How Well Do Beer Thermoses Work?

Beer lovers often wonder if they can use a thermos to keep their drink cold and carbonated on the go. The answer is yes, you can put beer in a thermos, but there are some things to keep in mind. Modern thermoses are usually made from stainless steel, which is non-reactive to beer and can handle the pressure from carbonation. However, if you have an older thermos with a glass interior, the pressure could potentially crack the glass, so it's best to avoid putting beer in a glass thermos. While a thermos can keep your beer cold, it might alter the taste, and it's important to clean it thoroughly afterward to prevent mold growth. Additionally, some establishments may be reluctant to fill a thermos with beer due to legal restrictions and concerns about carbonation and product quality.

Beer in a thermos can stay cold for 3-6 hours, or even 12-24 hours with whiskey stones

However, if you are looking for a way to keep your beer cold while camping or backpacking, there are some creative solutions that you can try. One popular method is to use a river or stream to keep your beer cold. Simply tie a bag of beer cans to a rock and place it in a shaded area of the river bank. This will bring the temperature of the beer down to a fairly cool temperature in about an hour. Another option is to use insulated bottles, such as those made by Coleman or Stanley. These bottles can keep your beer cold for a few hours, but they are heavier to carry while backpacking.

If you are looking for an even longer-lasting solution, consider using whiskey stones in your thermos. Whiskey stones are small cubes, usually made of stainless steel or soapstone, that you freeze before placing in your drink to keep it cold. When used in a thermos, whiskey stones can keep beer cold for up to 24 hours. Just be sure to follow the manufacturer's instructions for safe use and cleaning of the thermos, as proper care will help extend the life of your container.

Additionally, it is important to note that extreme heat, such as temperatures above 80 degrees, can ruin beer. So, if you are camping or backpacking in a hot climate, be sure to take extra precautions to keep your beer cool and stored in a shaded area.

Beer is safe to store in a stainless steel thermos, but not in a glass thermos, which could break from the pressure of carbonation

Most modern thermoses are made from stainless steel, which is the same or very similar metal that beer kegs are made from. Beer is non-reactive to stainless steel, and the metal is strong enough to withstand the pressure from carbonated beer. The pressure from carbonated beer is relatively low (10-20 psi), and stainless steel thermos bottles can handle much higher pressures than this (around 200+ psi). Therefore, stainless steel thermoses are a safe and effective way to store beer and keep it cold and carbonated all day.

However, some thermoses are still made with an interior of glass, which is extremely thin and fragile. The pressure from the carbonation in the beer could potentially be enough to crack the thin layer of glass and break the thermos. Therefore, it is not recommended to store beer in a glass thermos.

In addition, alcohol can potentially leave a lingering taste or odour in the container, and research suggests that ethanol might influence the structure of stainless steel, increasing its susceptibility to corrosion. Therefore, it is generally best to stick to the manufacturer's suggestions and continue storing alcoholic beverages in glass.

The carbonation from beer may make a thermos lid harder to open, but this is usually not an issue

Beer can be safely stored in a stainless steel thermos flask. The beer will stay cold and carbonated for hours, and it won't cause any damage to the thermos. However, the carbonation from the beer may cause a build-up of pressure inside the thermos, which can make the lid harder to open. This is because the pressure pushes the lid up, increasing the friction on the threads. Usually, this is not an issue, and there are several ways to overcome it. One method is to push down on the lid before turning it. Alternatively, if your thermos has a push button, you can vent the pressure before opening.

The pressure from carbonated beer is relatively low, typically ranging from 10 to 20 psi. Stainless steel thermoses can handle much higher pressures, approximately 200 psi or more. For comparison, a plastic Coke bottle can withstand pressure up to around 200 psi before breaking, and stainless steel is significantly stronger. Therefore, the carbonation in beer is unlikely to cause any issues with the thermos itself.

However, it is important to note that some thermoses are still made with an interior of glass. While beer is non-reactive to glass, the pressure from the carbonation could potentially crack the thin glass layer. If you have a glass thermos, it is recommended to leave the lid slightly open to release the pressure and prevent a build-up that could lead to cracking. As a result, your beer will become flat relatively quickly, and there is a risk of leakage during transportation.

Thermoses are not recommended for carbonated liquids, dry ice, or oily liquids

Additionally, the acid in carbonated drinks can react with the stainless steel of the thermos, causing the beverage to deteriorate and taste bad. It can also cause the steel to oxidize and rust, shortening the thermos's lifespan. Furthermore, carbonated drinks can cause the migration of heavy metal elements such as chromium, nickel, and manganese, which can be harmful to health.

As for dry ice, it may be that the thermos cannot handle the extremely low temperatures it produces. Oily liquids, on the other hand, can wear down the seal of the thermos and are challenging to clean. Therefore, it is best to avoid using a thermos for these types of substances and stick to non-carbonated, non-oily liquids at moderate temperatures.

A thermos can alter the taste of beer

Even if your thermos is made from stainless steel, there are still risks associated with storing alcohol in it. Research suggests that ethanol can increase the susceptibility of stainless steel to a specific type of corrosion called "pitting," which creates deep cavities that can weaken the material. This could potentially cause metals like chromium and iron to leech into your drink, which can be harmful if ingested in high amounts.

Furthermore, the carbonation in beer can build up pressure inside the thermos, making the lid more difficult to open. This is usually not an issue unless the beer is left in the thermos for days. However, if the thermos has an interior made of glass, the pressure from the carbonation could potentially crack the glass.

Therefore, it is generally recommended to stick to the manufacturer's suggestions and store alcoholic beverages in glass containers rather than in a thermos.

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