DavecUK definitely think it’s stealing and possibly changes caused by freezing

I do think it’s time for me to do some personal taste tests: using the same coffee, same recipe, vacuum sealed single dose bags: frozen bags vs not frozen, and see what my non-expert taste tells me. The various studies that I read say it’s fine to freeze and then defrost beans, as long as you let them defrost and warm, before unsealing. Other studies crow about the benefits of grinding from frozen.

Time to give my personal taste buds a whirl.

7 days later

Grinding from Frozen Vs Unfrozen Update

I have been running a series of tests, using the same beans, same grind, same dose, same basket, same temperature, same pre-infusion, same brew ratio. Just grind from unfrozen vs frozen. The beans were stored in very small sealed single shot jars.

I have done 4 sets of paired shots thus far, over a number of days. In virtually every case, the frozen shots ran significantly faster. Like 15 seconds faster!

And …. every ground from frozen shot had slightly but noticeable less body and less strength than the ground from unfrozen shots. And the ground from frozen shots were noticeably more bland.

I then poured two sets of unfrozen vs frozen shots, but went to a one number finer grind on my NZ for the ground from frozen shots. In both cases, the flow times were close to the same.

And in both cases, the ground from unfrozen shots had somewhat more body and strength. And the ground from frozen shots comparatively tasted a tad bland.

Conclusion: From this very unscientific test. I prefer the taste of ground from unfrozen shots.

Other Changes

I’ve also just now been changing a couple of things in my dose and distribution. I improved my WDT technique to use the small circle moves that Lance Hedrick demonstrated in his video, which eliminated the holes that I frequently seen in the top of my puck.

I also tried 18.0g in my 18g IMS basket (see headspace analysis below), using beans that have not been frozen, with better WDT technique. All while maintaining the same brew ratio of 1:1.5.

The Result: Good body, good strength, decent flavour emerging and decent length; my best tasting shot (with my Lelit E and NZ) to date.

Getting there.

Might pop in my IMS screen and grind finer, just to drive me nuts 🤪

And Headspace

I used calipers to check the headroom that I have, using my IMS 18g basket on my Lelit E, and my current City Roast decaf blend. I measured that there is 9.5 mm from the top of my basket rim to the bottom of the flange on my bottomless portafilter. I also noticed that the top of the spiral that holds the portafilter on my Lelit E is even with the screen. So a fully tamped puck that is 9.5 mm below the rim of my basket will touch the surface of the Lelit E screen. Or so it seems.

Accordingly, if I add 2.0 mm (the thickness of a Canadian nickel) for headspace, the top of my fully tamped puck would need to be 11.5 mm below the top of my basket rim.

As my basket has a 22.1 mm interior depth, my puck depth (top to bottom) should ideally be 10.6 mm. Supposedly.

Interestingly, if I load this basket with 18g, I get: about 10.3 mm of puck depth and 2.3 mm of headroom. Give or take.

So maybe IMS designed their 18g basket to fit 18g and allow for sufficient headspace. Duh 🙄

Why all this faf? Just wanted to see how much headspace I was getting. I’ve been dosing 16.5g in my 18g basket, in order to allow for sufficient headspace. I now realize that I can easily dose 18g, and probably still get sufficient headspace.

    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.

        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. 😁