I also started freezing coffee since the freezing article - though like nicolas I only got a compartment in the normal fridge that is approx at -15 deg C. I also got the impression of an increased aging after the beans have been frozen (even with letting the beans come to room temp before opening the bag) but that doesn't bother me because I'm making badge size just enough to be used up within 2 days. I'm freezing them just when the 'optimum window' starts to open (usually around day 5 post roast).

I've been freezing, too, and my sense is that it causes the beans to age more rapidly than coffee that hasn't been frozen. It's usually not a problem because I don't defrost more than 3-4 days worth of beans at a time. But I had one instance where I defrosted two jars of two different coffees and therefore used each of them more slowly. I detected a distinct sour smell in both jars after a week or so. That hasn't happened with coffees I've defrosted and consumed within 3-4 days.

I've been freezing immediately after receipt from the roaster, which is usually 1-3 days after roasting. I haven't had crema problems related to the beans being too fresh. But it sounds like I should let the beans that arrive within 1 day rest longer before freezing, and perhaps let certain blends rest even longer.

I have the following on the way:

Intelligensia Black Cat
Stumptown Hairbender
Terroir Ethiopian Ademe Bedane
Terroir Daterra

Can anyone give me guidelines for how long to let each of these rest in the bag after roasting and before freezing?

timo888 wrote:I don't know about the beans developing brittleness, and fracturing when ground. They're oily. And mine are not being kept in the deep freeze in the basement but in the refrigerator's freezer compartment. They're there only for two-three weeks as a general rule, though sometimes longer.

But maybe it's time for some electron microscopy.

The electron microscope is a wonderful tool but not for this purpose in my opinion. Sample preparation for analysis by EM requires drying the sample and keeping under a very tight vacuum. That would I believe not represent coffee grinds as we use them. Rather I think a good dissecting microscope and camera with size standards as controls would more accurately reflect ground coffee at room temperature and humidity. The study by John Weiss using a laser defractometer

Titan Grinder Project: Particle size distributions of ground coffee

was I believe a very nice study using a technique that works well for this purpose.

I don't have anything to add on the subject of grinding frozen beans or of condensation that might occur from repeatedly opening and closing a container that spends most of its life in the freezer. For one thing, I have no personal experience with this approach, and for another I don't want to simply repeat old hearsay that was one of things that motivated us to study the effects of freezing in the first place.

Personally speaking, the above approach was not what I was suggesting, as I do think that coffee evolves in interesting ways during the time when it is at its peak. If the given coffee is at its peak on days 4, 5, 6 and 7, I think that all of these days are interesting and none of them is necessarily "better" than any of the others, just that those days (4,5,6,7) are demonstrably better than days 1-3, and the days from day 8 onwards. I have had an occasional coffee that really seemed to come into its own after 10 days, but those have been very rare, and of course, there is nothing to stop you from getting to know your coffees and tailoring this approach to each one individually.

malachi wrote:so... not "better" in the sense that freezing inherently improves espresso, but "better" in the sense that you don't have to consume espresso made from "past their prime" beans? (just want to be clear on this)

Absolutely. I don't believe that freezing changes coffee in a positive way, rather I believe that it retards staling and that it does not cause any obvious damage. As such, given the relatively short peak usage period of any given coffee, one could consume more of the coffee when it is at its prime by using the freezer as a temporary "time shifter."

As to the posited effect of freezing upon the later aging of coffee once defrosted, I haven't noticed any impact of freezing, although I don't think that coffee absolutely stops degassing while in the freezer, rather that it has merely had its rate of degassing very much reduced. As such, I tend to allow the coffee removed from the freezer to degass for less time than I would were the coffee right out of the roaster and never frozen (I might use it on day 2 out of the freezer rather than on day 3 or 4 for fresh, never frozen coffee). Some of my observations have to do with the fact that I do not allow the coffee to degass much before I freeze it; generally, my coffee is in the deep freeze within an hour or less of when it gets dumped into the cooling tray. If you don't roast yourself, this is simply not an option. All other things being equal, however, I see no benefit whatsoever of degassing coffee for an instant longer than necessary after you take possession of it; you can always degass it more later, and you can never turn back the clock.

