Posted Sat Apr 14, 2012, 6:07pm Subject: Green bean density, moisture content, de-massing: a plea to the distributors!!
As an obsessive home roaster, I find that I must alter my base profile significantly from one bean type and origin to the next to achieve the same target roast level (City+, Full City etc.) Among the many variables that differ from one batch to the next (bean type, size, shape, process/quantity of chaff, density, moisture content, other regional/growing factors etc.) and the many non-profile factors that affect the roasting process (ambient temperature, actual voltage, pre-warming temperature, bean load in roaster etc.), I’m finding (in my limited experience) bean density to be one of the most important factors affecting the roast outcome for a given profile, or at least one of the most important factors which I can’t easily measure. Actually, as I have no practical method of determining bean density at home (I don’t want to soak my beans etc.), I use grow elevation (when I can find it) as a as a proxy for bean density.
Thus before I roast a new bean, I try to concoct a new initial profile by guesstimating “density” based on descriptions I’ve read, grow elevation if I can find it, vague impressions and other fuzzy stuff. Looking back at my log for “similar” beans helps, but creating a new profile for a new bean is still an iterative and frustrating process. Sure, over time and as my experience bank grows, I’ll probably get a better feel for the different green beans, but I find myself thinking over and over again that the green bean distributors/retailers are in possession of a lot of information which would really help us home roasters if they just shared it. Description of the flavor notes, the joys in the cup that await us post-roast are great, as are the stories behind the beans, but can we also have some data about the beans themselves?
So here is my wish list for the distributor community. When you describe your offerings, also please publish: a) Green bean density b) Green bean moisture content c) Any other data that might be useful to the roaster (average bean size, average chaff as a % of mass, and certainly process method and varietal (Bourbon, Caturra, etc.) which are also sometimes left out of the description…many others I’m sure I haven’t thought of) d) De-massing percentages for the particular bean at a couple suggested roast levels.
I know that a) and b) will change as the green beans age and depending on how and where they are stored etc. So the distributors can simply publish “as of” data. I.e. on 4/14/2012 an average bean density was X and an average moisture content was Y. Yes these variables will drift over time, but at least we’d have a baseline understanding of some of the most important bean characteristics (knowing green bean density may also help us later on when we grind and extract). We could all run out and purchase measuring equipment ($$) but if the distributors already have the data (which they should as part of the buying process) or the tools to easily measure them (which they should), it should be no skin off their backs to share it.
I haven’t talked about moisture content, and I don’t have hard data to back me up, but intuitively, it would seem likely to affect heat propagation and the drying time in the profile.
De-massing percentages are another personal obsession. For those of us without official Agtron scales, we don’t have an easy way to compare one roast (of the same bean) to another, and no precise lingua franca when speaking to fellow roasters about a given bean (as an aside, I believe de-massing percentages also help establish (kind of) an apples-to-apples basis when we want to compare the taste of different roast profiles/path-dependencies for the same bean and target roast degree.) The classic categories (City, Full City etc.) are very broad blocks and, in my mind at least, ill defined. When does first crack end – and for that matter when does it begin (at the first pop, the second?) There is a big difference in the cup even within one category taken say 2.5minutes past the start of first crack, and 3 mins. I find a pretty good intuitive correlation (and reproducibility) between de-massing percentages (1-(post-roast weight/pre- roast weight)) for a particular bean, and my interpretation of roast level. Profile I’m sure will affect the relationship between de-massing and roast level, but again, if the distributors would give us a sample de-massing number for a target roast (specific to the batch of course), we’d have another guidepost as to whether we are approaching on-mark or not. For example, instead of saying “wonderful at Full City”, they could say “wonderful at FC, which we found to be around 13-14% de-massing”.
Apologies for the rant, but I’ve had this pent up for a while. I’m a noob, so my voice probably doesn’t carry much weight. I’m hoping that someone who does have a voice in the community comes across this post and decides to champion the cause of more data (any data!) from the distributors – data will help us become better and more systematic home roasters. I’ve seen the power of these forums – the industry does pay attention! Does anyone else agree we need more info from the distributors about our green beans?
Snaxx Senior Member Joined: 11 Dec 2008 Posts: 115 Location: Northeast Michigan, LP Expertise: I love coffee
Grinder: KitchenAid A9 Drip: Technivorm Moccamaster Roaster: I Roast2
Posted Sat Apr 14, 2012, 7:40pm Subject: Re: Green bean density, moisture content, de-massing: a plea.....
You seem to be asking for more than is possible to logically provide or need. The variables in beans will also be affected by the variables in each roasting method, and even between different roasters in a manufacturer, as well as voltage to the roasters if electric, and probably even gas fired would have a variable. What about BBQ roasters, pan roasting, or popcorn poppers? How is a supplier supposed to provide standard information if every roaster or method is so variable? Even the quantity of beans in a roast is a variable.
