The internet source for discussion and knowledge on pasteurization equipment, technology, and equipment selection for flash pasteurization, tunnel pasteurization, and used pasteurizers.

Typical Pasteurization PU Values for Beer and Juice Products

Thursday, July 23, 2009




Pasteurization values can vary depending on points of measurement in the package and if the PU's are considered to begin accumulation at 120 or 125 degrees F. Under pasteurizing fails to neutralize yeast and flavor changing enzymes, over pasteurizing tends to degrade flavor and nutrients in the product.

All forms of pasteurization are considered compromise between "boiling" (considered sterilization) and no treatment. In addition to pasteurization consideration should be given to the discharge temperature of the package when considering a new or used pasteurizer.

UltraLight Lagers are considered to have been filtered to below the 2 micron level which removes larger particles (including yeast) from the product.

Pasteurizers should achieve three main objectives:
  1. The process of pasteurization
  2. Achieve a discharge temperature suitable for downstream operations
  3. Provide a consistent treatment to all products such that equal flavor properties are achieved across all production

What's Wrong With Flash Pasteurization? The Topics of Stoppage, Flavor and Product Waste

Thursday, July 9, 2009


We have all heard that flash pasteurization treats the product but not the package. Flash pasteurization is not always what it's sold to be, and in many cases only half the facts are considered.

A flash pasteurizer generally needs to start and stop during production. Even if the flash unit has a downstream buffer tank, it will fill periodically during which time the flash pasteurizer needs to stop. In order for the flash unit to "cease production" there are only two options:

1. The flash unit will recirculate product
2. The product is chased out of the flash unit with water, which is recirculated

Both scenarios have effects which need to be considered. In scenario #1 when a product is recirculated through the flash pasteurizer during a stoppage, the amount of product being recirculated (generally 50 liters depending on the size of the flash unit, recirculation pipe etc) is treated and retreated over and over. This product is then generally dispatched downstream to packaging. Even if the product is then mixed in a buffer tank where it is diluted, it is still a relatively large amount of product. This takes away from the argument that flash pasteurization lessens flavor impact.

In the event that the product is chased out with water, there is product which is sent to drain each time the flash unit starts and stops. Like many situations, the overall efficiency of the downstream operation then becomes a key factor in the justificaiton of the equipment, and this product waste needs to be considered.

Particularly in the case of small packaging operations the product waste can accumulate over time and product waste is generally an unforecasted cost of flash pasteurization. This is where the "turn down" ratio of a flash unit becomes important. This feature allows the flash unit to run slower as the downstream buffer tank fills and is available only with variable speed units which come with other controls challenges to ensure that all product is proprerly pasteurized.

Reference other articles in this blog relative to energy impacts and other unforeseen costs associated with flash pasteurization.

Consumption of Flash Pasteurized Products During Pregnancy

Wednesday, July 8, 2009


We receive inquiries from pregnant mothers who have written in attempting to understand if the products (mostly juices and ciders) marked "flash pasteurized" are fit for their consumption.

The difference between "Pasteurization" and "Flash Pasteurization" is straight forward and something all of us can understand. A product that is "pasteurized" has been pasteurized in the bottle after it has been filled. This indicates that both the product and the container were pasteurized together, and is the safest form of pasteurization.

"Flash Pasteurized" products were pasteurized in the pipe prior to filling. This indicates that the juice was pasteurized prior to being put into the bottle and having the cap applied. For information on pasteurization and eggs or pasteurization and raw milk - click here.

If you have a favorite juice which is "flash pasteurized" it is likely fine. You are trusting that the bottle and cap were clean and the required precautions were taken.If you are not comfortable with that answer, stick to products which are marked "Pasteurized". In particular, as we have toured the plant, Martinelli's Juice is tunnel pasteurized after filling.

If the juice is in a carton, it was likely filled aseptically (in a sterile clean environment) and the risk is relatively low that that the package was allowed to pick-up any contaminants. For other topics related to pasteurization and pregnancy, there is a link to a resource center on the FDA website below.

Link To FDA Website

Pasteurizer Energy Consumption - Direct Steam Injection Machinery and Condensate Recovery

Friday, July 3, 2009

It is often said "there is no faster way to heat water than direct steam injection". That may be true, but there is also no more expensive method from an operating costs. From an ongoing expense standpoint, any system that allows for the re-collection of condensate and its return to the boiler will save money.

Direct steam injection pasteurizers and warmers can generally be converted at a reasonable energy payback to return condensate to the boiler. What's so big about condensate?
  1. It's new water and effluent cost that can be avoided
  2. It's already been treated with boiler chemicals
  3. (Most importantly) it has heat.
The condensate brings hot water back to the boiler which does not need the heat or chemicals which new water coming into the boiler would need. Click here for a great article on estimating the $$ associated with returning condensate.

Existing direct steam pasteurizers and warmers can generally be converted to coils, or a single heat exchanger to Hot Water with a fantastic energy savings.