Zach & Dani’s Home Coffee Roaster (R.I.P)

The Zach & Dani’s Home Coffee Roaster (R.I.P)

The Zach & Dani’s Coffee Roaster is now known as the Nesco Home Coffee Roaster. Zach and Dani’s was a proprietary name for the machine, but Nesco was the manufacturer all along. Z & D, a company owned by the same people who brought your Orange Glo cleaner (!) decided to get out of the home coffee roasting racket.

Please go to our Nesco Home Coffee Roaster Page to read about, or possibly purchase, one of these machines!

Our Extended Review of the New Zach & Dani’s Home Coffee Roaster:

We are keeping this review online, but it is similar to the review for the current model of the machine that we sell, called the Nesco Home Coffee Roaster.

My first impression is that this large machine is unique among roasters and probably cost the Zach and Dani’s people a lot to develop and to build! It has two fans driven off the same motor, a belt-pulley system to drive the cast metal auger that agitates the coffee, and a sort of catalytic converter to help reduce smoke emissions while roasting. The latter is very effective (granted that smoke released over a long roast cycle – 20 minutes – like the Z&D is going to be less noticeable than a short 6 minute air roast). The converter includes a small heating element and a honeycombed ceramic piece that helps burn off smoke. The result is that a 4 oz. Zach and Dani’s roast has less smoke than the smallest capacity air popper roast.

The auger spins very fast and agitates the coffee very thoroughly during the roast cycle. There is very little airflow through the roast chamber during the roast cycle (and not much during the cooling either) so there is a lot of chaff mixed in with the coffee while roasting. Even the smallest pieces of chaff do not leave the roast chamber for the chaff collector. While this may not look good, it really doesn’t hurt the quality of the roast at all. Overall the chaff collection is poor and I would recommend, as with the Alpenrost) that you have a small Shop Vac handy. You can actually suck the chaff right out of the coffee if you don’t hold the Shop Vac nozzle too close, or you can dump the roast into a Stainless Steel mesh colander after the cooling cycle is complete, and shake out the chaff. You will want to get the roasted coffee out of the roast chamber as soon as the machine stops, because the slight air flow does not completely cool the coffee. I measured the beans at 130 degrees after the Z&D cooling cycle. This is not too bad, but what you really want is rapid cooling (best accomplished by massive cool air flow) in the first minute after the roast cycle terminates. Otherwise, the coffee continues to roast well into the cooling cycle, and indeed you need to learn to stop the roast early to take into account the additional roasting that will occur when the heating element is off.

This roaster is actually in the middle of a roast cycle … you can just make out the auger in the glass roast chamber. This is not a hot air roaster -it is a mechanically stirred roaster.

The roast controls are, like an Alpenrost, a bit lacking in that you can only set the roast time, then hit the Roast button. I keep hoping for a roaster with roast curve controls to truly allow custom roasting (the next generation Precision due out in May 2003 boasts this). But I think appliance manufacturers, trying to simplify machines, avoid customer confusion, and limit liability, are uninspired to build more user-programmable controls into machines. With the Zach and Dani’s, you simply choose the time you want to roast (default is 20, max is 30) and hit the roast button. But what I think is a nice improvement over the Alp is that the roast setting actually does correlate to time, and counts down as the roast progresses: a setting of 26 is a 26 minute roast+cool cycle (cooling is 5 minutes.) Roast batch size is optimally 4 oz. I was able to get an adequately dark roast off a 121.2 volt outlet with 4 oz of coffee, and not with 5 oz. You can also add up to 5 minutes to the roast while its in progress by using the UP arrow, meaning the max roast time is 35 minutes. To roast darker you can reduce the amount of coffee in the batch too (same as the Alpenrost, but opposite of the air roasters, where you get a darker roast by increasing the amount of coffee.)

This Simple roast controls .. the recall button just takes you back to the setting for your last roast. The default is “20”, which even with 121 volts would not produce a City roast. 24 is a good start setting with 4 oz. of coffee.

