Freezing Seriously Affects Profile! [Mystery Solved!] - Page 3

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
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TomC
Team HB

#21: Post by TomC »

JohnB. wrote:That is serious over kill if you are using good good quality vac bag stock. I vac bag with the Foodsaver using their rolls & have seen no sign of freezer burn/moisture loss. Some of my greens have been in the deep freeze for 2.5 years at this point. If the bags are holding the vacuum air can't get in & moisture can't get out.
Oh, I know, and I joked about it being overkill and a excessive waste of time, going forward. It was just an experiment, mainly because I don't have a deep freeze that's extremely cold. And I open it up two to three times a day to grab either coffee or frozen fruit for my blended smoothies, and I do get a quite a bit of condensation that quickly freezes on the surface of all my packaging. I live 500 yards from the ocean, and Pacifica is always quite foggy. I can leave my patio screen door open overnight, and the next morning, every surface in the apartment feels cold and ever so slightly damp, mainly right in front of the door.

Anyways, my huge batch of El Salvadorian beans are in the freezer, in a plain old ziplock bag, not even vacuum sealed, no foil or anything.

When those Don Patchi Geisha beans show up, I'll for damn sure be doing the vacuum sealing with foil wrapping though. I think it's worth the extra effort on something that expensive.

Jammers

#22: Post by Jammers »

You should be able to tell visually if the greens are dried out. The usually develop a whitish tinge or spots and a woody or faint-to-non-existent smell. If they are dried out, your roast should proceed much faster than your normal profile and the beans should taste woody, bitter, and/or ashy, not sour.

Have you tried cupping the roasts? That wd provide a lot more information than spro.
"My body remained in this armchair and, I regret to observe, consumed in my absence two large pots of coffee."."

Jammers

#23: Post by Jammers »

The easiest way to troubleshoot would be to see the greens and the roasted. If you want to do a coffee swap (send me your two roasts, one of the frozen and one of the unfrozen and I'll send you some of my espresso), I'd be happy to give you my thoughts. (...for whatever they're worth!)
"My body remained in this armchair and, I regret to observe, consumed in my absence two large pots of coffee."."

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coffee.me

#24: Post by coffee.me »

Benjamin, thanks for your posts. Yeah, they don't match your dried bean description, not in green nor in roast. My current thinking is that those frozen ones absorb heat faster somehow and that's why BT stays on course while ET struggles to go up fast enough(compared to the same bean never-frozen). I have no clue what caused that change in greens. My last batches of the never-frozen was done less than two weeks ago and I don't have any more never frozen of the same/similar bean.

I'm thinking my freezing did something to the greens. No one knows what yet, but to compensate it seems I'll have to reprofile the bean from scratch; a simple heat hike isn't enough change to compensate so far. This is gonna be an important experience since I have lots of great greens in the same freezer.

And thanks for the swap offer, but I'm a bit far from NJ, I'm in Europe :)
"Beans before machines" --coffee.me ;-)

DavidMLewis

#25: Post by DavidMLewis »

While I had not noticed the affect you mention, I have noticed something that may be relevant. We usually monitor environment temperature for two reasons. The first is that it's easy to measure. The second is that what we really want to measure, which is energy being transferred into the beans in real time, is hard to measure and we need a proxy. In a commercial roaster, where much of the energy transfer is convective, environment temperature is a good proxy, and much faster to respond than bean temperature. But in the Hottop, I am convinced that it can be confusing. I am convinced that much of the energy transfer into the beans in a Hottop is through infrared radiative forcing, and much less is convective. I drew this conclusion from my observation that I could have a relatively high environment temperature with the element off or nearly so, especially during first crack, and still have the bean temperature stall. But I could have a much lower environment temperature without stalling if I arranged the roast so that the element was on full as first crack was entered. Perhaps this may help explain what you are seeing. (It's also why, contrary to a commercial roaster, keeping a Hottop's drum and chamber clean is important.)

Best,
David

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another_jim
Team HB

#26: Post by another_jim »

That's a good observation. I've always wondered how much radiation and convection is happening in the Hot top. Maybe a visual of the element, or an ammeter like on the Quest, would be more useful on the Hot top.
Jim Schulman

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coffee.me

#27: Post by coffee.me »

DavidMLewis wrote:While I had not noticed the affect you mention, I have noticed something that may be relevant. We usually monitor environment temperature for two reasons. The first is that it's easy to measure. The second is that what we really want to measure, which is energy being transferred into the beans in real time, is hard to measure and we need a proxy. In a commercial roaster, where much of the energy transfer is convective, environment temperature is a good proxy, and much faster to respond than bean temperature. But in the Hottop, I am convinced that it can be confusing. I am convinced that much of the energy transfer into the beans in a Hottop is through infrared radiative forcing, and much less is convective. I drew this conclusion from my observation that I could have a relatively high environment temperature with the element off or nearly so, especially during first crack, and still have the bean temperature stall. But I could have a much lower environment temperature without stalling if I arranged the roast so that the element was on full as first crack was entered. Perhaps this may help explain what you are seeing. (It's also why, contrary to a commercial roaster, keeping a Hottop's drum and chamber clean is important.)

Best,
David
David, thanks, so much good stuff in the above post. I'm not a native English speaker and I'm not sure I clearly understood your advice, can you kindly clarify (or maybe simplify the language?) on the following:

- YES, my HT's drum and chamber are not clean AT ALL(read: darn filthy)! So you're basically saying maybe "TRUE ET" was decreasing slowly because of the lack of maintenance and I didn't notice until it became so bad now?

- I FULLY agree on the role of element radiation on the HT, I discovered this two years ago the hard way (see my saga here: Charging at a High ET without Tipping/Scorching/Charring?). What isn't clear to me is how's cleanness of chamber and drum related to heat from the element?

Thanks again for chiming in, I'm very optimistic that this will resolve my issue.
"Beans before machines" --coffee.me ;-)

DavidMLewis

#28: Post by DavidMLewis »

Cleanliness affects the Hottop because it affects the reflectivity of the drum and chamber. When clean, the drum and chamber reflect the infrared and more of it is absorbed by the beans. When dirty, they absorb the infrared and become hotter themselves. As Alton Brown once said of ovens, "cleanliness is next to hotliness!" I use espresso machine cleaner on the drum, and Simple Green and a scrubbie on the chamber.

Best,
David

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iginfect

#29: Post by iginfect »

DavidMLewis said:
Cleanliness affects the Hottop because it affects the reflectivity of the drum and chamber. When clean, the drum and chamber reflect the infrared and more of it is absorbed by the beans. When dirty, they absorb the infrared and become hotter themselves. As Alton Brown once said of ovens, "cleanliness is next to hotliness!" I use espresso machine cleaner on the drum, and Simple Green and a scrubbie on the chamber.
Conventional wisdom is that the roasters shouldn't be clean but have a patina of coffee oils etc. I usually use a scrubby and some Oxyclean type product or Urinex once or twice a year and feel that I'm overdoing it. Anyone else have an opinion?
Marvin

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Arpi

#30: Post by Arpi »

iginfect wrote:Conventional wisdom is that the roasters shouldn't be clean but have a patina of coffee oils etc.
Hi.

Patina only helps when it exists in the drum but it hurts any other place. In the outer shell (inner surface of the roast cover), it would be best to keep it shiny so that the radiation is reflected towards the drum and not be absorbed by the walls. So patina would be good for either the outer and inner surface of the drum, but not for other parts of the roaster. For a higher radiation effect, clean the inside of the roaster but not the drum.

Cheers