Similarities between rice and coffee storage

Rice is about as commodity as it gets. Well, I like to think that but then I have been noticing that even with something like rice, care given to packaging is moving well ahead of what we deal with in green coffee.

A trip to the local mega asian grocer (Kan Man in Quincy) led me to make note of a few interesting things with one strong observation, the packaging is getting serious.

At our local Korean grocer in Union Sq. Somerville, there is an assortment of rice available in many grades. What's interesting about it was how they noted crop year and an emphasis on packing as each bag had it's own 'patent pending' method of storage. Most of which seemed to be nitrogen flushed or tightly vacuum sealed which I must say does seem to make a difference.

In wandering around Kan Man viewing the stacks of vacuum sealed rice varieties stacked on the shelf, that I had a good chuckle. So much obsession over rice, a product I have been used to seeing in bags akin to dog food packaging. Then it hit me how young our coffee industry is and how absurdly ironic it was.

The fact that preservation packaging is still such a novel and absurd idea really instills a sense of how far coffee still has to go and just how far behind it is. The truth is that there is so much information out there to digest and yet not nearly enough quality data therein. Like most things coffee, too many opinions and not enough data or research being done.

Without vacuum packaging, our business would not be enjoying it's first year in celebration. Putting it in perspective, packaging for preservation makes a difference and we have the experiences under our belt to prove it. If other people don't agree with us, that's fine because everyone needs to learn their own lessons but we know what works and will keep working with it.

As the weather turns, let's keep an eye on the temperature and think about the effort that goes at every stage into one taste of coffee down the line. There are so many things that can destroy a coffee from the time is is picked through processing, transport, the roast, and then with brewing at the barista level. It does not begin and end solely in the hands of a barista, it's a process that started months ago and continues even while sitting in a warehouse.

Packages matter

New delivery, originally uploaded by coffeedirtdog.

Storing roasted coffee

I get asked a lot about how to store coffees once roasted. Freezing, vac sealing, canning, you name it, I have heard it. So here is a bit of advice for those using fresh coffee:

Oxygen is your enemy. Do not use anything with head space for storage. Canning jars with the nifty valves do not work. Even small amounts of Oxygen expedite the coffee's volatiles toward flavor degradation. For oily darker roasts, it can even speed up the development of rancid flavors so think about keeping the air out.

Moisture is very bad. Freezing can be fine but if you don't protect the coffee from condensation adequately, moisture will contaminate it. Much like green coffee, humidity is always a contamination problem but it is the day to day variance in humidity that presents the biggest problem. Reseal if you can but think about a storage space with the idea of keeping moisture out.

Heat is not a good thing. I shouldn't even need to explain this one. Store your coffee in a cool dark place at a very controlled and consistent temperature, not your counter top by the kitchen window...

So there, it's really simple. If you are one of those low consumption coffee drinkers who needs time to work through a bag, get a vacuum sealer like a food saver canister or one of the hand pump vacuum canisters that's so popular right now. Either put your coffee in the fridge or a cool pantry/wine cellar and pay attention. It's not milk but treat it as such and you can be assured if it wasn't good on day 5, it wasn't something you did in storage.

The Green Storage Project...

Aaron, Eddie and I had a long set of email discussions leading to what we are calling the green coffee storage project. It is a collaboration among people we respect to effectively explore what happens to coffee in normal storage and estimate what options are available to a roaster on a budget to keep green at optimal quality until the next crop and possibly beyond.

The key is not to break new ground but to establish data and facts in a project that is repeatable for most any home user or small budget roaster. A lot of opinions have been offered and we felt it was time to do the research instead. This project is about exploration and transparency rather than obtaining proprietary knowledge.


Goal: To determine the necessity for better green transport and packaging standards. To evaluate and graph green age. To summarize the results and then conclude how to slow or prevent coffee flavor/aroma deterioration due to green age.

To determine measures to preserve new crop taste through the entire usage of a coffee.

Key materials:
-Green Coffee(Finca Vista Hermosa Michicoy)
-Vacuum packing and freezing materials available on a reasonable budget

Key Test Components:
Set 1: Coffee stored traditionally at a warehouse; shipped from Guatemala via standard means 2-3 months from harvest.
Set 2: Vacuum sealed coffees stored by the roaster; expedited from Guatemala weeks after harvest/milling.
Set 3: Vacuum sealed coffees frozen at 0-20C by the roaster; expedited from Guatemala weeks after harvest/milling.