The roaster is really easy to use except for the chaff collector seal at the top of the unit. You need to pay attention to getting this properly seated or chaff will leak out and the roast heat will be lost. The best way is to push the chaff collector in the top and work your little finger around the seal to seat it, then seat the entire top onto the roast chamber and base.

Looking at the roast chamber from the side as the roaster is somewhat near first crack (the cracks are too quiet to hear.) The chaff doesn’t look good, but it does not impair roast quality. There’s so much chaff stuck to the sides you can’t see the auger in this picture

Looking down into the glass roast chamber after the roast is finished … you can see the chaff is everywhere! This is why you’ll want a Shop Vac around.

The even roast color from the Z&D (this is a Java Blawan)

Underside of the top end. You remove this after each roast to clean the chaff collector and screen -as with all roasters, residual chaff will affect the next roast. Update 8/04 – the lid is now hinged to the roaster body, which makes it a lot more convenient!

You need to seat the chaff collector in the top end carefully before each roast. Much of the chaff is mixed in with the coffee after the roast finishes. A Shop Vac is best to clean this.

under the chaff collector is a very fine screen that clogs with chaff particles between each roast. Over time, this might clog and reduce air flow.
Overall, the roaster works well for someone who hasn’t been exposed to roasting before. It seems durable and of high quality, and probably low maintenance too. (One topic is the belt that drives the auger; A friend thinks this belt is very well insulated and will last quite a while: I think its going to cause trouble and need replacing or adjustment fairly often. There is a belt drive tensioner in the base of the machine and this needs to be engaged to drive the auger better -the machine may squeal a bit with it engaged but this is better than having the auger jam during the roast.) We haven’t heard of people receiving defective units or having failures after a few uses, but in the long term the roaster is too new to know how it will hold up. The component parts certainly seem to be high quality.
One warning, the exposed base metal is really hot! The temperature where its marked “Hot” gets up above 170 and right next to the glass it gets up to 213!

The roast color is exceptionally even (this is nice visually but does not necessarily relate to cup quality), and bean development early in the roast is uniform. (Early development has been a problem with other roasters, like the Freshroast). The later fact is more critical to good cup quality: the uneven development early in the FreshRoast batches concerns me more than the final roast color. The roast color of the exterior of the bean and the Agtron Number assigned to the grind are closer to a match (2-5 points) than they are in an air roaster (which can differ by 8 or so). The First Crack and the Second Crack are nearly impossible to hear, not because of machine noise, but because of this “low temperature-low air” roast technique the machine employs. More on that when we talk about roast quality….

The main concern that comes up with the Zach and Dani’s is the cup quality, especially of the darker roasts. For someone that hasn’t roasted before, the machine will offer a great improvement over store-bought coffee and will probably match some micro-roasted or gourmet chain coffee too. But we have gone through a considerable amount of coffee and have noticed a dullness in the cup. I think the cause might be the inadequate cooling (not the temperature after the 5 minute cycle, but the fact that the low air flow is inadequate to drop the coffee temperature in the first minute or two). Although I removed the coffee from the roast chamber immediately after the cooling cycle each time, the ideal thing to do is to remove it as soon as the roast cycle ends, dump it in an S/S colander and draw high speed fan air through it.

The second possible cause is a function of the long roast time. Roasts of 19-25 minutes are a bit longer than most commercial roasts. In my Diedrich 12K shop roaster, I started out with roast times recommended by Diedrich of around 16 – 18 minutes for City-Full City, and 19-21 for dark roasts. But total length of time is only part of the effect. In drum roasters, the roast finishes fast … it passes promptly from the exothermic first crack into endothermy (the quiet time between cracks) and back into the exothermy of the physical fracturing of the coffee, also called second crack. A drum roaster operator usually struggles to slow this down a bit, partly for control so an exact degree-of-roast can be determined, partly because of roast profile preferences. If you are headed toward 2nd crack on a bid drum roaster with a lot of flame on and the air closed, watch out. One popular technique is to shut down heat and close down dampers to coast into 2nd crack, drawing out the duration of the crack a bit.

