Hi,
Due to my job, I will only be able to make espresso on the weekends this summer. So what should I do to keep my beans fresh as long as possible? I see two possibilities:

1. Divide fresh beans into portions for each weekend (something like 4 doses worth) and freeze these portions in jars or bags. Then I'd just take one of these jars/bags out of the freezer each weekend.

2. Freeze all fresh beans in one bag/jar and just take out a dose each time I need one. I'd try not to let the bag/jar thaw each time, but I'm worried that the beans wouldn't last as long this way.

Any suggestions? Does anyone else deal with this problem?

I had this problem last summer, and I solved it by making Chemex drip and/or AeroPress during the week. AeroPress and a hand grinder fit perfectly in the bottom drawer of a cubicle (if that's the kind of job you have) and don't make much noise. And grinding fresh coffee makes an office smell GREAT.

If that's not an option, mason jars might be a good idea. I think multiple, small jars have been the general suggestion around here (from what I remember) - you might not want to open a jar in the freezer, pull some beans, and put it back. It seems "cleaner" to take out a whole jar from the freezer each time you need one and leave the rest untouched (apparently any condensation on the beans when the larger jar is opened to room temperature air can cause some trouble).

Good luck and sorry about the lack of espresso during the week.

You could just reseal the bag at the end of every weekend and refreeze. That way the coffee ages two days per week. However, I'm not sure whether refreezing is harmless. With no free water in the beans that can crystallize or dry out, the major reason never to refreeze doesn't apply.

If you can, it's an opportunity to experiment by comparing a coffee aged regularly for a week to one refrozen several times.

frankmoss wrote:Hi,
Due to my job, I will only be able to make espresso on the weekends this summer.

I know this is kinda contrary advice, yet given out of pure heart: try to get a small open boiler lever machine and a hand grinder for work setup. It will payoff not only in availability of espresso at work!

Thanks for the quick responses. I'm going to be working in a research lab in a different city, and I'll only be home on the weekends. Lugging my 75 lb Faema Compact around isn't really an option. I'll probably just make drip coffee during the week. Being a college student, buying another machine is not really in the budget.

But in any case, I have a pound and a half of fresh Vivace Dolce, and I like the idea of an experiment. I'm a chemistry major, so it's right down my alley. I know that some molecules don't tolerate several freeze/thaw cycles (such as the proteins that I use at work). I don't know if any of the compounds in coffee beans are sensitive to freezing and thawing though. The aqueous solution that the proteins are in may be the cause of their instability when freezing and thawing. I think I'll design an experiment that's something like this:
Control 1-80 g of coffee
Control 2-80 g of coffee
Experimental-400 g of coffee
I'll keep Control 1 in the freezer for 4 weeks, so that it doesn't age any. I'll keep Control 2 in the freezer for 3 weeks, and leave it out for a week after the third week. That way it will age for one week. I'll take the experimental jar out for two days each weekend and use coffee out of it. After it has spent a total of 7 days out of the freezer (fourth weekend), I'll take Control 1, and compare the three coffees. I'll be comparing 7 days of aging at room temperature to seven days worth of aging with 4 freeze/thaw cycles. I'll also be able to compare both of these to coffee that hasn't aged.

Sound like a good setup?

I think you need a Mypressi TWIST!

frankmoss wrote:Sound like a good setup?

Very good indeed, nice design!

If you can, do some side by side brewing as well as espresso shots. I know that's not the point of the exercise, but it's easier to taste differences in brewed coffee (especially if you let it cool to just above room temperature, about 10 to 15 minutes after brewing).

Another thing I would take advantage of if I wasn't drinking much coffee (after the experiment is over) is Roaste.com as they sell some great coffees including from several HB sponsors with no shipping costs, so you could buy one pound at a time and still keep the per pound price the same or lower than it normally is when you buy many pounds from most vendors.

Even though I'm drinking plenty of coffee the last few weeks I've ordered much more often, but in much smaller quantities because of the lack of shipping charges.

Interesting test, I look forward to your observations. Personally, I divide up the coffee into pint jars and freeze it. Then I retrieve one jar, dump it in the grinder and go. I had not given refreezing proteans much thought but if use zip top valve bags, retrieve the bag, remove a couple days worth of coffee, zip it closed and return it to the freezer, I doubt the frozen coffee will have un-thawed during those few moments. Given the fact that coffee has somewhere around 700 chemical compounds in it last time I checked, it is hard telling what effect repeated freeze/thaw cycles would have on it.

As Jim points out, there is so little moisture in the coffee that crystallizing is not much of a concern. However, given your location and its tendency to high humidity, I would be worried more about condensation on the beans once you open the bag. The valve bag will start to frost almost immediately when removed from the freezer from the ambient humidity. Once you open the bag that humidity gets on the frozen beans as well. With enough open/close cycles, you could end up with frosted freezer burnt coffee just from the humidity.

Good point, Dave. Fortunately, my espresso equipment is in a humidity-controlled basement, so humidity is less of a concern than it normally would be. I'm getting excited about this experiment and am starting to wish that I had more coffee. I'll be sure to follow up when I have some results. I'll try some brewed coffee as long as I have enough left after the month.

Does anyone know if anyone has used an HPLC or other instrument to quantify the in-cup difference between coffee made from fresh beans and coffee made from stale beans? It would certainly be a big endeavor.