Baby roaster and similar - compared to the Gene

[luisneumann]

Re: Baby roaster and similar - compared to the Gene

Random thought.
Have anyone notice a difference in the post roast mass loss when using an open and a "closed" (wet) roaster under a similar temperature profile? In a wet roaster, there will be a significant amount of water vapour in the chamber, and for the same temperature and pressure, one could expect less water  leaving the beans - the water in the beans needs to be in equilibrium with the vapour phase. In an open roaster, such an equilibrium is unlikely to occur. The increased amount of water in the beans may affect the rate of reactions in the wet roasting. In an open roaster, these rates may be lower and hence a few days are needed for them to be completed.

[sidewayss]

Re: Baby roaster and similar - compared to the Gene

The one way valves do their job by releasing gas including O2 and CO2 from bag to outside. What it doesnt do is expel all of the gases due to its passive design.

Beans will still stale due to time, and contact with residual oxygen in the bag, but since external air is minimized, beans will stay fresher in bags with one way valves.

What i would like to do is  a weigh in of greens and browns in both the coretto (open system) and the FZ-RR 700 (closed system) in the near future and post the results here.

Because the beans from the baby roaster has a higher moisture content due to its closed system, i will also divide a roast into two lots, both into bags with one way valves, but one of those will have dessicant/moisture absorbing sachets in one of those bags, and note the flavour in the cup to see if theres any differences.

Perhaps someone here would like to do the same on a open system like the Gene and post results, that would be great.

Whatever the result, everyone should endeavor to roast enough beans for their requirements and use within 3 weeks.

Gary at G

[lindsayra]

Re: Baby roaster and similar - compared to the Gene

My instincts tell me that a coffee bean roast at temps over 200C then cooled from either a closed or open roaster will have similar concentrations of water in the cooled beans post roast, since the very hot beans having lost their water during the roast are similarly cooled in air (21% O2, 78%N2).
I think that any differences in the flavour of the post roast products will be due to the conditions during the roast, relative oxygen, nitrogen and water vapour concentrations.
The aging of the post roast beans from a low O2 roast may have higher concentrations of retained unoxidized flavour compounds, so flavour development during aging may be different from a high O2 roasts.
I suspect that more attention to the O2 and water concentrations during storage are likely to be the major effectors of post roasted bean quality lifespan etc.
Storage over activated silica gel would be a way of providing an environment low in its water content.
Storage in a low O2 environment may be illuminating, possibly generated by treatment of air with a wet steel wool pad.
Storage under N2, CO2, helium etc. may yield interesting results but require specialised equipment and time and probably better left to a laboratory.
Perhaps Dr Illy’s work and others may already have these questions answered, somewhere.
Like most CSrs my own post roast storage is a compromise, where convenience is heavily weighted and since I’m content with the results I’m also unmotivated to experiment any further.
Lindsay

[Dimal]

Re: Baby roaster and similar - compared to the Gene

Nice one Lindsay.... [smiley=tekst-toppie.gif]

Mal.

[flynnaus]

Re: Baby roaster and similar - compared to the Gene

Nice one Lindsay....

Yes, another vote from me. I think tweaking the roasting process is more important for home roasters It is hard to go past the 1-way valve for general storage - just make sure it is sealed properly and invest in a heat sealer - you can pick them up for less than $50. Using nitrogen or helium flushing is an extravagance and will only last as long as the first time you open the bag.

Congrats on the Gold Star Mal. More than well deserved if I might say so.

[KJM]

Re: Baby roaster and similar - compared to the Gene

Storage in a low O2 environment may be illuminating, possibly generated by treatment of air with a wet steel wool pad.

Now that is a cunning idea. I wish Id thought of that before! (Not for coffee : In another context )

/Kevin

[Dimal]

Re: Baby roaster and similar - compared to the Gene

Congrats on the Gold Star Mal. More than well deserved if I might say so.

Aw shucks.... :-[

Thanks Steve. Andy calls it my Sheriff Badge.... :P

Mal.

[flynnaus]

Re: Baby roaster and similar - compared to the Gene

Andy calls it my Sheriff Badge....

Got that everyone? From now on, dont say "Ask Mal, hell know", say "Yer better holler for a marshal!"