With my I-roast, I find that to reach a certain level of roast, I'll always use the same amount of beans, usually an 8 oz. load, and roast that to an approximate time before I dump and cool. If I reduce the amount by half, then that changes everything and it will take less time to complete a roast. I bought a spare I-Roast last year and that roasts totally different than the one I use every week, so how would knowing a bunch of parameters a supplier tells me his beans have, help me produce a better medium roast? Another point with the I-Roast, you can't hear the cracks, so you just have to view the beans and learn where you are by color, and once you figure out what level of roast you want, then you can get pretty close for each roast using time.
I think the best anyone should hope for is a description for the roast level to reach; light, medium, dark, city, full city, or whatever, that the bean supplier has described for flavor notes of the cupping. With the beans I buy from Klatch, they list on the bag the roast level they roast to for each variety. For other suppliers, it's just a variety name on the bag and that's it.
None of the information you're asking for means beans to me, as I don't know how I'd incorporate these bean parameters into a roast session. Ken
Posted Sat Apr 14, 2012, 8:23pm Subject: Re: Green bean density, moisture content, de-massing: a plea.....
Hi and thanks for the comment. I'm really asking for two categories of information, a basic set of quantitative bean descriptors (this should be easy to provide) and one somewhat subjectively derived result (% de-massing the retailer achieved at the recommended roast degree).
The data need not in any way be tailored to a specific machine or method. That is the beauty of it. You have your machine, voltage, roast method etc, I have mine. However, when I plan a roast, I know my machine and methodology, and can to a certain degree control these things, ie if I control properly using the same load weight, pre-heat, roast profile, voltage etc, the biggest variable (maybe) becomes the bean. Knowing the properties of the bean can hopefully help us better predict the outcome of a roast recipe - that is the fun of it! You would have your own set of standard roast parameters for your set-up which you control, and you'd see a different impact due to the bean hardness than I would, but the results would be consistent in your roast framework and could potentially help you to fine tune your roasts.
That said, all machines have their quirks and limitations. I've never used an I-Roast, but if you aren't actively controlling the temperature during the roast process and are primarily controlling the load weight and roast time to dump, then a lot of this information may be irrelevant to you. But if you are playing with the temperature profile during the roast, many of these variables become interesting. For instance, you can get to C+ by setting on high and blazing through to an early dump, or roast at a more moderate temperature for a long time. Color may be the same between the same bean roasted to C+ using the two different methods, but the taste will be different. Figuring out which temperature/time/(pressure etc.) recipe tastes best is the joy of profiling. I really would like to know what commercial roasters spend time analyzing before they throw their beans in the roaster! Cheers,
Posted Sun Apr 15, 2012, 4:49am Subject: Re: Green bean density, moisture content, de-massing: a plea to the distr
If you really want bean moisture you could procure a 'Moisture Meter' typically used to measure moisture in agricultural grains such as wheat, oats and corn. look here. For even lower moisture levels you can find similar instruments used with granulated plastics. You just shove them in the drum (or bag) and in a few moments you have a moisture level.
germantownrob Senior Member Joined: 2 Dec 2007 Posts: 2,017 Location: Philadelphia Expertise: I love coffee
Espresso: Duetto 3, A Dead Oscar Grinder: Vario-W, Preciso w/Esatto,... Drip: Brazen Roaster: Diedrich IR-1, HT B
Posted Sun Apr 15, 2012, 5:56am Subject: Re: Green bean density, moisture content, de-massing: a plea to the distr
By doing a basic profile roast for a new bean or even a bean that has been in my storage for a while I can gather most information on my own, from this I adjust the profile to achieve what I am after. Things like roast loss can be altered by how you get there, short vs long drying phase, short vs long ramp to first, short vs long finish ramp to the same roast degree. I do know a roaster with the same machine as me that strives for the same roast loss to Full City for everything he roasts for espresso and he will make adjustments to the profile to achieve this.
Knowing exactly where you are for roast levels is much easier when using a bean mass probe, using just your senses to judge city, city+, and full city (especially when not allowing any pops of second crack to happen) is tricky and much less precise but still doable with in reason.
What drives me mad when purchasing greens is not knowing arrival date of a particular bean. sweet Maria's is a place that posts that for every bean in stock, other places may have it for some beans but for other ones you may be getting the previous years harvest. For me it is very important to get beans soon after their arrival, a super fruity bean will degrade considerably in 3 months and no matter how you roast it you can not get the flavors back once it has crossed this line. So when I purchase these beans they have to be a new arrival and then I deep freeze them to be able to preserve the super fruit to enjoy for the rest of the year (sometimes for more then a year).
