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Fresh roasted Almonds anyone?

Posted: Wed 07 Oct, 2020 2:21 am
by DMC314159
While enjoying lingering aroma of a coffee roast recently, I had what you might call a heretical thought:
"I wonder how good the Nano 7 would be at dry roasting Almonds?"
So, after a bit of research and playing with profiles, I can safely say that the Nano is brilliant for roasting almonds.
Fresh Roasted Almonds.jpg
Roasted Almonds
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As you can see they look great, and I promise that they taste fantastic too.
I have taken to not having the range hood's fan on during the roast as my wife likes the smell of the roast. Think gently baking bread with a pleasant touch of nuttiness.

A critical question you may be asking is:
"Does any of this hurt the Nano or the coffee beans it roasts?"
Having done about 10 almond roasts mixed in with 20 coffee roasts, and having talked with Chris Hilder, I believe the answer is a simple No.
Chris and his team thought the risk of damage is low, with the three biggest risks being:
  1. A nut getting stuck in the internals of the Nano after squeezing through an air vent from the roasting chamber.
  2. The air being completely blocked off causing the heater to trip it's safety fuse.
  3. Nut residue in the roast chamber might affect the flavour of the coffee, especially if the nuts get burnt.
Based on the roasts I have done:
  1. Any thing smaller than a coffee bean like chaff or tiny chips of almond tends to be blown out the top, particularly as the fan is being run at 100% to keep the nuts dancing.
  2. On every occasion the almonds stop dancing there has been plenty of air blowing through. The nuts seem to have grouped together and left holes for the air to blow past the groups.
  3. None of my almond roasts have burnt or even spotted any nuts. This includes the first few roasts that shutdown early a couple of times due to heating to fast warnings. Also, very little oil passed from the almonds to the roasting chamber as the nuts tend to keep their skins on. To date, the flavour of the coffee coming out of the Nano continues to be great, and to the best of my ability to tell, has not changed. I suppose I might be up for a deep clean of the roasting chamber in 5 years time, but it will be worth it if this coffee and these nuts are anything to go by.
I have worked my way to the attached two stage profile using information from the Almond Board of California at https://www.almonds.com/sites/default/f ... almond.pdf and conversation with Chris Hilder.

The plateau at 130 degrees C gives time for the nuts internal structure to settle during the Maillard reaction, and the 180 degree peak gives a nice mid range roasted taste and colour.
Almond roast log trace.jpg
Almond roast trace
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While the profile as it stands is reliably giving me great results, there are two areas I see for improvement.

First up, on occasion the nuts will stop dancing in the hot air.
This is easy to fix by gently jiggling the roaster to get the nuts moving again. Leave the char chimney off so you can see if the nuts are dancing isn't a problem because there is no char coming off the nuts. The problem is having to check the nuts ever 30 seconds or so through the whole nine minute roast. The fan is already at 100%, so we can't get more help there. Reducing the batch size so the nuts stay just below the probe might help keep the dance going, but what does that do to the temperature readings?

Secondly, It would be nice to get rid of the oscillation in the actual rate of temp rise curve.
This needs more tuning of the PID, but is pretty much a nice to have as the heating curve is following the profile reasonable closely, and most importantly the nuts are tasting fantastic.

I look forward to hearing your thoughts and experiences with roasting almonds,
and hopefully suggested improvements of the profile.

David

Re: Fresh roasted Almonds anyone?

Posted: Wed 07 Oct, 2020 10:43 am
by kaffelogic
Congratulations on a great piece of profile design. I think your PID tuning looks great. I wouldn't be concerned about reducing the batch size because the probe does not need to be among the nuts to control the roast - just try taking the batch size down until you reach the point where you don't have to stand over the roast.

Cashews and Hazel Nuts too

Posted: Sun 14 Feb, 2021 12:17 pm
by kaffelogic
After further experimentation with roasting nuts using David's profile, I have had great success with cashew and hazel nuts. I have made a change to allow the roast to be automatically stopped earlier, so the levels have been shifted down, but nothing else has changed. I have called the modified profile "Completely nuts" because it allows a range of different nuts to be roasted. I have tended to level 2.5 for cashews and hazels, and 3 or 3.5 for almonds.

As David has pointed out, the PID could be better tuned, but as the flavour of the nuts is already excellent I have not made the effort to do that. Here's a log of a hazel nut roast:
log0077.png
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Hazel nuts
Kaffelogic-roasted hazel nuts are divine. They do have skins so the chaff collector is needed. On the other hand you need to see what is going on so you can give the nuts a quick poke with a chopstick when they jam up. You don't need to be paranoid about this - they will sit jammed up and not circulating for quite some time without coming to any harm or starting to burn. Here's my hack for watching the nuts. It is a small glass pot lid. It does need to be small so that it balances easily and so that is not too heavy for the chaff collector (the mesh gets softer when it is hot). When you need to stir during the roast, lift the chaff collector off gently from its bottom part, poke the nuts, and lift the chaff collector gently back on again.
IMG_20210214_104121.jpg
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Cashews
These tend to lock together so continuous poking/stirring with a chopstick is called for, and of course no chaff collector is needed.