In this brief guide, we will answer the question, can you boil soy milk? We will discuss some reasons to avoid boiling soy milk. We will discuss how soy milk is produced at the industrial and domestic levels and the role that heat plays in soy milk production.
Can you boil soy milk?
You can boil soy milk, however, it compromises the quality of the milk. If you want to retain the taste and flavor of soy milk, you must avoid boiling soy milk and use mild heat only. Soymilk can be heated without affecting the taste or quality of milk.
Excessive heating causes adverse effects on the nutritive value due to the destruction of certain essential amino acids (e.g., lysine and cysteine) and vitamins (e.g., thiamin). Severe heat treatment may also result in development of brown color and cooked flavor in the soy foods (1).
Boiling soy milk with beans is an important step in the production of soy milk as it helps blend and exploit the flavor of soybeans. However, heating for long periods gets rid of the amino acids that are important as a nutritional source.
A 2017 report by Research and Markets stated that the bovine milk alternative beverage marketplace accounted for around $6 billion in total US retail market sales in 2016 (25% of the total US dairy and milk alternative beverage industry). The same report projected that the milk alternative beverage industry would reach $28 billion in total US retail market sales by the year 2021 (2).
Is it crucial to heat soy milk?
The heating of soy milk is done at 100 C for 10- 30 minutes. Stirring is an important step while the soybean slurry is being heated for a maximum of 30 minutes. Studies showed that cooking soy milk at 110°C gave nutritionally richer and microbiologically safer products, however, cooking at 100°C for 30 minutes gave soy milk that was most acceptable to consumers (3).
Heating helps to inhibit the trypsin enzyme which improves the flavor and nutritional value of milk. Heat also helps to get rid of the bacteria and prolong the shelf-life of soy milk. It has been shown that heat inactivation of antinutritional factors such as trypsin inhibitors parallels the nutritive value improvement of the soy protein (1).
Heating not only exploits the flavor from the beans but gets rid of the enzyme called lipoxygenases which gives beans its distinctive taste. As the soymilk resembles more cow milk than soybeans, it leads to a greater acceptance of the product.
Lipoxygenases catalyzes the oxidation of polyunsaturated fatty acids during soaking and grinding of the soya milk processing. The products from the oxidation are conjugated unsaturated fatty acid hydroperoxides and these can be easily degraded into volatile compounds, such as hexanol, trans-2-nonenal, 1-octen-3-ol, trans-2, trans-4-decadienal, 2-pentylfuran, 1-octen-3-one, and trans-2, trans-4-nonadienal, to cause beany flavor in the soya milk (4).
Heating the soy milk also gets rid of the odor that is disliked by people who consume soy milk. As the enzymes are denatured with heat, the taste and smell that soybeans bring are combatted.
How to make soy milk at home?
You can make soy milk at home if you run out of it. To make soy milk, you need white soybeans, a blender, and a milk bag, Instead of a nut-milk bag you can use a muslin cloth.
At the soymilk plant, a simple process allows the production of this drink that closely resembles dairy milk. First soybeans are soaked in water overnight and then grinded with a fresh batch of water. After the mixture is blended uniformly then it is put to boil.
Homemade soymilk is fresh and is free of additives and preservatives, hence, make a healthy drink.
The traditional orient processing of soya milk involves four main steps, which are (1) soaking the beans, (2) grinding in water, (3) filtering to remove the residue, and (4) cooking. The soya beans need to be soaked in water overnight to soften the bean. The soaked soya beans will be ground with water until a slurry is formed and then filtration is done to separate the raw soya milk from the solid residue, i.e. okara. The raw soya milk required to be cooked for a few min before consumption. This step helps to prolong the shelf-life, improve the nutritional value, and improve the protein digestibility (4).
Follow the steps below to make the soymilk at home;
- Soak the soybeans in water
To make soy milk you need to soak white beans overnight in 2-3 cups of water. Let the beans soak at room temperature for at least 8 hours. The beans take up the water and increase in volume about three times.
The next day, drain the water away from the beans and rinse.
- Steam or boil the soybeans
You can also choose to take the skin of soybean off. After the soybeans have been peeled, you can add 4 cups of water and boil.
Let the soy milk simmer at 100 celsius for 20 minutes and stir to prevent clumping. Then you need to heat the soy milk to a boiling temperature on medium flame.
You can also use steam to cook the soybeans instead of boiling them directly. To use steam you will need a steamer.
First, bring a few inches of water to a boil and then place a steamer basket into the pot. Transfer the beans into the insert, cover, and let the steam cook the beans for an hour. The beans will become tender and you might need to add more water.
- Blend and strain the mixture
Blend the soy milk until you get a smooth creamy mixture.
Then strain to get rid of the particles. Use the tight-weave cloth to strain the milk and remove the particles. When you strain the soy milk, you get rid of the okra or the dispersible fiber residues.
After the milk cools down, you can use it immediately or store it in the refrigerator for 4 days. Other methods that make a part of soy milk manufacturing are homogenization, pasteurization, sterilization, or aseptic packaging.
The packaging is an important reason why store-bought soy milk lasts long relative to homemade.
The soy milk you buy from the supermarket is sometimes flavored. If you like you can also flavor the soymilk with a sweetener such as nectar, honey, maple syrup, or sugar.
Other FAQs about Milk that you may be interested in.
In this brief guide, we answered the question, can you boil soy milk? We discussed some reasons to avoid boiling soy milk. We discussed how soy milk is produced at the industrial and domestic levels and the role that heat plays in soy milk production.
- Kwok, Kin-Chor, Han-Hua Liang, and Keshavan Niranjan. Optimizing conditions for thermal processes of soy milk. J agric food chem, 2002, 50, 4834-4838.
- Chalupa-Krebzdak, Sebastian, Chloe J. Long, and Benjamin M. Bohrer. Nutrient density and nutritional value of milk and plant-based milk alternatives. Int dairy j, 2018, 87, 84-92.
- ¹J, K. Ikya, et al. Effect of cooking temperature on some quality characteristics of soy milk. Adv J Food Sci Technol, 2013, 5, 543-546.
- Chong, WK., Mah, SY., Easa, A.M. et al. Thermal inactivation of lipoxygenase in soya bean using superheated steam to produce low beany flavour soya milk. J Food Sci Technol, 2019, 56, 4371–4379.