But the incredibly slow finish of the Zach and Dani’s roaster is off the traditional “slow finish” scale. It’s incredibly slow, and what amazes me is that it isn’t stalling the roast completely after 1st crack (maybe it is … I can’t put a thermocouple probe into this model I am testing because it’s not mine!) With a first crack finishing 12.5 minutes into the roast and a second crack starting at 19.5 minutes, the lull between them is exceptionally long (note; this was with a smaller batch size, their “french roast” batch size): this does give you a lot of time to determine the “degree of roast” you want but the cost might be the roast quality. This long roast time starting with the first exothermic reaction is unlike any roaster I have used, professional or home roaster. If I could tweak this thing, it would be a burner control to accelerate the roast as the coffee is on the verge of First Crack to prevent a roast stall, then back off a little, then back off a little more as it reaches my target roast temperature. But I think the Z&D is really aimed at someone who isn’t going to worry about these things, or look inside the roaster, and hasn’t heard of roasting before so they don’t have a basis for comparison. My sense is that this company has a lot of money put into this machine, and might change the roast profile on future versions.

Someone told me this is the roaster they would give their grandmother, and after using this a while, I would think so, or at least for your hobby-addicted uncle. 🙂 It does work well and the mechanisms inspire confidence. For someone who wants to open it up and play with the heat coil, and find a good place to insert a temperature probe, the Zach and Dani’s offers some great possibilities. After all, this is mechanically a unique roaster. I think overall frustration with the limited selection of home roasters out there, and bad experiences people have had with what has been available makes any new roaster a welcome addition. But like all home roasters, it’s a mixture of strengths and weaknesses for me. The Z&D medium roast of the Java in the reviewbelow sums up both.

A cupping note: I have found that an unexpected strength of this machine is lighter roasts. Most home roasters (and popcorn poppers) pass rapidly from first to second crack without a significant pause, The Zach and Dani’s has this long pause between cracks and the hidden benefit of this is there is a lot of time for you, the roaster-operator to ponder the exact time you want to stop the roast. The roasts in these City to Full City stages, before 2nd crack, are very even, and the coffee has not been in the roaster (baking) for as long as the very long dark roasts in this machine. So we are finding some nice cup results in these medium City roasts, and they are easier than other roasters to pinpoint. -Tom 2/8

Cupping Comparison: Zach and Dani’s Roaster; Hearthware Precision; Hearthware Gourmet

We chose a coffee for this test that I felt would be strongly suited to the Zach and Dani’s roaster; longer roasts might mute dynamic bright notes and acidity in coffee but will develop a heavier body in the cup. Java is all about body, but has interesting other flavors that emerge, as you will see in the HWP notes below. The logistics of including all the roasters, the Alpenrost, the FreshRoast and the Caffe Rosto, in this test were just too much for me. From all the other roasts we have done in the Z& D, I am getting a good feel for its strengths (mostly its innovative design, quietness and lack of smoke, lighter roasts) and its limits (dullness in the heavier roast’s cup quality). I wanted to get a general feel for the air roast versus the Zach and Dani’s mechanically agitated roast, and sort of formalize the comparisons forming in my mind between these roasters.

