Learning to Roast with Small Batches on Larger Roasters

Discuss roast levels and profiles for espresso, equipment for roasting coffee.
Moxiechef
Supporter ♡
Posts: 579
Joined: 9 years ago

#1: Post by Moxiechef »

So, I'm looking at starting to roast. My end goal would be to be able to start a little business for my wife having a stand at a farmers market(She spent 12 years with Caribou in the heart of the "2nd Wave"). We would take a GS/3 for espresso drinks, do pourovers, sell cold brew and whole beans(take a bulk grinder too).

Eventually, we'd probably sell about another 20# a week or so to one of our restaurants for espresso and a few friends and such.

I've never roasted a bean in my life but I've been a chef/cook/restaurateur for the last 30 years. So, I'm decently confident that I can learn the craft somewhat.

I currently have two used roasters I'm looking at. One is a USRC 1#er and the other is a Diedrich IR-2.5, which specs say can roast from 250g to 2.5K. I'm sure that as the business grows, I'd wish for a larger roaster BUT in the beginning, I want to be able to learn to roast without wasting a lot beans. So my big question is, can you successfully learn to roast on the IR-2.5 in 250g or 500g batches? If not, then I think I'll lean towards the USRC 1# and sell it once I gain some roasting skills.

Thoughts??

Thanks,

JB

User avatar
keno
Posts: 1409
Joined: 18 years ago

#2: Post by keno »

You can learn to roast with smaller batches but depending upon how small and the design of the machine your probe readings may become especially sensitive to changes in temp and airflow, unreliable, or you may not get bean temp readings at all if the probe isn't in the bean mass. But even so you can learn about the phases of roasting and learn how to roast by sight sound and smell - which is an important part of learning how to roast. Then, as you get more comfortable with it, you can switch to roasting larger batches.

Be aware however that the techniques and how you control the roaster can be vastly different with smaller and larger batches in terms of: charge temp, gas, airflow, and time. Therefore most roasters I know stick to a batch size that works well for their machine (often about two-thirds to three-quarters of the nominal size rating) as it allows them to consistently control the roast profile to get the results they want.

Advertisement
9Sbeans
Posts: 251
Joined: 9 years ago

#3: Post by 9Sbeans »

JB,

I'm in the North East Ohio area, and I have a 1-pound commercial roaster. You are welcome to try it out during the Christmas-New Year holiday break. Just send me a PM. 8)

I only roast for my own family consumption and a few friends. If you have plan incorporating coffee roasting into your current business, you have to consider your own "acceptable" hourly wage. To me, I would only consider a roaster with capacity greater than 4-kg.

Oh, BTW, I'm confidence that the experiences I gained from my current sample roaster can be easily transferred to the bigger roasters.

User avatar
drgary
Team HB
Posts: 14348
Joined: 14 years ago

#4: Post by drgary »

I agree with the feedback you've been given so far.

If specs say the IR 2.5 can roast as little as 250 gm that is probably so, and there may be instructions with that roaster on how to do that. Can the seller demonstrate its operation at that charge weight?

I have been able to take my 1Kg North TJ-067 (capable of 1.5 Kg) down to a 148 gm batch, but that was pushing the envelope and relied on my having installed a bean temperature thermometer bent down to nearly touch the bottom front of the drum. But perhaps the Diedrich is designed to be able to sample roast.

I would offer this caution, though. As you experiment with roasting you will "waste" some beans because tuning a roast to professional levels - and learning your roaster - takes practice and study. As I dare to learn anyway I consume my off batches with milk and sweetener and tune brew temperature to get the best extraction. I'll add that having a subpar roast is a useful lesson in itself, since it can demonstrate in an exaggerated way how an adjustment affects flavor.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

edtbjon
Posts: 251
Joined: 9 years ago

#5: Post by edtbjon »

If you're aiming for getting consistent professional results from whatever machine you decide to buy, it's better to learn how that roaster works and reacts at "optimium" to full charges. Roasting minimal charges is a different kind of roasting and the roast (i.e. what happens in the bean mass) reacts quite different from say an 80% capacity charge.
If you compare the cost of a Diedrich (even an old used one) to a bag or two of decent quality beans, the math is quite simple... Just get decent beans that will reflect what you're doing with the roast, because (just about) the only way to tell roasts apart is to taste them and compare. (There are lots of good coffee to be found at good prices. You don't have to learn the roaster on a CupofExcellence coffee, but it sohuld be a coffee that you can taste, drink and serve over and over again.)
Take a look on the very educational videos from MillCityRoasters, as there's a lot to learn. They have gotten this very question many times and it's also answered in the videos on numerous occations. (The answer is the "same" as mine btw.)

The best of luck and fortune to your future business. Let us hear about your progress.

