Maybe most of you will see a bag of coffee will have several holes on it, and you also can smell the

aroma from a bag of coffee.

Do you know why ?

--There is a piece of one way valve on the coffee bag.

Why the coffee bag have a piece of one way valve on it?

--After roasting, the coffee bean or coffee powder will release more and more CO2. A piece of one way

valve can release the CO2 outside the bag.

Is it necessary to have a piece of one way valve in the coffee bag ?

--We got many answers about this questions, Is it necessary to have a piece of one way valve in the

coffee bag? Below is some of answers from our professional partner and friends:

--1.Mr.Franck: “it's purely there so that the gases produced after the beans have been packed and

roasted, can be released and stop the bag from filling up with carbon dioxide and blow up.”

--2.Mr.ROBERT: “ Valves are necessary when Fresh Roasted Coffee is packed in High Barrier bags.

Without the valves, gasses build up and will cause the bags to burst. If coffee is left out to off-gas first, the

coffee loses flavor as well. The valves let gasses out but no oxygen in. This preserves the flavors for a

longer time. The Paper bags are Low Barrier and the gasses escape without the valve but the oxygen

can also come in. It is all based on the shelf -life required. Two or three weeks = Low barrier, several

months = Higher Barrier, 1 year = Very High Barrier.”

--3. MR. Mark: “These are one way valves that allow gasses to escape but doesn't allow gasses

(specifically oxygen) back in.”

--4. Mr. Matthew: “They would balloon or burst if not!”

Now Color Suns offer you our own idea of why it is necessary to have a piece of one way valve in the

coffee bag?

--1. The green coffee will be roasted by the roaster. And then the coffee bean after roasted, they will

release more and more CO2, some of roaster will put the coffee bean in a few days to release the co2.

And then they will put the coffee bean or coffee powder into the coffee bag. But the coffee bean still will

release a little co2 while they put them into the coffee bag in a few days after roasting. At this time, the

one way coffee valve can help you release the CO2 outside the coffee bag. (That is also why you can

smell the coffee aroma from the coffee bag.)

--2. The co2 in the coffee bag which can make the two bad effect: 1.The co2 will oxidate the coffee bean

or coffee powder while they in the bag, that will effect the fresh of the coffee while we taste them. 2. Too

much co2 in the coffee bag will make the coffee bag explode, that whole bag of coffee will be waste, this

is a big lose.

Why the coffee valve also called “one way valve” ?

--The one way valve can release the co2 at the mean time, it can prevent the outside air getting into the

bag through the one way valve. That is why we called the coffee valve “one way valve”. The outside air

get into the bag also will make the coffee oxidation, it will effect the fresh of the coffee.

How to come true the releasing by the one way coffee valve ?

--Firstly, you must have a piece of one way valve.

--Secondly, you must have one unit of valve applicator machine.

--Thirdly, you must have a piece of coffee bag.

--The valve applicator machine can help you install the one way valve into the coffee bag, it is very easy

to control and install the valve into the bag.