The Setup:
Four groups will each have sets of samples provided to them.
At intervals over a two year period, the samples of regular green, vacuum sealed and frozen will be opened and roasted against each other. It will be up to each group to note or identify any changes or differences in each coffee that they observe and share these notes with the other groups.



It was necessary to find respectable roasters who could look at the project from a pure quality standpoint and lend valuable notes on perceivable changes(if any) that existed in each set.

We appreciate Steve and Miguel joining Aaron and our crew in this venture. I hope they gain from this setup or at least enjoy the green in the process. I appreciate Edwin being so open to the idea and for his willingness to evaluate anything in the name of research or education. The goal is not to validate but simply for better understanding of green storage and the only expectation I have is that we will all come away with something from this project.

The project begins in the next few months and we at Barismo will be documenting bits and pieces of our personal experience when it is relevant.

Green coffee ages but what does that mean?

Stale: Having lost freshness, effervescence, or palatability.

Is it that simple for your green coffee? Is it possible that over time, something changes, and your coffee can lose it's flavor even before it is roasted?

The answer is surprisingly complex. In fact, to what level could depend completely on the coffee itself and the original flavors present. There is most definitely no catch all answer. Some coffees may show this "agey" flavor change whereas others may not show perceivable age. The important part in analyzing this is roasting in a way that you can perceive a difference. The one thing that is certain is that 'something' is changing whether we can perceive it or not.

Chemical and structural changes happen over time in storage that have been well documented. Temperature, humidity, and light seem be the things that can expedite those changes. It should be a given that exposure to chemical agents, molds, and other contaminants should be avoided but these can also contribute to biodegradability.

George Howell has pointed to lignins previously as proof of the biodegradability of coffee seeds. Lignin is a biodegradable plant material that is hydrophobic. This means it is water resistant and resists pathogens entering or possibly flavors escaping while acting like a glue binding the seed together. Coffee seeds are very waxy, so it really brings up the question of how hydroscopic the coffee is in the green state and what part that plays into the flavor changes. Lignins are only about 2% of the total coffee mass so it remains to be seen if this 'glue' is the sole culprit in bean decomposition or plays a part along with volatile flavor components that may escape over time.

What is truly curious is the relationship between sugars and how flavors form as well as the overwhelming topic of moisture content. Sugars are increasingly interesting according to the research on low molecular weight sugars in green and roasted coffee collected in Ivon Flament's 'Coffee Flavor Chemistry.' Poor storage was believed to result in an increase of glucose which correlated with a marked increase in woody/rubbery notes in the coffee. There was also an increase in water content during the same period, so it remains that moisture content of the bean is an easier measure of green quality than a quantitative sugar analysis. Storage in tropical temperatures (such as at origin) can even induce chemical changes such as the Maillard reaction in the green coffee.

So what does that tell you food scientists?
There are changes in coffee in the time it is stored that need to be addressed by expedited shipping, better storage method, and possibly freezing green.

Is that conclusive proof that we should all start flying coffee from origin and freezing green? No. What it points to is that we need to set up conditions where we can do a qualitative analysis of the changes coffees in storage go through and continue pursuing the upgrades you see from pioneers like Daterra Farm in bagging.

From a recent experiment we did with a CoE quality green stored in air conditioned storage and one frozen over the last year, we had a very stark contrast in the two. The differences we have noted are that floral citrus notes in wp centrals, wp Yirgs, and clean Kenyas appear to disappear over time to be replaced with a woodsy dull lifeless note and an unpleasant wheat or barley flavor. Aromatics disappear first, followed by changes in the citrus notes. Naturals turn quickly from the soft over ripe fruit into very muddy rotten fruit flavors over time in storage. We don't have enough notes on controlled dry process to state definitively what is changing.

Those are just our evaluations and this is a challenge to roasters to make their own evaluations and share their observations. Keep in mind that if the green quality isn't already very high, you may not notice the changes. This is not something to invest in your Sumatra at $1/lb but might make sense for that $20/lb CoE Guatemala.

Point being, if you paid a lot for this coffee, you should research keeping it in it's best shape as long as possible whether you are a professional roaster or the home variety.