User avatar
drgary
Team HB
Posts: 14348
Joined: 14 years ago

#6: Post by drgary »

There is one caution where I disagree. I don't think someone with a capable roaster needs to learn using batches of the same size. You do want to minimize variation while learning, of course. I think you can get to know the roaster with perhaps two different size batches. While just learning how to roast, you can standardize on a small batch within that roaster's known range. Then you can learn the roaster with production-size batches. Using the same coffee roasted for small and large charge loads, you can discover how to make those similar with a coffee you've already dialed in as a sample. If someone really needs to do many small batches that closely approximate production roasts, some companies make sample roasters to go with their commercial machines.

Speaking to Jonathan's anticipated use of the roaster for farmer's markets and one restaurant, if you fall in love with roasting and others like your coffee, you may want to scale up beyond this initial choice. Either roaster you're considering should have decent resale value.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

User avatar
Boldjava
Posts: 2765
Joined: 16 years ago

#7: Post by Boldjava »

drgary wrote:...I don't think someone with a capable roaster needs to learn using batches of the same size. ...
I go in a different direction. You may be forgetting how much you know!

I teach using full charge size. I encourage novices to master full charge size and work their way down to sample size, .1K at a time. Once master, drop another .1K.

There are, IMHO, too many variables to control, to learn, to master before jumping in with another charge size which creates an entirely different BTU application, less mass resistance to airflow, different RPMs, etc. Adding another variable i(charge size) into that mix isn't the best approach. YMMV.
-----
LMWDP #339

Advertisement
User avatar
drgary
Team HB
Posts: 14348
Joined: 14 years ago

#8: Post by drgary »

Dave,

I'm glad you joined the thread, because I just watched your Roaster School videos through the roast stages yesterday. I was thinking about your advice there to standardize on one batch size, and I almost cited my disagreement with your suggestion in my previous post here.

To put this in context, everyone: Dave doesn't boast about it at all, but I think of him as an expert cupper with years of experience, and a roasting educator, also with years of experience. He does this all the time now at Mill City, and I'm a part-time hobbyist, so if you are wondering between taking his advice or mine, take his.

For the sake of discussion, though, Dave, on my North, I've become comfortable with 750 gm charges as standardized (before I saw your suggestion of 1 Kg on a North). I've also become comfortable at 350 gm. And I'm getting comfortable at 1.5 Kg now that I've bought my higher pressure regulator from Mill City.

Each batch size needs to be tuned in. But I could see learning my roaster at a minimum comfortable batch size. If I were working with the Diedrich, for instance, I would contact other users and get their advice. I might hypothetically decide on a minimum comfortable charge of 500 gm. Then I could learn roast basics at that size and only at that size. That would teach me basics of roasting. Then I might go for a recommended charge of 80% of advertised capacity of 2.5 Kg. I would then learn the roaster at that size, but having learned the basics of dialing in a roast at 500 gm., I would know something about tuning the roast for the new batch size.

Perhaps I differ in these ways. I think of learning roasting from start to production in several phases. I am also comfortable at not trying to perfect any one part of my learning process, but to dare to waste some beans and learn from large mistakes, such as thoroughly baking a roast.

I list the phases in a linear order, although I think hands-on experience teaches has the potential to teach about other phases during earlier ones.

1. Learning basics. What are the stages of the roast? How will the beans change through the stages? What are the sensory cues, and how to they correlate with measurements?

2. Learning to fine tune a roast. This can be done at the same, consistent batch size as in phase 1, as long as your roaster can handle that reliably.

3. Learning to use your roaster throughout its capacity range. This might take you down to very small samples and up to and maybe exceeding advertised capacity.

4. A fourth stage that I may never encounter is using your roaster for production. That would involve automation, fine tuning for moisture content, room temperature, aging of beans, etc.

The strategy I'm playing with, here, reduces the amount of coffee used at the first and second phases. Turning this back to Dave and others, does my approach seem unreasonable or that it would slow the learning curve and objectives stated by Jonathan in his originating post?
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

Moxiechef (original poster)
Supporter ♡
Posts: 579
Joined: 9 years ago

#9: Post by Moxiechef (original poster) »

Great points of view from you guys.

From thinking about what you all have said, I'm leaning towards the 1#er. Controlling a 500g roast on a 2.5k roaster just seems like it's going to add a layer of difficulty on top of the daunting task of learning to roast.

The 1#er will be big enough to do a farmers market stand this summer and that will give me lots of practice cranking out 15 batches a week for three or four months. And if it's something we enjoy, find a few accounts plus our restaurants and then sell the 1#er and buy a 5 or 10k machine. Or maybe keep it as the sample roaster it is intended to be and add a large batch roaster to the arsenal.

What really turned my mind was the key to learning to roast is to roast........a lot. And the smaller roaster is designed and built to crank out small batches.

User avatar
drgary
Team HB
Posts: 14348
Joined: 14 years ago

#10: Post by drgary »

Jonathan, I like your thinking about roasting a lot. In a way the smaller roaster choice seems to force that practice and should move you up the learning curve faster.
Gary
LMWDP#308

What I WOULD do for a good cup of coffee!

Post Reply