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Nitrogen Flushing

PostPosted: Fri Jan 30, 2009 4:41 pm
by Jim Dikaios
Wondering about the importance of nitrogen flushing. We presently package whole beans in one way valve bags right after roasting, but we do not nitrogen flush. Any insight on the pros and cons would be greatly appreciated. Any equipment suggestions for low volume 5lb packaging.

Thanks, Jim

Re: Nitrogen Flushing

PostPosted: Sat Jan 31, 2009 11:05 pm
by Mark Inman
Jim, I am going to go out on a limb here and say that if you able to package your coffee into a valve package quickly from the roaster (under 1 hour), then nitrogen flushing is not necessary.

With my experience with both bagging and canning coffee, when I package my coffee within an hour of roasting, the massive release of C02 from degassing forces out all the ambient oxygen, leaving a stable environment for adequate preservation. Numerous 02 testing confirms this theory.

If you have the type of production line that does not allow for immediate packaging, Nitrogen flushing makes a lot of sense.

It is, though important to note that if you are going for 100% organic ingredient certification, nitrogen flushing is not allowed. It is considered a prohibitive additive.

I hope this helps.

Mark Inman

Re: Nitrogen Flushing

PostPosted: Sun Feb 22, 2009 10:01 pm
by Poul Mark
What are the test results in terms of lab results?

We have found that Nitro flushing does in fact prolong and stabilize coffee. In simple taste tests, comparing nitro flushed coffee, to non-nitro (valve bag) coffee the results are significantly different. When we shipped our nitro flushed bag for testing the residual O2 levels were less than 1.5%. While we did not ship comparative bags of non-flushed bags for testing, the proof was in the pudding, or in the cup. After 24 days, the espresso was awesome when pulled from the nitro flushed bag, but flat and baggy when pulled from an ordinary, one-way valve bag. So in short, our testing has shown that nitro flushing does preserve freshness and offer stabilization, at least in talking about espresso. Further, we have tested this on Esmeralda, and found the same results.

Re: Nitrogen Flushing

PostPosted: Mon Feb 23, 2009 7:08 pm
by Jim Dikaios
Thanks Mark and Poul.

Any suggestions for 1-5lb bag sealers with nitro flushing capabilities that won't break the bank?


Re: Nitrogen Flushing

PostPosted: Thu May 07, 2009 4:21 am
by Jack Hanna
the expulsion of CO2 after roast does not replace the oxygen levels 100%, there are still large amounts of oxygen left in the bag after straight packing.
More than 10% in fact, from oxygen metres.
benefit is definitely with flushing.

Re: Nitrogen Flushing

PostPosted: Thu May 07, 2009 6:02 am
by Shawn H
The way you set the test up has a significant effect on the result. If you package the coffee quickly (within an hour as Mark stated) and have little to no head space in the package you can achieve low (less than 2%) 02 levels with 24 hrs. The longer the time between packaging and the amount of head space will both significantly increase the O2 levels in the package.
The safest way is to flush with nitrogen, hen you don't have to worry about it, but it can be done.

Re: Nitrogen Flushing

PostPosted: Thu May 07, 2009 5:08 pm
by Phil Robertson
I wonder if the benefit of nitro-flushed is most realized when coffee is shipped. We brought a number of coffees back from Europe recently (Tim Wendelboe, Koppi, Square Mile, Coffee Collective). All these espressos tasted wonderful when we where there, but only the Coffee Collective spro survived the voyage (it was the only coffee that was nitro-flushed, I believe).

One a side note:
Does anyone know why nitrogen is the defacto gas used to flush the atmosphere from roasted coffee bags? The wine industry seems really hot on argon over nitrogen, as does the food industry.

Re: Nitrogen Flushing

PostPosted: Thu May 07, 2009 9:32 pm
by Jack Hanna
Yes of course and agree
however that is quite unrealistic if you happen to have a multi-blend roast.
When you post roast blend, often the other origins \ estates sit whilist waiting for the rest of the origins to finish.
its also very hard to do if you have a large production value.

the < 2% oxygen often still affects the blend post 1 week...
where as flushing expells the oxygen to almost 99.8% oxygen free..
in the test that we've had, same coffee packed w\ and very quickly after roast without nitrogen
tastes completely different after 2 weeks
one is a lot more volatile than the other.

Re: Nitrogen Flushing

PostPosted: Sat May 09, 2009 6:05 am
by Klaus
Glad to hear the coffee survived the trip. I don't know if any of the others nitrogen-flush but we do. The exact reason for nitrogen over other gasses I'm not sure of, but I've heard two in the past: 1) that nitrogen doesn't react with the coffee and 2) that nitrogen already makes up 78% of our atmosphere. I know nitrogen is used in a lots of other food packaging too.

Re: Nitrogen Flushing

PostPosted: Sat May 09, 2009 7:55 pm
by Jack Hanna
@Klaus @Phil

Nitrogen is used in the food industry because of its ability to reduce rancidity and redox.

nitrogen as a pure element has no smell, no taste and no colour, which means the chances of it affecting the taste and smell of coffee or foods are next to zero.
as you also said there is an abundant amount of nitrogen in our atmosphere and it is relatively inexpensive to produce than other noble gases such as Argon (which is also used to displace oxygen in other industries).
Because Argon is created from liquid nitrogen and liquid oxygen, it is therefore a lot harder to produce on a smaller scale.

The primary reasons for using Nitrogen is the fact that its molecules have a larger diameter than oxygen. So when used with a slow release valve, the nitrogen molecules essentially squeezes the oxygen molecules out before its own escape.
Nitrogen also has a very strong bond structurally so therefor its very non reactive, thus stable enough to not produce other unwanted reactions.