# Simplicity for the home roaster



## CoffeeMagic

I've just been running some preliminary tests on the Baby Roaster FZ-RR-700, by Coffee-Tech Eng. What a beautifully simplistic piece of kit. Talk about bean to cup, this was green bean to cup in less than 15min. Crazy, but true.

There is a blog post on the first roasts with a manual unit, prior to the tests with the motorized version.

I wanted to thoroughly test these from the point of view of sales, via my website, and as a tool for use in my home roasting courses that are currently in the planning stages. Since it will be all about the principles, this little beauty seems to tick the boxes.

My interest in this particular unit was sparked when I read a very lengthy thread about it on my other forum (coffeesnobs). This just begged to be put through its paces in the CoffeeMagic Test Lab









It will also make a fantastic sample roaster for trialling blends and roast levels.


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## oldman

Sounds interesting. Estimated pricing?


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## CoffeeMagic

Probably around 150 for manual. The motorised version will be a bit more.


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## MikeHag

Capacity? *Edit* Sorry - have read your blog post now... 200g. Bigger than I expected!

Test roasters really intrigue me. I struggle with how the roast profile of a smaller bean mass can be scaled up and still deliver the same results. Not that I dont think it's possible... I just want to understand more about it!


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## CoffeeMagic

In most cases it is not so much about creating a roast profile as tasting the result. A sample roaster is just that - a taste sampler. Do I need to roast lighter or darker to get that sweet spot? What proportions do I need in a specific blend?

On the production roaster you will already know roughly what profile to use, partly determined by the bean (varietal, location, etc.) and the roast level. Unless the sample roaster uses the same principles to roast the small batch, it won't translate to a production batch roaster.

The majority of home roasters fall into the 'fluid bed' category with electric heat source. This one is closer to the type of sample roaster used in production environments, since it uses a gas flame (drum).


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## MikeHag

CoffeeMagic said:


> In most cases it is not so much about creating a roast profile as tasting the result. A sample roaster is just that - a taste sampler. Do I need to roast lighter or darker to get that sweet spot? What proportions do I need in a specific blend?


Well you see, that's just my point. As someone new to roasting I've been doing my reading, and what I'm learning is that it's not just about achieving a particular colour (as you know). The same beans, roasted to the same colour, in the same roaster, will taste very different if they have a different roast profile e.g. was it a slow build up of temperature, perhaps being held at a certain point for 3 minutes before increasing the temperature again... or was the roaster temperature just set to maximum and once the bean mass temperature reached the target then it was held there until it reached the right colour?

What particularly baffles me is that a small (e.g. 200g) bean mass won't (I think) be able to follow the same profile as a large (e.g. 5kg) bean mass, simply because the larger bean mass has more thermal momentum.

Anyway, if what you're saying is that test roasters are basically just bean browners then that's fine as long as I know that's their limitation







Please forgive my noobiness about such things.


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## wastedhours

I've read that a lot of commercial sample roasters can get to second crack in about 8 minutes (and that people use them that way), so I think being able to build a production profile on such a machine would be difficult.

Edit: obviously huge-batch commercial machines also roast this quickly - but most that I've seen up to 90kg are in the 16-22 minute ball park.


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## CoffeeMagic

MikeHag said:


> Well you see, that's just my point. As someone new to roasting I've been doing my reading, and what I'm learning is that it's not just about achieving a particular colour (as you know). The same beans, roasted to the same colour, in the same roaster, will taste very different if they have a different roast profile e.g. was it a slow build up of temperature, perhaps being held at a certain point for 3 minutes before increasing the temperature again... or was the roaster temperature just set to maximum and once the bean mass temperature reached the target then it was held there until it reached the right colour?
> 
> What particularly baffles me is that a small (e.g. 200g) bean mass won't (I think) be able to follow the same profile as a large (e.g. 5kg) bean mass, simply because the larger bean mass has more thermal momentum.
> 
> Anyway, if what you're saying is that test roasters are basically just bean browners then that's fine as long as I know that's their limitation
> 
> 
> 
> 
> 
> 
> 
> Please forgive my noobiness about such things.


That's not what I am saying. I think the first big thing that needs to be straightened out is that it is not a precision process. You can't just put numbers to these things and have a nice table like you use for brewing. However, in saying that, you have to start somewhere. There are far too many variables and fewer controls for it to be precise. Why does the same wine taste different from year to year? Why do 2 steaks of the same weight and size and cooked using the same method taste slightly different?

Yes, some roasters do use colour and hence the use of Agtron scale test equipment. Some by profile and colour, others "gut feel". With a sample roaster its main use will be for cupping. It may also be used to experiment with the heat requirements for a particular bean - e.g. a Giesha needs a different heat profile to a typica. You certainly wouldn't roast 15kg of beans just to discover that the blend doesn't deliver the characteristics that you wanted.

With regard to scaling, there is no reason why 200g in a small drum using conduction cannot scale to a 15kg drum that effectively uses the same principles of conduction. In the larger drum there would also be the effects of convection and radiation.

Forgive me for saying it, but I think you need to be less fanatical about numbers and facts. It is more of an art than a science, in my opinion







.


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## MikeHag

No, that's fine, I don't mind you saying it







I am learning. It's just that what I hear different things from different people. A lot of guys seem to use software linked to probes to monitor and chart their roasts, and that approach does appeal to me. I guess it's like all things coffee... no single right or wrong way... which is always slightly puzzling for we beginners.


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## CoffeeMagic

That's what I mean. You will always hear different things from different people, because it isn't a precise science. That's where the art comes in







. If it was precise then there would probably be a roaster that everyone used where you just need to enter a few parameters and it does it all automagically.

Don't get too swept up in temperatures either, as it makes a difference where you measure it. The consistency comes from using the same probe in the same place.

I think the reason it appears puzzling is because there are no hard and fast rules or definition of what is right. "Feel the force, Luke"







I'm just wondering how you manage to get all your cakes to turn out the same?


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## MikeHag

What, these?


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## CoffeeMagic

See what I mean







Did you use an oven thermometer?

Temperature measurement is predominantly used as a way of recording (or logging) a roast rather than controlling it. It's going to tell you if the ramp up is too steep or shallow, which can make the difference between roasting and baking and give you an idea of when you can expect an event so that you can adjust the heat or air inputs.


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## MikeHag

I forgot to set the timer and forgot about 'em







The oven where we're living at the moment is shite anyway. Roll on Thursday ... NEW HOME!!

Yeah, that's my understanding of roast logging. I think measurement would help (me) with repeatability and tweaking the profile of the next roast by following the previous one up to the 'tweakpoint'. That's the science that appeals to me over the art approach, although I completely agree that repetition and familiarity on the same equipment would also deliver repeatability in an arguably more artisan and romantic fashion than digital dataloggers.

Thanks for explaining things to me. Much appreciated.


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