Soy milk; fridge vs. shelf?
Occasionally, I see a product in the supermarket that is either sold off the shelf at room temperature (then expected to be refrigerated after opening), or right out of the fridge. I use soy milk as an example, but there are other products that fit the bill as well (though the only other one that comes to mind is almond milk). What's (most likely to be) the difference between a product sold refrigerated and its equivalent sold room-temperature?
Best Answer
I'll use (cow) milk as an example, but the idea is the same for other products like juices and fake milks.
In the case of milk, the milk you get in tetrapak cartons (shelf stable milk) is ultra-high temperature pasteurized (UHT). It is heated briefly (1 to 2 seconds) to over 135 C then cooled down very quickly to kill bacteria and spores and then filled into a sterile container (the entire system is designed to keep bad organisms out, so the result remains sterile). This gives a much longer shelf-life than fresh milk (but once opened, it should be refrigerated), on the order of months. In contrast, the usual method of pasteurizing milk (at least in the US (*); Europe does a lot more UHT) is pasteurized by heated to about 70-75C for 15-30 seconds, then chilled and packaged (and lasts on the order of days).
The flavor can be affected due to things like the Maillard reaction occurring. Also, the temperature can affect the uses of the milk for applications like cheese making affecting the proteins.
(*) This is dependent on the type of milk you get; organic cartons in the US you find in the refrigerated section are often UHT pasteurized.
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Quick Answer about "Soy milk; fridge vs. shelf?"
Does Soy Milk Need to Be Refrigerated? Soy milk, once opened, requires refrigeration and should be consumed within five days. Prior to being opened, however, soy milk actually doesn't require chilling, and has an unrefrigerated shelf life of at least one year.Does soy milk need to be kept in the fridge?
Does Soy Milk Need to Be Refrigerated? Shelf-stable soy milk can sit on the counter until you open it up. After opening, you should store it in the fridge. Refrigerated soy milk, as the name suggests, requires refrigeration at all times.Is refrigerated soy milk shelf-stable?
Both types of soy milk must be refrigerated once opened, and typically last 7-10 days in the fridge. Before they're opened, the expiry date on the carton is a good indicator of its shelf life. Products often stay fresh after 10 days, but it cannot be guaranteed (this is when the look and smell test comes in handy).Is shelf-stable soy milk bad?
The shelf-stable soy milk has more Vitamin D and calcium but less Vitamin B12 and Vitamin A. It's important to keep in mind that this is also just for one particular brand.What is the difference between refrigerated soy milk?
There are two types of soy milk available on the market: refrigerated soy milk and shelf-stable soy milk. The main difference between the two is packaging. The shelf-stable variety is treated with ultra-high temperature (UHT) to extend its shelf life and sold in aseptic containers.HOW TO MAKE DELICIOUS SOYA MILK (SOY MILK) FOR SALE | PRESERVATION | DIFFERENT FLAVORS | PACKAGING
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Answer 2
For milk-alternatives, they're typically the same product (there may be exceptions), but they're often sold chilled for the following reasons:
Marketing: Chilled products are typically perishable foods and therefore perceived to be fresher and of higher quality. Consumers will usually make the same assumption for any product sold chilled.
Familiarity vs. regular milk: As soya-milk is usually consumed as a replacement for dairy, by selling it chilled it's perceived to be more similar to milk - thus making the choice as an alternative less of a "risk".
Convenience: Most people prefer using chilled soya-milk, so when sold chilled it's more ready for use.
Familiarity when shopping: Customers are used to going to the chilled section to buy milk.
This can be verified by looking at the storage instructions on the carton, which will be the same as most foods sold at room temperature: "Store in a cool dark place, refrigerate once opened".
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
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