Posted Sun Apr 15, 2012, 10:34am Subject: Re: Green bean density, moisture content, de-massing: a plea to the distr
Agreed, the retailers would be doing us a great service by posting harvest and arrival dates. Because we don't have a lot of information (or maybe because the nature of roasting is just too complex?) I think we all take the same approach, run a profile, see how it comes out, then adjust. I'm not saying we'll ever escape this way of going about the roasting and discovering what profile works best for a given bean and target roast. Just that it would be great to know more about the bean so we're not flying blind initially and in the hopes that knowing some of the bean characteristics can help point us in the direction of a great profile (and maybe help us better understand the bean and roasting in general).
Yes, I could buy a moisture meter, but why when the retailers already have the moisture content information and could simply post it? Moisture content is one of the key things they measure in a new bean.
Yes, the probe would be a huge jump. I currently lust after a Quest (saw it in action at one of my friend's homes). That gives you the probe for BMT, ET, control over airflow, amps...approaching what a commercial roaster has. HotTop w/panel might do the same. Roasting is such an interesting hobby, so much to learn, so many great technologies, so many neat mods and techniques the community has developed.
Posted Sun Apr 15, 2012, 10:37am Subject: Re: Green bean density, moisture content, de-massing: a plea to the distr
GermantownRob - sorry this is off-topic, but how are you freezing your green beans? Do you need to use a vacuum bag, and if so, do you have recommendations?
Posted Sun Apr 15, 2012, 12:02pm Subject: Re: Green bean density, moisture content, de-massing: a plea to the distr
For those of us who have Behmor roasters, we are encouraged by Joe to use the 'Rosetta-Stone' rule in his manual.
What it recommends is that after the onset of the 1CR, if you continue the roast by (say) 2:15 min (changes with roast weight) and then go to cool, you will get an acceptable roast. If 2:15 min is too light you might make it 2:30 next time.
What he is saying is that the CRITICAL VARIABLE is the length of time beyond the 1CR. By then, all the drying has already been completed and 'moisture-content' has been cancelled out as a variable.
Snaxx Senior Member Joined: 11 Dec 2008 Posts: 115 Location: Northeast Michigan, LP Expertise: I love coffee
Grinder: KitchenAid A9 Drip: Technivorm Moccamaster Roaster: I Roast2
Posted Sun Apr 15, 2012, 12:09pm Subject: Re: Green bean density, moisture content, de-massing: a plea to the distr
aaronotb Said:
Yes, I could buy a moisture meter, but why when the retailers already have the moisture content information and could simply post it? Moisture content is one of the key things they measure in a new bean.
Moisture content is a major variable. Of course they will be dried down to a certain moisture content before bagging so mold doesn't set in from beans that haven't dried enough. That's probably why they measure it then to make sure it's low enough so it can't mold and contaminate every bag in the warehouse. But since you're dealing with a cellulose material which gains and loses moisture very readily, moisture content will vary all along the chain of supply and storage locations over a period of time. If the warehouse maintains a certain temperature and humidity level for storage, over a period of time, those beans will become acclimated to that environment, and if they check the moisture content on the day they arrive at the warehouse, it will be "X". Over the period of time from when they are received and stored, up to the time they are finally all shipped out, there will likely be some variation from "X".
germantownrob Senior Member Joined: 2 Dec 2007 Posts: 2,017 Location: Philadelphia Expertise: I love coffee
Espresso: Duetto 3, A Dead Oscar Grinder: Vario-W, Preciso w/Esatto,... Drip: Brazen Roaster: Diedrich IR-1, HT B
Posted Sun Apr 15, 2012, 1:40pm Subject: Re: Green bean density, moisture content, de-massing: a plea to the distr
aaronotb Said:
GermantownRob - sorry this is off-topic, but how are you freezing your green beans? Do you need to use a vacuum bag, and if so, do you have recommendations?
I use a food saver vacuum, had it for over 5 years and it is still going strong. I make up 2 lbs packages since that is my batch size but one thing I stopped doing was to pull a strong vacuum, all it takes is one sharp edge of a bean to poke a hole in the bag. I also store in a deep freezer at -5f to -10f.
Symbols: = New Posts since your last visit = No New Posts since last visit = Newest post
Forum Rules: No profanity, illegal acts or personal attacks will be tolerated in these discussion boards. No commercial posting of any nature will be tolerated; only private sales by private individuals, in the "Buy and Sell" forum. No cross posting allowed - do not post your topic to more than one forum, nor repost a topic to the same forum. Who Can Read The Forum? Anyone can read posts in these discussion boards. Who Can Post New Topics? Any registered CoffeeGeek member can post new topics. Who Can Post Replies? Any registered CoffeeGeek member can post replies. Can Photos be posted? Anyone can post photos in their new topics or replies. Who can change or delete posts? Any CoffeeGeek member can edit their own posts. Only moderators can delete posts. Probationary Period: If you are a new signup for CoffeeGeek, you cannot promote, endorse, criticise or otherwise post an unsolicited endorsement for any company, product or service in your first five postings.
= No New Posts since last visit 