[sidewayss]

Re: Baby roaster and similar - compared to the Gene

Belated congrats on yer badge Sheriff

In response to luisneumanns enquiry, i have done a weigh in of greens prior to roast at 200gm.
Browns after roasting came to exactly 170 gm on the closed system of the baby roaster.
I dont know how to work out the resulting percentage, perhaps someone can help me out?
Roast profile was at C8-C9.

I believe the moisture content of a closed system would be higher, so i conducted a simple test by dividing the end product into two individual bags. One with silica gel inserted. One without.
Will report back in a few days the cupping notes.
This test i did after reading Lindsays post.

Would be good if someone can conduct and do the same weigh in before and after as well as try out the silica gel test on the Gene or similar "open" system for comparison.

Gary at G

[Dimal]

Re: Baby roaster and similar - compared to the Gene

;D ;D

"Howdy yall...." He says swaggering through the saloon doors while tipping his hat :P

Anyway :

In the example above Gary, you divide the Difference by the Total and multiply by 100 to bring it to a percentage. A la...

30/200 x 100 = 15%

Which, as it happens, is a fairly average moisture loss number and probably on the lower end of the scale.

Will be interesting to read your results at the completion of your experiment....

Mal.

[sidewayss]

Re: Baby roaster and similar - compared to the Gene

Thanks for the formula Jarn Wayne.

Am surprised at the 15% result. Was thinking it may be more like 13-14%. Its a "closed" system but its not a enclosed system. Theres quite a bit of smoke coming out of those 3 holes of the baby when roasting.

Cupping notes on Sunday once it;s rested for a week.

Luisneumann, perhaps you can offer your services and do the same test on the Gene for comparison?

Gary at G

[luisneumann]

Re: Baby roaster and similar - compared to the Gene

Happy to run a batch through the Gene - you say CS8-9? Which beans did you roast? Ill use the same if I have at home as it would make for less unreliable comparison.

[sidewayss]

Re: Baby roaster and similar - compared to the Gene

Yes. Pulled the roast off the heat quickly when i heard the first few signs of second crack happening.

I used 50gm Brazilian pulped natural
50gm Peru
50gm Ethiopian limmu
50gm Mysore nuggets

Also if you dont mind, if you got some silica gel or some moisture absorbers, could you store the beans evenly divided into two bags, one with the gel, and one without, and then test those beans after say 7 days if any diffferences in flavour.

Ill be reporting my findings this Sunday.

Gary at G


to make up 200gm.

[KJM]

Re: Baby roaster and similar - compared to the Gene

Also if you dont mind, if you got some silica gel or some moisture absorbers, could you store the beans evenly divided into two bags, one with the gel, and one without, and then test those beans after say 7 days if any diffferences in flavour.

Thats exactly what I was planning on doing, but itll be next week - this weekend will be spent off-shore on a fishing charter 8-) (Arent birthday presents wonderful!)

/Kevin

[>CoffeeRoasters]

Re: Baby roaster and similar - compared to the Gene

Mark from C.R.A. might pick up on this thread and offer some insight....

Havent had much free time to surf the Snobs chat rooms at the moment Mal but did pick up on this thread just before. Good to see some experimentation happening and people formulating their own ideas.

There is a lot going on chemically during the roasting process. The post from Lindsay is kind of getting closer to what I believe, some good ideas there. I have had this type of discussion with a couple of people I know in the industry who are more involved with the lab side of coffee and basically our conclusions are that the different roasting environments alter the chemical composition of the beans in different ways.

It is much more noticable when you take things to the more extreme like roasting with full convection to roasting with almost none. There are quite dramatic differences in the end result. Then you can break it down further with experimenting with different combinations of these at different points in the roast profile and also with different heating systems and material and you will notice different results. To make sense of it though you really need to understand the equipment and green coffee and the reactions that take place when roasting. I will be doing a talk at the CS conference in Melbourne on how you can apply some of the science of coffee to the roasting process. Some of you here may find it interesting and it will go well with Andys and Josephs talks.

Moisture is not everything....cell wall structures and bean density all play a part in the escaping of gases during and post roast. Same with sugar and oil retention and levels of caramelisation. For people that havent done much roasting, look at what you do in the kitchen with other foods and cooking instruments. I think that is one of the best references as so much of that knowledge can be transfered into roasting coffee.

Look forward to reading some more of the findings in this post.

Cheers, Mark