When roasting large batches I've found that the Bullet's cooling tray can take up to 6-8 minutes to bring beans to room temp. Does anyone know of some standalone cooling trays that would be appropriate for ~700-800 grams? Most that I can find on alibaba/aliexpress are much too large.

A large colander and box fan is an old home roasting trick.

I found a (discontinued) StirChef for less than $5 at a thrift store which I modified to fit and added to the Bullet's cooling tray.



My batch sizes are normally around 600 grams but it does well at cooling the coffee. You have to watch out for the plastic stir vanes melting, though. Maybe you could also beef up the fan in the included cooling tray and add an external power supply to unlink it from the roaster.

EddyQ wrote:Recently, John Plato over at FB Aillio Bullet R1 User Group reviewed a Taiwan bean cooler for use with the Bullet.
Below is a link to the unit. He said it wasn't cheap at $600, but very well built and for him it was worth it.
http://www.youtube.com/watch?feature=yo ... th1U-6AL34

$600 is far too much, I was hoping around ~$100.

cannonfodder wrote:A large colander and box fan is an old home roasting trick.

I've made a couple DIY cooling units with laser cut acrylic, wire baskets from thrift store kitchen departments, and computer fans... I've been splitting the beans between my bullet cooler and one of my homemade ones recently. I'd like to get something more professional looking though, ideally with a filtration system so I don't blow smoke everywhere and have chaff flying out.

yakster wrote:I found a (discontinued) StirChef for less than $5 at a thrift store which I modified to fit and added to the Bullet's cooling tray.



My batch sizes are normally around 600 grams but it does well at cooling the coffee. You have to watch out for the plastic stir vanes melting, though. Maybe you could also beef up the fan in the included cooling tray and add an external power supply to unlink it from the roaster.

I've been stirring manually, and tried out a hacked together a mechanical one with a DC motor the other day. After trying out various speeds and vane shapes I don't think stirring is enough. Stirring is definitely helpful (you'd ruin your roast at 720 grams with the Bullet cooler and no stirring), but it's no substitute for more airflow. Any stirring speed sufficient to create more airflow and hit my timing targets (room temp @ 3-4 minutes) throws beans across the room. Ask me how I know this.

Another reason I don't want to just keep stirring is I have fundamental problems with the Bullet's cooler. I'm still a huge fan of the roaster itself, but the cooler was just poorly designed. The plastic case traps and retains heat, especially at the bottom. They should have considered a way they could integrate a metal heatsink at the least, or used aluminum in the casing. The fan's placement works well aesthetically and organizationally, but causes uneven air flow across the bowl (another reason stirring is so neccessary). The bowl is narrower and deeper than it should be, ideally the bowl would be 4-6 inches larger in diameter and much less deep, with more room for airflow within the case itself. I think they tried to optimize for a sweet spot so small amounts could be cooled efficiently but think they just got it wrong. The fan is also axial, instead of centrifugal (which is what's used in most cooling applications). I might look into 3D printing a centrifugal fan adapter for the Bullet, as that would make integration with my venting system easier as well.

I made a system very similar to Christian (Lambretta58) that I used with my Behmor. Worked great, I should try it with larger batches. Just have to watch to make sure you don't melt your shop vac hose or motor with the heat.

I did the old colander-in-a-bucket-with-the-shop-vac trick for awhile but I got tired of always needing the shop vac to cool my beans and it was slightly awkward and not very user friendly so I decided to come up with something better. People have done this before so I'm not taking full credit for this one but here's my version:

Find a discarded bathroom fan that still works. Not sure what the CFM of this one is, but any will most likely do. You aren't moving large volumes of air through those beans. I happened to be doing a bathroom reno and saved the old noisy one for this purpose.

Find yourself a nice colander with lots of holes. You can see how good the one is that I found. If you can't find one, find any, and as long as the holes it does have are small enough, you can drill a bunch more with a small drill bit for more air flow. That's what I ended up doing for the shop vac cooler until I found this one.

Find a piece of ducting to transition from the colander to the fan. You'll want it to be the right size. Too big and the air will flow around the beans, rather than through them due to the annular space that gets created if the "bean level" doesn't fill up to where the duct meets the colander. Too small and you won't be cooling all the beans efficiently. Something to keep in mind. Mine is a 3-4" transition.

You'll have to cut a small hole to allow the fan motor cord to go through or the duct won't sit flush on the fan housing. At this point, I tack welded the duct to the fan housing and used a liberal, very liberal, amount of silicone to fill the gaps. If you don't have access to a welder, I think you could get away with just silicone. I also tack welded the colander to the duct. But again if you don't have access to a welder, duck tape will work well to secure the colander to the duct. I used this method with good results with the shop vac cooler; just make sure you use small strips and don't try to go around it all at once.

Use an old lamp switch for the power cord for that extra wow factor and all of a sudden you're cooling beans like a son of a gun... On the cheap.

This thing makes a pound of hot beans cool to the touch in under 30 seconds in summer! Surely it would do 700-800g.

Price with discarded fan: >$20.

cannonfodder wrote:A large colander and box fan is an old home roasting trick.

+1
Air circulator and big colander will bring it to room temp in under 90 seconds. Price--well under $100 dollars. I kinda consider mine 'free.'

Lambretta58 wrote:I use a 5 gal bucket with lid, colander for steaming from a stock pot and a shop vac.

Cut out the lid so that the colander fits into but does not fall thru.

Cut a hole big enough so that the suction nozzle/hose from shop vac fits in.

Dump beans into colander, place in bucket, and turn on vac. Sometimes I stir them with my hand in a glove. Could stir with wooden spoon if need to.

Cools beans in no time.

Most I roast is a pound at a time. Don't see why it won't work for 600 grams.

Same here.
Since I have a shopvac, all I needed was a 5 gallon bucket with lid and a metal mixing bowl
Use hammer and a nail and a block of wood to punch holes in the metal mixing bowl bottom. Grind the sharp points protruding on the bottom side off with a grinder.

Goal was to not have any holes above the level of the beans and be sucking air that wasn't going through the beans.

And use a little plastic food cover tray that just fits into the metal Bowl, with a hose in the top of it to vacuum the beans into the cooling chamber. Then remove.

I think I spent about $30 for everything since already had the shop vac

Takes me maybe 10 seconds to vacuum the beans into the cooling chamber.
And immediately I can stir them all by hand with my bare hand. Time to cool depends on ambient but it's pretty quick