Probat vs. Diedrich

[6644hudson]

Odd, isn't it, to have a roaster with a name? But we didn't name it Lola; we bought it from Joel Edwards in Chicago, who had bought it from somebody else. It was named Lola when he acquired it and apparently there was a little tradition to name these roasters after women, for some reason. We call our espresso machine Linnea.

 

[wwcove]

Only buy a roaster with a double layer drum.

 

[imperialroasters]

I know this thread is several months old, but i thought I'd contribute some of my recent findings based on my own research on the Diedrich IR5 ($22k) and Probat P5 ($34K) - prices include all shipping costs and training offered by each company.

I was originally convinced that I wanted the Diedrich IR5,... partly because one of my favorite roasts comes from a company that uses one - mayflycoffee.com, and partly because the price was much more affordable. But as i researched the Probat P5, I began to question my decision. Here is what i found:

Diedrich:
- indirect, infrared heating which roasts the beans through convection style heating
- perforated drum
- 4 thermocouples and compatibility with Artisan software
- 3 roasts per hour (due partly to time required to come back to temp between roasts)
- optional roast automation software available

- cons:
- unable to efficiently roast at 100% capacity
- downtime between roasts
- competition claims that convection method of roasting produces a "less than uniform" roast

Probat p5:
- solid double walled insulated drum - providing a more uniform and consistent delivery of conduction heating
- uniform roast via conduction heating between the drum and from bean to bean
- 4 roasts per hour (since the insulated drum minimizes heat loss between roasts)
- 2 thermocouples (exhaust and bean/ambient) - compatible with artisan software
- can roast efficiently at 100% capacity
- it has been said that Probat roasters are well suited for slower, darker roasts
- roaster adjusts the roast through manipulation of the heat rather than manipulating the air flow within the drum

- cons:
- unable to roast effectively below 75% capacity because fewer beans means that the conductive heating between beans will take longer; in addition, roast profiles and times will be different than larger batches
- does not offer a automation option

I'm still considering both and haven't made a decision as of yet. Since i prefer light/medium, I would like to know whether the Probat excels at slow, light/medium roasts like it does for slow, dark roasts.

 

[sae]

@imperialroasters I wanted to clear up a few things
- The diedrichs do not have a perforated drum
- you can do back to back roasts on the diedrich no problem (there is no need to come back up to temperature between roasts, if anything you'll have to cool it down between roasts to get back to the charge temp you want)
- Roasting is very uniform.
- Diedrich roasters do use all 3 types of heating (convection, conduction and radiation) but open air atmospheric type roasters do have more convection roasting
- You can do 100% capacity but it depends on how much gas pressure you have and what type of roast you are trying to do
- The probat has a double walled drum so the heat of the burner doesn't hit the surface where the beans are. They claim this minimizes scorching but it would also increase the response time to conduction roasting (not saying this is good or bad, just different)
- Intersting what you say about slower darker roasts because most specialty coffee roasters buy a probat for it's ability to roast fast and light
- both the diedrich and the probat (and a US Roaster Corp, and an Ambex, and a Toper, etc) allow you to control the flame and the air going through the drum
You can't go wrong with either they are just a bit different in how they distribute the heat. You can achieve light and fruity all the way to dark and smokey on both roasters you just might have to approach how you do that slightly differently.

 

[wwcove]

Does anyone know what type of steel is used in each drum? Stainless steel? Or carbon steel?

 

[sae]

carbon steel for the diedrich (toper and ambex also?), stainless steel for the USRC (at least on the newer ones), cast iron for the Probats and Jopers

 

[Amhas]

Diedrich:
- indirect, infrared heating which roasts the beans through convection style heating
- perforated drum
- 4 thermocouples and compatibility with Artisan software
- 3 roasts per hour (due partly to time required to come back to temp between roasts)
- optional roast automation software available

- cons:
- unable to efficiently roast at 100% capacity
- downtime between roasts
- competition claims that convection method of roasting produces a "less than uniform" roast

Imperial roasters,
I have an IR1 that I have been using for just about 1 year now. Same design as the IR5 but just at a smaller scale and here's what I can tell you from experience. I have no experience with Probat but I expect it is a very high quality machine, just out of my price range.

I too was told you can't roast at 100% capacity (maybe 80%), but I can tell you now that I have all but debunked that theory. For the longest time I would run my roasts at no more than 80%. I'm now roasting at 95% capacity. I'd do 100% but 95% gives me 2 12oz bags with some remaining for cupping/sampling each batch. My experience here with full capacity is that consistency is the same or maybe even better; however, it does require that I have the gas at 100% open at times during the roast. Benefits are it holds heat better and seems to actual provide a less erratic temperature fluctuation.

As for roasts per hour. Well this comes down to experience. If you're new to roasting I can tell you that doing 3 per hour is all but impossible. I can tell you that bringing the system back up in temp is not the issue as most roasts will finish at or above your desired drop temperature (in my case I'm using around 375 - 380 degrees F). What is a challenge is getting the system down and then back up with a consistent temperature (not to missing if if you get distracted bagging or other details). I personally try to make sure that the ET and BT are consistent when starting the batch if they are different it can definitely impact the roast profile giving you very inconsistent results. I have 200+ batches of experience now and if I am lucky I can get around 2.5 batches done per hour. It does depend on the external temperature in the room where you're roasting and this doesn't include the 30 to 45 minutes of warm up time (you want the roaster to be a big heat sink so warm up time is very important for consistency on your first batch or two).
Note here I would die for a system that would come up to temperature and stay there but this process of getting the roaster to the proper drop temp is something that I find to be very tedious and annoying if you get distracted and miss your drop temp. :decaf:

Convection? I think you may have bit mislead or got a bit of bad info from their competition. I'm not here to sell you on either. As someone noted as well the drum on the IR systems are not perforated and heat from the IR burner is actually just under the drum so heat is directly applied (conduction) to the drum and there's there is a damper that allows you to control the air flow through the drum (convection). Air flow is necessary and all systems have some airflow (remove smoke and chaff to prevent fires) but some don't allow you to control it. My complaint if any here is that the IR1 only allows for 3 different airflow settings and I'd like to have infinite control over it.

My overall thoughts are that these machines are all very basic (I have only played with 3 different machines and never a Probat). My understanding is that the automated software is not great. It is my understanding that it is kind of like your cruise control on your car. It works great if every single factor is the same but throw in some variation and when it attempts to adjust for that (kind of like cruise control does when coming up over a hill) it can over react where as a human can predict this and slowly back off. Maybe this is better now but for I think it is $14k for the IR systems I can't see using it. However, if it could bring a system up to and maintain an even drop temp (using the ET and BT) then I'd say there's some production value in that, but it would still take a lot of time to pay off that investment.

Feel free to contact me if you have any questions.

 

[sae]

On the diedrich you can have almost infinite air control. The air damper does have 3 detents but you can put the lever anywhere you want between these settings. If your damper doesn't stay there you can tighten it up so it does stay between settings.

 

[Amhas]

On the diedrich you can have almost infinite air control. The air damper does have 3 detents but you can put the lever anywhere you want between these settings. If your damper doesn't stay there you can tighten it up so it does stay between settings.

Interesting... I have to look into that. Obviously infinite only between 20% and 80% split between cooling bin and the roasting drum.