What cold-pressed, pasteurised and HPP juice mean

Cold-pressed, pasteurised and HPP describe three different things. Cold-pressed says how the juice was squeezed out of the fruit. Pasteurisation and HPP (high pressure processing) say how the juice was treated afterwards to reduce harmful germs. One bottle can be cold-pressed and also treated by either method. On a Thai label, the wording the law sets is about how much fruit the drink contains, not about the method.

What each word describes

Cold-pressed is about the pressing step. A Rutgers University fact sheet describes it as placing ground fruit and vegetables in a permeable pouch and applying a large amount of pressure until the juice is freed from the pulp. The word says nothing about what happens to the juice after pressing. In the Thai notification on drinks in sealed containers, the term does not appear, so it is a description used by makers, not a defined label name.

Pasteurisation is a heat treatment. The US Food and Drug Administration (FDA) describes it as a heat treatment strong enough to destroy the active, growing cells of disease-causing germs.

High pressure processing (HPP) treats juice without heating it. The sealed pack is placed under very high pressure for a short time. Research papers describe it for juice at pressures of 400 to 600 MPa for 1 to 15 minutes. MPa stands for megapascal, a unit of pressure.

What the safety rules ask for

The rules below belong to two different countries, so they are kept apart.

In the United States, most juice makers must treat juice so that the most resistant harmful germ of concern falls by at least "5-log". The FDA explains this as a 100,000-fold reduction. The rule does not name one method. Heat is one way, ultraviolet light is another, and research papers describe HPP as a non-heat way to reach the same goal. In general, a juice that has not been treated in this way must carry a warning on the pack saying that it has not been pasteurised and may contain harmful bacteria.

In Thailand, the Ministry of Public Health notification on drinks in sealed containers sets limits for ready-to-drink products. Coliform bacteria must be below 2.2 per 100 millilitres, and E. coli must not be found. Yeast and mould must be below 1 per millilitre for drinks treated by sterilising or UHT (ultra-high temperature, a strong heat treatment), and below 100 per millilitre for drinks treated by any other method. The notification does not use the words pasteurised, cold-pressed or HPP. For yeast and mould it sorts drinks only into two groups, sterilised or UHT and everything else.

Storing treated juice

Follow the storage instruction printed on the pack. The treatment matters for how long juice lasts. In one laboratory study of rice grass juice treated by HPP and kept at 4 degrees C, yeast, mould and total bacteria were not detected over 12 weeks, while untreated juice showed microbial growth within the first week. That is one study on one kind of juice, so it is not a promise for any particular bottle.

What "100%" means on a Thai label

The same notification sets the names a fruit drink may use. The wording depends on how much fruit it contains:

"น้ำ (fruit) 100%" is for a drink made from fruit alone.
"น้ำ (fruit) 100% จากน้ำ (fruit) เข้มข้น" is for a drink made by adding water back to concentrated fruit juice, so that it matches the 100% drink. The word for concentrate must appear in the name.
"น้ำ (fruit) (number)%" is for a drink with at least 20% fruit by weight that does not qualify for the 100% names. The percentage must be stated.
"น้ำรส (fruit) (number)%" is for a drink with less than 20% fruit by weight.
"น้ำหวานกลิ่น (fruit)" is for a sweet drink that gets its fruit flavour from synthetic flavouring.

So the number in the name is the fruit content set by the notification. A drink named "น้ำรส" with a figure under 20% is a flavoured drink, not a fruit juice in the 100% sense.

In short

Cold-pressed describes how juice is squeezed out, not how it is treated afterwards.
Pasteurisation uses heat. HPP uses very high pressure without heating. Both aim to reduce harmful germs.
Thai rules set microbial limits for sealed drinks and name fruit drinks by fruit content, not by pressing or treatment method.
In the United States, juice that has not been treated to the 5-log standard must carry a warning label.
Storage instructions on the pack are the best guide to how a particular juice is meant to be kept.