PS

Still need to personally taste test shots from beans that have been: a) vacuum sealed and frozen, then thawed to room temperature while still sealed, vs b) beans that have been vacuum sealed and not frozen, vs c) beans straight from the roasters bag. All with the same rest time. I sure hope that I do not notice a significant difference between c) and a) or b), as I do like to buy more than 1 lb at a time.

JHCCoffee dedication. I also only drink decaf now and the health benefits for me personally have been tremendous.

    tompoland thanks for taking the time to post. I know that can be quite time consuming.

    Happy to give back a fraction of the good advice and information I’ve received from this board.

      11 days later

      Ran a series of side by side taste tests with:

      A) two 100g vacuum sealed bags of beans that were vacuum sealed the prior day, after 2 weeks rest in their original bag. The first 100g bag of beans was then decanted into 6 mini jars that hold 18g, which have a cork plug. The jars were filled to the brim and then closed with the cork plug.

      B) two 100g vacuum sealed bags of beans that were vacuum sealed after 2 weeks rest in their original bag. These were subsequently frozen, for 1 day. One bag was then removed from the freezer the evening before the test and defrosted overnight. The next morning, the defrosted beans were decanted into the above mentioned glass jars.

      I tasted a pair of never frozen vs frozen then defrosted bean jars (18g per) every day. Each pair was ground and poured in the same manner. However I did vary the brew ratio from day to day, as I was testing the affects of various brew ratios on taste. But the paired shots were always ground and poured in the same way.

      Once I worked through one set of 100g bags, I would work through the next set.

      I noticed that the never frozen shots initially tasted just slightly (oh so slightly) better than the frozen then defrosted shots. By better I mean more body, strength, taste extraction and length. But just slightly.

      However this barely detectable effect (of the never frozen beans tasting just barely better than the defrosted beans) only lasted a day or at most two. By the end of the week, there was a discernible difference between the never frozen vs defrosted beans. This divergence continued and widened with the next paired 100g bags of beans, with the never frozen beans declining further, as if they were staling.

      This divergence should not have occurred, as the never frozen beans were apparently decently vacuum packed using an inexpensive home vacuum sealing machine.

      I conjure that once the never frozen beans beans left their original bags (which were sealed one pound bags with one-way valves), they were exposed to oxygen and began an irreversible decline. Moreover the vacuum packing process did not likely remove all of the oxygen. So the beans continued to stale in the vacuum sealed bags. This staling likely accelerated upon the opening of the vacuum sealed bags, and their decanting to the jars.

      At the end of the 12 day series, I was effectively tasting 12 day old (stale) beans vs 6 day old defrosted beans. I had to throw out the never frozen beans, as they were too stale.

      Conclusions:

      • While freezing beans might cause a very slight loss in the potential to extract good shot body, strength and taste, this is over shadowed by the preservative benefits of freezing beans.

      • By comparison, once you open a bag of never frozen beans, they will begin to stale, even if you reseal them in vacuum bags (with my home vacuum sealer). Once you open the vacuum sealed bag, the staling process will accelerate, even if you decant the beans to well sealed glass jars.

      • The only time that never frozen beans taste better than defrosted beans, is when the original bag of beans is opened, after 2 weeks rest. After that, taste goes gradually downhill.

      So, I will be freezing my beans in 100g vacuum sealed packets, after 2 weeks rest. And then decanting a single defrosted 108g packet into six 18g jars, but with silicone rubber stoppers.

      All of the above is subjective and not perfectly scientific, but its good enough for me.

      PS. The beans were a blend of decaf Hawaiian and decaf Espresso blend (⅔ Hawaiian and ⅓ Espresso blend), roasted by Goldstar coffee.

        JHCCoffee I conj[ect]ure that once the never frozen beans beans left their original bags (which were sealed one pound bags with one-way valves), they were exposed to oxygen and began an irreversible decline.

        With apologies for any offence, but I very much doubt that the simple act of opening a bag, thus exposing the beans to oxygen, and then ‘quickly’ re-sealing and vacuuming the contents is significantly deteriorating the beans “because they have been exposed to oxygen”.

        Beans are roasted at temperatures in excess of 200 °C - well above the melting temperature of the plastics used to vacuum pack them - and release a lot of CO2 just after the roasting finishes, so they need to be cooled down and left to de-gas. It is possible that industrial roasters of the scale of the big guys will do this in inert atmosphere, but the small roasters that we all seem to like and prefer will do this in air. This will leave a highly reactive, just roasted bean exposed to air for several hours.

        Whatever oxidation reaction happens once the package is open for consumption happen at ambient temperature - and thus at a significantly lower rate - and in a matter of minutes if the package is re-vacuumed (and at a further reduced rate if the temperature is lowered by freezing).

            CoyoteOldMan I agree that a lot of O2 degradation happens after roasting…so I try to pack them whilst still warm 😁. As I use food safe mylar without valves, this has the benefit of warming the air in the bag. When I squeeze most of the air out to heat seal, the expanded warm air cools and contracts, this minimises the 02 in the bag and they almost look vac packed.

            The beans release a little CO2, but not nearly as much as in a valve bag and remain fresh for a very long time so much so that many of my YT shots overflowing with cream are from 2 or 3 month old beans!

            My belief is oxygen degraded beans rapidly, especially after roasting. Additionally, even brief exposure to air allows a certain amount of oxthen to adsorb onto the surface layer of the bean.. which is porous. So staling continues after resealing.

            Contact me

              CoyoteOldMan Whatever oxidation reaction happens once the package is open for consumption happen at ambient temperature - and thus at a significantly lower rate - and in a matter of minutes if the package is re-vacuumed (and at a further reduced rate if the temperature is lowered by freezing)

              No offense ever taken, CoyoteOldMan. I always welcome your ideas and thoughts. What may have been happening was that I was not removing enough air from the vac seal bag, as: a) my vac seal machine is inexpensive and does not generate alot of vacuuming pressure, and b) I stopped vacuuming once it looked like the air was removed from the bag, possibly with the unfounded concern of vacuuming to much. So I suspect that some air remained in the bag, between the beans. So the bag may have looked vacuum packed but wasn’t fully.

              Which means that I should vacuum longer/more fully, or that I need a better vacuum pack machine for Christmas. 😁