Pasteurization is the process of heating a food – usually a liquid – to a specific temperature for the purpose of slowing microbial growth, extending the shelf life of a product by slowing the spoilage process. The technique was first developed to prevent wine and beer from souring quickly, but it is very widely used today with dairy products because pasteurization actually halts the growth of potentially harmful bacteria in milk. In pasteurization, milk is heated to a temperature of 161Â°F for 15â€“20 seconds, then quickly chilled to 40Â°F or lower. The target temperature for pasteurization is below the boiling point of milk because milk will curdle if it boils.
The label “ultra pasteurized” also appears frequently in the dairy aisle, primarily on cartons of heavy cream and half and half. These products are subject to an ultra high temperature (UHT) pasteurization process where they are heated to at least 275Â°F for a very short period of time. Ultra pasteurized dairy products (the process is used for many products, including juices, etc.) have a much longer shelf life than their pasteurized counterparts because the process eliminates a much larger percentage of bacteria than regular pasteurization does.
In general it does not matter if you use pasteurized or ultra pasteurized in a recipe that calls for milk or cream and there is virtually no nutritional difference between the two. That said, since cream is the product subject to UHT more frequently than milk (in the US, this is the case, while in many other parts of the world UHT is common with milk products to make them shelf-stable without refrigeration for several months), it is worth noting that there can be some small drawbacks to it. UHT can impart a slightly cooked taste to dairy, which might not be noticeable in a baked product but can be detectable in whipped cream. The ultra pasteurized heavy and whipping creams also do not whip up quite as well – although they still will whip up to a fluffy cream – as their pasteurized counterparts and seem to take slightly longer to do so.
HeatherSeptember 9, 2010
From the end user perspective the big difference seems to be for specialty applications. You can’t use the ultra pasteurized dairy to make clotted cream, creme fraiche, and usually cheese. They just won’t set up.
LucySeptember 10, 2010
Very good to know. Thank you.
NinaSeptember 10, 2010
Thanks for the explanation. I’ve wondered what the difference was but never got around to looking it up.
BTW, “pasteurized” is spelled incorrectly in your title. Thought you’d want to know. 🙂
Have a great weekend!
DessertForTwoSeptember 10, 2010
Thank you so much for this! I’ve noticed baking recipes calling for non-pasteurized heavy cream lately and I’ve been wondering why!
Thanks again 🙂
NicoleSeptember 10, 2010
Dessertfortwo – Very interesting! I wonder if they mean raw – as in unpasteurized – cream? I’ve used it before, but because it can spoil easily it is one of those things that you should be careful when using. People who use raw milk/dairy also generally recommend being very familiar with your supplier when you use/buy it. Any baking recipe (cakes, etc.) that calls for nonpasteurized cream can also be made with regular pasteurized cream.
EricaSeptember 11, 2010
Thanks for the information. I have often wondered exactly what the temps were for pasteurized and ultra-pasteurized but just never took the time to Google it. Thanks.
shandraOctober 4, 2013
Thanks so much for this information. I just found your site and I’m hoping the information here will help me with my baking projects as now I live in Mexico and no longer in the USA. Here in this part of Mexico at least, the only kind of cream is ultra pasteurized which is shelf stable so I understand and also something called Chantilly cream. I am trying to figure out how to use these ingredients so that I can get back to my love of baking. Another thing is here I can’t seem to find cake flour only all purpose which is very soft. Once again thanks for the information and I can’t wait to peruse your site.