Zach and Dani’s Zach and Dani’s
Coffee: Java Blawan Roast: City: Medium (Agtron 55) Coffee: Java Blawan Roast: Full City+ , Medium Dark (Agtron 45)
Dry Fragrance (1-5) 3 Dry Fragrance (1-5) 3.5
Wet Aroma (1-5) 2.5 Wet Aroma (1-5) 3
Brightness – Acidity (1-10) 8 Brightness – Acidity (1-10) 7
Flavor – Depth (1-10) 7.5 Flavor – Depth (1-10) 8
Body – Movement (1-5) 3.5 Body – Movement (1-5) 4.5
Finish – Aftertaste (1-10) 7.5 Finish – Aftertaste (1-10) 8
Cupper’s Correction (1-5) 0 Cupper’s Correction (1-5) 0
add 50 50 add 50 50
Score (Max. 100) 82 Score (Max. 100) 84
Notes: This was probably the poorest roast in the cupping because I couldn’t find much to like about it side-by-side with the other cups. I could sense diminished cup quality in almost every category, and was a little surprised. I am not saying this was a bad cup, but it had noticeably less body than the other Agtron 55 roasts (the HWG was Agtron 60), much less aroma, and was dull overall, without chocolate bittersweet, without fruit, without spice. This was a 4 oz batch roasted for 18 minutes with a 5 minute cool cycle = roaster setting 23. I thought the Blawan would play to the Z&D’s strong suit (body) but maybe I was wrong, since lighter roasts of bright coffees turned out quite nice. Notes: The Agtron 45 Z&D roast had good body, as I had hoped for from such a long roast. While its longer roast time than the Diedrich 12K shop roaster, I expected to see something similar emerge in the cup. This roast probably had a tad more body than any other roast on the table but it wasn’t a dramatic difference. What I did notice was a dullness in the roast taste compared to the other Agtron 45 roasts. The sharp bittersweets were not there. It tasted like a coffee that had sat around a while, yet it was roasted just before the HWP batches and rested the same 24 hours. In a way, this reminds me of what I would get at a local roast shop from coffee roasted sometime that week: a fresh cup in that context, but a dull cup next to the other roasts. Like the Agtron 55 Z&D, this was a little dulled next to others, and without subtlety in the cup, but had more positive flavors because of the heavier roast tastes. No fruitiness in the cup. This was a 4 oz batch roasted for 21 minutes with a 5 minute cool cycle = roaster setting 26.
Hearthware Precision Hearthware Precision
Coffee: Java Blawan Roast: City: Medium (Agtron 55) Coffee: Java Blawan Roast: Full City+ , Medium Dark (Agtron 45)
Dry Fragrance (1-5) 3 Dry Fragrance (1-5) 3
Wet Aroma (1-5) 3 Wet Aroma (1-5) 3
Brightness – Acidity (1-10) 8 Brightness – Acidity (1-10) 8
Flavor – Depth (1-10) 8.6 Flavor – Depth (1-10) 9
Body – Movement (1-5) 4.2 Body – Movement (1-5) 4
Finish – Aftertaste (1-10) 8 Finish – Aftertaste (1-10) 9
Cupper’s Correction (1-5) 1 Cupper’s Correction (1-5) 0
add 50 50 add 50 50
Score (Max. 100) 85.8 Score (Max. 100) 86
Notes: This roast had good aromatics but was not very exciting initially, lacking brightness in the nose of the lighter HWG roast and the bittersweet of the Agtron 45 roasts. But as the cup cooled a remarkable balance between flavors emerged (mild chocolate bittersweet with coffee cherry fruitiness) and there was a subtle cinnamon in the finish that no other cup had -this score doesn’t reflect the fact that this was ultimately the most complex cup with the most “origin character” in the cupping -hence a +1 cuppers correction for complexity and subtlety. This batch was 3.25 oz on HWP setting about 5.8 Notes: The Agtron 45 HWP roast was the winner for roast taste. It had a sharp, tangy chocolate-bittersweet with much more aroma from the roasty flavors than any other roast. I didn’t add 1 for a cupper’s correction because the scores in the aftertaste already express the very long, alkaloidy chocolate flavors that persisted until I rinsed with water… The body seemed a little lighter than the Z&D roaster at the same setting, but very slightly so. This batch was 3.25 oz on HWP setting 6.5
Hearthware Gourmet Hearthware Gourmet
Coffee: Java Blawan Roast: City: Medium-Light (Agtron 60) Coffee: Java Blawan Roast: Full City+ , Medium Dark (Agtron 45)
Dry Fragrance (1-5) 3 Dry Fragrance (1-5) 3
Wet Aroma (1-5) 3.5 Wet Aroma (1-5) 3
Brightness – Acidity (1-10) 8.5 Brightness – Acidity (1-10) 8
Flavor – Depth (1-10) 8 Flavor – Depth (1-10) 8.5
Body – Movement (1-5) 3 Body – Movement (1-5) 3.5
Finish – Aftertaste (1-10) 8 Finish – Aftertaste (1-10) 8.5
Cupper’s Correction (1-5) 0 Cupper’s Correction (1-5) 0
add 50 50 add 50 50
Score (Max. 100) 84 Score (Max. 100) 84.5
Notes: This was a bit underroasted for a Java (Agtron 60 compared to 55 in the other roasters) and had less body and a little bit of an underdeveloped roast taste. It was too late to re-roast it to a 55 darkness because than it wouldn’t have rested the same amount of time as the other cups. Nonetheless, there was great aromatic fruitiness in this cup, very much a coffee flower-coffee cherry aroma/flavor, and it made it a fun cup to have next to the others. But it scores lower in a few categories because the optimal cup for a Java was not really reached in this roast. This was 1/2 cup roasted at HWg setting 6 Notes: The Agtron 55 roast in the HWG is lighter in body when you cup it right next to the Z&D, and that’s no surprise since this is less than a 6 minute roast cycle next to a 21 minute roast. But the roast flavors are really nice and like the cup from the HWP at the same degree of roast, the chocolatey-roasty notes are distinctly tangy and aromatic. The aftertaste is correspondingly longer too. This was 1/2 cup roasted at HWG setting 6.8 or so.


