Updated to add a Staling Rate Reduction for additional flexibility with light or dark roasts.



Enjoy

Hi Ian,

Thanks for your continued contributions.

I remain somewhat skeptical regarding the degree to which coffee staling in the freezer can be modeled with this or any other mathematical formula, regardless of how many variables are seemingly incorporated into it.

I find that for myself and my own usage, assuming immediate freezing after roasting, that the major determinant of what I get after defrosting is the quality of what I put into the freezer in the first place! This is, of course, the old "garbage in, garbage out, theory"

Assuming cold storage, for the purpose of this post let's say ~0 degrees F, and freezing soon after roasting (I like to freeze within an hour, however some will freeze a couple of days later), I'd bet that as long as one freezes in batches that can be consumed within ~3 days, that it is very unlikely that these frozen coffee samples will be "staled" unless they have been frozen for a period exceeding 3-4 months (and even then, I lack data to say that, for example, 5 months is unacceptable).

Almost anything can be reduced to a mathematical equation. What we need to watch out for is an equation that seems to answer most every conceivable question, but that has not really considered what we do not know as much as it has considered what we think we might know, and in the end doesn't answer the questions it purports to to incorporate.

ken

Hi Ken,

I've been more or less following the freezer aging curve for a couple of years and found it to be quite reliable for the style of coffees I drink. The 2.0 curve may not work for all coffees. I'm hoping that the tool gets some use and we get some quantifiable feedback. Hence, the adjustable staling rate.

For my 2p, professional roast coffee that I enjoy on days 4-6 frozen a day or two post roast in a -20°C frost free in 120g put-ups follows the 2.0 staling curve nicely. Up until about a month post freeze, the coffees need a day or two rest. For the second month, the coffee can be removed the night before and used immediately. I don't purchase more than I can use within about two months. The one time I did purchase a 3+ months supply, the end of the 3rd month was a chore. For coffees that fare better on days 10-12, a quick glance at the calendar and a printout of the table tells me how much in advance I need to remove the coffee from the freezer.

We were out of the country this past weekend for 5 days. Coffee roasted May 19, frozen May 21 and removed from the freezer Jun 23 [calculated age about 4 days] was left out in its sealed jar. A new packet was removed Sunday evening. Monday morning, the newly removed coffee smelled wonderful and pulled great shots. The aroma of the stuff that sat out for 5 days was clearly past prime and it decorated the front of the machine, the drip tray and put as much coffee on, as in, the cup. The shots were thin and eminently sinkable.

cafeIKE wrote:We were out of the country this past weekend for 5 days. Coffee roasted May 19, frozen May 21 and removed from the freezer Jun 23 [calculated age about 4 days] was left out in its sealed jar. A new packet was removed Sunday evening. Monday morning, the newly removed coffee smelled wonderful and pulled great shots. The aroma of the stuff that sat out for 5 days was clearly past prime and it decorated the front of the machine, the drip tray and put as much coffee on, as in, the cup. The shots were thin and eminently sinkable.

Quite the opposite of what I'm getting for results aging first & then freezing. Considering that you are storing your roasted coffee in a storage freezer at -20F & I'm storing mine in a Frost Free storage freezer at -5*F I'm surprised at the rapid aging you are seeing. Are you vac bagging your roasted coffee that goes in the freezer?

Today I'm pulling shots of Redbird espresso that was roasted on 5/5/10. This was a 5lb bag I let rest until 5/11/10, vac bagged in 1/4lb portions & froze. I removed the portion I'm using today from the freezer yesterday so 7 days total rest out of freezer, 1 day shy of 5 weeks frozen. The shots I'm getting today are the same sweet, creamy, nutty/chocolate shots I would get if I were pulling shots 7 days post roast. Nice pours, lots of crema, ect. Based on recent experience this will continue for the next 2 days while I use up this portion. This is typical of what I've seen when resting first, then freezing Dolce or other commercially roasted blends.

JohnB. wrote:Considering that you are storing your roasted coffee in a storage freezer at -20F & I'm storing mine in a Frost Free storage freezer at -5*F I'm surprised at the rapid aging you are seeing.

Cannonfodder has a -20°F storage freezer.

My refrigerator frost free freezer compartment is about -4°F / -20°C with forays to about -10°C to defrost. Coffee frozen soon after roast is good for at least 8-10 weeks. I'm confused how this is rapid staling

Sorry, mixed up the -20*C & -20*F. I'd consider the results you described, which I quoted in my post, to be an example of rapid staling while frozen. You froze the beans 2 days post roast & removed them from the freezer 4 weeks later. They rest on your counter for 5 days, a total of only 7 days rest (out of the freezer) & your beans are stale/unusable?? Typically it would take any of the commercially roasted blends I've used 12-14 days (total out of freezer time) or more to reach the state you describe. Now that you've pointed out that you are using your FF fridge freezer for long term storage it's understandable.

I use a deep freezer which is much colder than your typical chill chest freezer. Long term cold storage is a must with a big garden and a bunch of assorted woodland critters that need to keep for months, not to mention the occasional body. Don't tell the cops about that last part...

It also works wonderfully for storing your greens if you home roast. I recently found some vac packed greens in the bottom of the freezer while reorganizing things. If I remember correctly, they were around two years old. Roasted them up and tasted as good as I remember the coffee being when it was fresh off the delivery truck.