In summary, I do like how coffees evolve during their peak periods and I do want to experience that. For me, that argues against trying to "freeze the moment" after degassing in the hopes of drinking all of a batch of coffee when it is at one point during the "prime period," but rather simply to try to consume as much as possible of a given batch of coffee during this multi-day period when the given coffee shows at its best.

ken

Just for another point of view...I NEVER freeze coffee. For several years now I have gotten my beans the day they are roasted, let them rest for another day or so and then and I consume them within ~ 1 week.

I can see why one would freeze if they were buying commercially roasted beans mail order as shipping is much less per pound for 2 pounds than for one - or if one were roasting in big batches (but why roast in a big batch?). Why are you guys freezing so much?

Len

Worldman wrote:I can see why one would freeze if they were buying commercially roasted beans mail order as shipping is much less per pound for 2 pounds than for one - or if one were roasting in big batches (but why roast in a big batch?). Why are you guys freezing so much?

Your numbers are a little off--2 lbs. I think most of us could use within the reasonable window. I buy 4-5 lbs of beans from Intelligentsia (or whomever)... now shipping is REAL cheap per pound--much more reasonable pricing, and easier to justify buying from roasters of that caliber more often.

Worldman wrote:Just for another point of view...I NEVER freeze coffee. For several years now I have gotten my beans the day they are roasted, let them rest for another day or so and then and I consume them within ~ 1 week.

I can see why one would freeze if they were buying commercially roasted beans mail order as shipping is much less per pound for 2 pounds than for one - or if one were roasting in big batches (but why roast in a big batch?). Why are you guys freezing so much?

Len

As Nicholas indicated, the desire to reduce per pound shipping costs is what drives many here to freeze commercially roasted coffee.

From the standpoint of home roasters, batch sizes and/or roast session sizes will be determined by the individual's schedule and also their equipment. My 1lb sample roaster produces approximately 380g of roasted coffee every 17.5 minutes or so, which adds up to almost 3lbs of roasted coffee per hour. That roast batch time exceeds the time of the roast itself, but is necessary because I must allow the drum to cool down to around 350F before I introduce the next batch of green beans, or the beans risk being scorched. Before I can roast my first batch, the roaster has to preheat for around 15-20 minutes, and in order to reduce the risk of drum damage, the roaster must continue to turn without the heat on for 20 minutes at the end of each roast session. Clean up of chaff in the garage and of the roaster itself and time needed for bagging/packaging adds to the overall time.

There are others who use bbq roaster drums, and batch sizes for those drums are also going to be larger than what your typical home roasting device produces.

I roast not only for myself but also for a couple who are longtime friends.

As you can see, my roaster does not become time-efficient unless a roast session includes multiple pounds, so the short answer to your question is that I don't like to waste my time and prefer to increase my efficiency by roasting more than a pound or two in each roast session.

Another reason for freezing would be if you like to switch coffees frequently. I have 4 grinders in my kitchen (which is really crazy) and I tend to use about 3 of them at any given time to have some variety. Freezing allows me to have that variety available even if my most recent roast session did not include so many different types of coffee. Someone ordering roasted coffee from different high end roasters might freeze for the same reason; to have more variety.

The longer answer to your question is that there is absolutely no proof whatsoever that freezing does anything other than reduce the rate of staling of coffee that would otherwise occur rapidly to roasted coffee stored at room temperature. There is, however, no shortage of mindless drivel that is expressed verbally and in written form on the internet saying or implying that freezing is detrimental to roasted coffee. Had the subject not been tested in a controlled fashion then it would be simply a matter of opinion, however it has been tested and retested in a "scientific fashion" with a number of different tasters and posted in detail for everyone to view here http://www.home-barista.com/store-coffee-in-freezer.html and here Freezing Espresso Coffee, Part Two This is not to say that the two referenced pieces are the final end statement on the subject, but it is to say that before one can imply that freezing is ill-advised, a little proof might be useful to support that unfounded position.

Finally, even if you are only buying 1-2lbs of coffee at a time, unless you have more than a couple espresso drinkers in your household, it is unlikely you can consume all of that coffee when it is at its absolute peak (maybe 4 days in duration), which was, the whole point of this particular thread in the first place.

ken

I most frequently get my coffee from Espresso Vivace Roasteria in Seattle. They use USPS Priority Mail to ship my coffee; it's roasted Monday, delivered to me in Berkeley on Wednesday.

