[creative nickname] wrote: Conceivably grinding frozen beans could be valuable for darker roasts, when you wish to get a slower flowing shot while keeping things coarser to get a ristretto shot that isn't overextracted. The coldness of the grinds themselves would also help achieve a similar effect

interesting, I never considered this. I tend to make ristrettos frequently and always freeze my beans. I wonder if the reason for my preferred brew ratio is my use of frozen beans. I don't use dark roasts tho: darkest brands I use are ACME, Verve espresso blends.

So, I vacuum seal & freeze my 5 lb bag and pull out a jar when the hopper gets low. Occasionally I have found the hopper empty and have had to grind frozen beans. The last two times have produced God shots I can't repeat with the same beans the next day that have fully acclimatized. Is this the missing link?

jpender wrote:You'd think so but this hasn't been the case in my experience.

I took the trouble of measuring how much moisture was absorbed by beans that had been repeatedly removed and returned to the freezer. It was negligable, at least in the environment where I brew. And I could detect no discernible difference in taste (blind) between those beans and others that had remained sealed in the freezer.

I wonder if it's an issue of humidity? A couple times I've pulled a sealed bag right from the freezer, but only used up some of it. Within a day or two the coffee tasted noticeably "off." Enough so, that I've never taken another chance with it.

That is a good question. Are you putting the coffee right back in the freezer or taking it out and leaving it out? I haven't heard of anyone using humidity control with coffee storage at home, anyone try a Boveda 32 % rH pack to store their coffee?


From the Boveda site

I usually split bags of coffee in to 6-8oz portions and freeze them, so when I take one out it stays out for 4 to 5 days, until it's all used up. Maybe condensation on "frozen" coffee isn't a big deal? But in my experience condensation on room temp coffee is bad news.

I've tried grinding coffee at a range of temps (sometimes intentionally, sometimes not), and have never been surprised by a big change in taste, so I've never tried to do blind testing. It would have to be a noticable improvement to switch to a less convenient (for me) way of storing coffee.

I split my coffee into several 8oz mason jars once it nears its sweet spot. Freezing seems to preserve this flavor quite well. I open the jar each morning and pour out enough for a double then place the jar back into my freezer (kept at -4f). I live in Arizona so condensation will form very quickly, but I figure its like doing RDT and haven't worried about it. Doing this I have not noticed a significant impact on flavor unless it takes me a prolonged time to go thru the coffee. I have never placed a jar of frozen beans onto the counter and then allowed them to thaw and used thru the week as I believe someone mentioned doing this causes the beans to age faster. IDK if that is due to the moisture or a factor of the freeze/thaw cycle.

Tristan, I don't know the answers. In my case I take out the bag, open it, measure out some beans, close the bag and return it to the freezer. That there was essentially zero absorbed moisture surprised me. Where I live is not an especially humid place (60-80% r.h., 60-75°F). So maybe in the tropics my approach wouldn't work well... although if I lived in the tropics I might have an air conditioner.

TrlstanC wrote:I usually split bags of coffee in to 6-8oz portions and freeze them, so when I take one out it stays out for 4 to 5 days, until it's all used up. Maybe condensation on "frozen" coffee isn't a big deal? But in my experience condensation on room temp coffee is bad news.

Yes, the danger from condensation is the rot that happens if it sits on room temperature beans for any length of time. If you grind right away, no problems.
Otherwise, let the sealed portion completely come to room temp before unsealing.

Apologies if I've missed it in another thread, I'm still finding my way around here. Is there any data to support the idea that grinding from frozen might preserve VOC's ? Cheers, Scott

The research from Matt suggests 20 deg C is the critical point so its not necessary to freeze beans for the improvement he is describing.

As a result of reading his research I modified my process, I freeze half a 500g bag and keep the other half in the fridge. Use the fridge bag until its finished then move the freezer bag to the fridge. Grind, Pull & Repeat!

I believe I detected an improvement in my results in the cup after moving to this method, I didn't blind taste though so the results are open to bias.