Recommended Coffees for the Zach & Dani’s Roaster

We roasted quite a few coffees on this machine… initially thinking that the only the strong suit of this roaster is low-toned coffee with a lot of body. I found later that I could pinpoint the lighter City roasts very easily due to the long pause between 1st and 2nd crack. And these roasts came out very evenly. We have had some very nice cups from the lighter roasts, including the Yirgacheffe, Sidamo, Guatemala Arte de Maya, El Injerto, and La Minita

To serve to the Z&D’s strengths, you want to explore the Indonesians. If the idea of an earthy, pungent, deep coffee with low acidity appeals to you, start with the dry-processed Sulawesi, and the premium Sumatra Iskandar Triple Pick. If you want these qualities without the earthiness, try the wet-processed Indoneisans from JavaTimor or Papua New Guinea.

You can do straight roasts of high-toned coffees, or blend them. For a bright, fruity cup with a bit of natural-process character, thy the Ethiopian Harar, or the Yemeni coffees. For a cleaner cup character, try the wet-process Ethiopian Yirgacheffe, or the Kenya Auction Lot coffees. You are going to be loosing the high-end of the cup roasting these coffees, but they still make a nice cup. You can blend the Harar/Yemen with the Sulawesi for a balanced, pungent Mokha-Java, or you can add the brightness of the Kenya/Yirgacheffe to a clean Indonesian like the Java or Timor.

The Central American coffees make fairly nice roasts … and of these I would recommend the Guatemalans and Nicaraguas over others like Costa Rican. This is based on the cup results I had with the Z&D roasts of the La Minita. The Colombians hold up well, and since we have some exceptional ones to offer it is a shame to pass them up. The Brazils will work well as a blender with this roaster, not as a straight roast.

Coffees that are entirely about their subtle nature will not do well in the Zach & Dani’s roaster. It will be best to roast on the dark side for milder coffees so you can develop the “roast tastes” if the “origin flavors” in the cup become dulled or lost. (In our Java Blawan test above, note that the darker roast scores much better than the medium roast).