If one orders one pound of coffee, the package itself weighs more than one pound, as you have the weight of the cardboard box, the single sheet of paper upon which the invoice is printed, the tape used to seal the package -- trivial, perhaps, but remember that you're not paying the one pound rate. Let's add four ounces to account for that "extra."

If you go to the USPS Postage Rate Calculator, select "Package" and "1 pound, 4 ounces" and "Priority Mail" (not "Flat Rate Box") you'll see that the online price is $6.67 postage for a domestic shipment, or $7.10 if you pay for postage at the post office. At 2 pounds 4 ounces, the rate is $8.15 online/$9.05 at the post office -- making the per pound rate $4.08/$4.53, respectively for two pounds of coffee. At 3 pounds, 4 ounces, the rates are $9.78/$10.80 -- or $3.26/$3.60 per pound, roughly half the rate when shipping a single pound. At 5 pounds, 6 ounces, it's $13.34/$14.65, or $2.67/$2.93 per pound.

Since Vivace packages their beans in half-pound bags, it's easy to pull out one bag at a time, and use it up in 3-4 days . . .

Cheers,
Jason

Jason's illustration is a pretty apt one. I would add: roasters don't always offer USPS--and they also don't always charge the exact rate that USPS charges you for shipping, since they are charging shipping and handling. Most roasters offer high-volume discounts of some kind. I can think of at least 2 roasters off the top of my head (Cuvée and Coffee Klatch) that give you a 20% discount for buying 5 lbs. bags over smaller ones, in addition to the savings on the flat shipping cost of the order. Paradise Roasters' pricing structure gets you free shipping on orders over $25 AND and additional 10% off your order if you buy 6 12 oz. bags (4.5 lbs.) of a single coffee.

There are lots of different pricing stuctures out there from online roasters, and all of them save you money for buying larger volumes of coffee. Sometimes the savings are disappointing or uninteresting; sometimes it's pretty surprisingly huge. The fact remains that if you consume a pound a week or more and buy from specialty roasters on the internet, the price difference between ordering once a week and ordering once every 3-5 weeks will be in the hundreds of dollars per year. You could get the extra money you spent on a Compak K10 or Mahlkönig K30 in shipping savings, without sacrificing coffee quality (assuming you follow Ken's methodology, and possibly even if you don't), in a matter of 3-4 years.

Ken Fox wrote:As to the posited effect of freezing upon the later aging of coffee once defrosted, I haven't noticed any impact of freezing, although I don't think that coffee absolutely stops degassing while in the freezer, rather that it has merely had its rate of degassing very much reduced. As such, I tend to allow the coffee removed from the freezer to degass for less time than I would were the coffee right out of the roaster and never frozen (I might use it on day 2 out of the freezer rather than on day 3 or 4 for fresh, never frozen coffee). Some of my observations have to do with the fact that I do not allow the coffee to degass much before I freeze it; generally, my coffee is in the deep freeze within an hour or less of when it gets dumped into the cooling tray. If you don't roast yourself, this is simply not an option. All other things being equal, however, I see no benefit whatsoever of degassing coffee for an instant longer than necessary after you take possession of it; you can always degass it more later, and you can never turn back the clock.

In summary, I do like how coffees evolve during their peak periods and I do want to experience that. For me, that argues against trying to "freeze the moment" after degassing in the hopes of drinking all of a batch of coffee when it is at one point during the "prime period," but rather simply to try to consume as much as possible of a given batch of coffee during this multi-day period when the given coffee shows at its best.
ken

If I wanted to do that I could just roast a batch & leave it out of the freezer, using it until its gone. I freeze in small lots so that I have a variety of roasted coffee ready to use when I want it with no waiting or planning ahead. I open the freezer in the morning & pick out something interesting for the vac pot or espresso or both. Toss the bag on the counter or up on the cup warmer & in a few minutes I'm ready to brew or pull shots. If I want something different later in the day out comes another bag ready for use as soon as it warms up.

As to the beans degassing while in the freezer I have left beans in there for 6-8 weeks or longer & the vac bag was just as tight as the day it went in so any degassing would have to be extremely minimal. Once the beans warm up on the counter the bag will start to expand indicating that the beans are once again degassing.