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What is a Pasteurizer?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

A pasteurizer is a device which pasteurizes, treating a food product to kill disease-causing organisms such as bacteria. Milk is one of the most widely pasteurized foods, but pasteurizers can also be used with a variety of other liquids, and some other foods can be pasteurized as well. Pasteurization is used to make food safer, so that it can be sold commercially without concerns that people will get sick when they consume it. People can also pasteurize foods at home when processing foods they have made.

Pasteurizers can work in a number of different ways. One of the most common styles is the high temperature, short time (HTST) or flash pasteurizer, which brings food to a very high temperature for a brief period to kill bacteria before rapidly cooling it. Related is the higher heat, shorter time (HHST) pasteurization method. Pasteurizers can also be used for ultra heat treatment pasteurization, high pressure pasteurization, and extended shelf life pasteurization, which can render foods so stable that they can be stored at room temperature in aseptic containers for several months.

Milk is pasteurized to kill harmful bacteria.
Milk is pasteurized to kill harmful bacteria.

In all cases, a pasteurizer must be kept in good condition. Pasteurizers can handle food in batches or continuously, depending on the design. A batch pasteurizer is a more common option for home use, while continuous pasteurization is used in facilities like dairies, where there is a steady supply of fluid which requires treatment in a pasteurizer. If any part of the pasteurizer becomes contaminated, it can spread organisms to supposedly pasteurized food, and they will breed inside the food, appreciating the lack of competition created by the elimination of microorganisms.

Most milk sold in grocery stores is pasteurized.
Most milk sold in grocery stores is pasteurized.

For industrial pasteurization, a number of companies make pasteurizers, which usually need to be special ordered and may need to be installed by a company technician. These devices are huge and very complex, with a number of monitoring systems which are designed to keep them safe. People are also usually required to monitor the pasteurizer with regular swabs to check for bacteria and other measures which are intended to identify problems before batches of contaminated food are released to the public.

Dairy processing plants are responsible for pasteurization and homogenization of milk to specific standards before it is bottled.
Dairy processing plants are responsible for pasteurization and homogenization of milk to specific standards before it is bottled.

A pasteurizer for home use can be obtained through a kitchen supply store or catalog, or through a store which stocks homesteading supplies. These devices may fit on a stove or be designed to plug into the wall, and they usually pasteurize a limited amount of food. When buying a home pasteurizer, people should find out what the capacity is, and take note of the kind of pasteurization it offers.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AboutMechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AboutMechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

Discussion Comments

anon349842

Can anyone help me about understanding the process of milk pasteurization?

honeybees

I have recently thought about pasteurizing my milk and making some of my own cheese. I have a neighbor who I can buy fresh milk from, but would feel better about pasteurizing it before giving it to my kids.

How hard is it to find a used pasteurizer for sale? I haven't been able to find any close to where I live, but don't know if I am looking in the right places or not.

I imagine this is something that is not too common, but there are probably a lot of used ones out there. Many times people are interested in doing something like this, and then realize it takes up too much time so the machine just sits there and never gets used.

John57

When you pasteurize milk, it is also important to cool it right away when you are done heating it. My favorite way of doing this is to use my electric ice cream freezer. I have found this to be much quicker than the ice water method I used to use.

It also makes the milk really cold, and that is the best way to drink a glass of fresh milk. There is something about a glass of lukewarm milk that kind of makes my stomach turn.

When I started pasteurizing milk, I was lucky enough to find a used milk pasteurizer at a garage sale. I know some of the new ones can cost up to $300, so I felt like mine was really a bargain.

LisaLou

@julies - I think that drinking pasteurized milk is safer than drinking raw milk. Even though I buy my milk from a local dairy farm, I still prefer to pasteurize it when I get home.

I bought a home milk pasteurizer that makes this process very quick and simple. With this unit, you just plug it in to the wall, and it will pasteurize up to two gallons at a time. The key is to make sure the milk stays heated to the right level during the whole process.

This way the milk will also last longer in the refrigerator. It doesn't last as long as the milk I used to buy at the store, but it will usually last up to a week.

julies

Both of my parents grew up on the farm and I enjoy hearing how their life was so different than mine and our kids today.

My dad had a dairy cow they used for milk for their family. From the way he talked, they didn't use any kind of pasteurizer equipment for their milk.

With 6 kids in the family, it didn't last very long and it didn't need to have a shelf life. I am used to drinking pasteurized, skim milk and don't know if I could stomach drinking milk like this.

I know that some people recommend drinking raw milk vs pasteurized milk, but I really don't understand what the advantages would be.

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    • Milk is pasteurized to kill harmful bacteria.
      By: Hyrma
      Milk is pasteurized to kill harmful bacteria.
    • Most milk sold in grocery stores is pasteurized.
      By: vlorzor
      Most milk sold in grocery stores is pasteurized.
    • Dairy processing plants are responsible for pasteurization and homogenization of milk to specific standards before it is bottled.
      By: Budimir Jevtic
      Dairy processing plants are responsible for pasteurization and homogenization of milk to specific standards before it is bottled.