200

0,16

Broccoli

200

0,68

Olive oil

20

0,12

Salt

5

0,00

Peppers

5

0,31

Side dish

Onion

200

0,24

Carrots

200

0,20

Olive oil

20

0,12

Lentils

250

1,45

Poppy seeds

35

0,52

Salt

3

0,00

Salad

Lettuce

250

0,40

Pumpkin seed oil

8

0,10

Vinegar

4

0,02

Salt

3

0,00

Together

4,78

 

 

Zucchini, eggplant, and potato were all cut into slices a couple of centimeters thick and coated with a mixture of olive oil, salt, spices, and a bit of mustard. We then put the vegetables in polyvinyl bags and squeezed the air out by hand since we do not have a vacuum apparatus (meaning we really cooked more à la sous main, but we always like to show that a kitchen does not need a whole range of fancy appliances to make a range of fancy foods!). We took care to ensure that the bags were food safe, even at elevated temperatures, which is an essential step; not just any plastic bag can be used. Due to the differing firmness of the vegetables, we cooked the eggplant and zucchini together in one bag and the potato in another. Both bags were immersed in water, which was heated and maintained at 80 degrees (easiest with a special temperature-regulated bathing device, but even a pot and a thermostat will do).

We left the bag openings above the waterline to make sure we would not have to worry about water leaking in. After an hour of cooking, we tried the vegetables and found they were properly cooked. Even the potatoes were already set to eat after this amount of cooking with this method.

We also prepared a deliciously creamy lentil sauce for the vegetables by cooking finely chopped onions and grated carrots in olive oil. After 5 minutes, we added red lentils and poppy seeds, before adding water and cooking for 15 minutes. We also made a green salad to round out our meal. 

The price of our lunch was less than 5€ for 4 people, coming in at 1.2€ per person. The most expensive ingredient was the lentils, which were about a third of the lunch budget. However, this was a good investment; the lentils made an important nutritional contribution, giving almost half the energy of the meal and 3/4 of the protein.


Nutritional value

With lunch consumed quantity

% From daily needs

Energy

501,7

kcal

25

Proteins

22,5

g

40

Total fats

17,1

g

39

Carbohydrates

70,7

g

 

Starch

39,3

g

 

Sugar

10,8

g

 

Fibers

16,2

g

65

Calcium (Ca)

246,6

mg

25

Iron (Fe)

6,959

mg

70

Magnesium (Mg)

119,1

mg

30

Phosphorus (P)

396,4

mg

57

Potassium (K)

1471,5

mg

74

Sodium (Na)

1150,9

mg

209

Zinc (Zn)

3,661

mg

37

Copper (Cu)

0,837

mg

93

Manganese (Mn)

2,3

mg

100

Selenium (Se)

3,634

µg

7

Vitamin A

671,3

µg

67

Vitamin E

4,192

mg

28

Vitamin D

0

µg

0

Vitamin C

79,8

mg

80

Thiamin (B1)

0,839

mg

65

Riboflavin (B2)

0,375

mg

25

Niacin (B3)

3,901

mg

27

Pantothenic acid (B5)

2,342

mg

39

Vitamin B6

0,907

mg

60

Folic acid (B9)

412

µg

103

Vitamin B12

0

µg

0

Vitamin K

152,6

µg

218

 

With today’s lunch, we got our usual 25% of our daily caloric requirements, while also getting more than 40% of our need for protein. We consumed almost all other nutrients in quantities relatively higher than for calories – as you can see in the table, we got lots of iron (70%), vitamin A (67%), folic acid (100%), vitamin C (80%). We also managed to get as much as half of our daily requirement for calcium with poppy seeds, despite having used less than 9 g per person. Carrots are known for their high vitamin A content, and today they provided as much as 2/3 of this vitamin in our meal, though even without the carrots we would have consumed enough vitamin A with this meal!

As usual, we did not consume vitamins B12 or D with this meal as these are not found in unfortified vegan foods and are why many vegans take daily vitamins.

If you have questions about today’s lunch (or ideas for future lunches) then feel free to write to us at info@hungry-pumpkin.com and we will get back to you!

Have a great weekend!

-The Hungry Pumpkin Team

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