# Anfim grinder modifications to reduce retention



## Paul CS (Dec 2, 2017)

Hello everyone,

I've had my Anfim for over a year now (thank you coffeechap). I have learnt so much from you guys and producing espresso's that I'm really happy with. Many friends agree. My favourite beans are Monsoon Malabar from Monsoon Coffee Estates.

As my learning grows I've become focused on retention. Every few days I remove the top and using a brush and vacuum, give it a good clean. I guess there is 10g of coffee sitting in there. Every couple of weeks I take it into the garden and give it a good blast from a compressor. Very messy!

It's a bit of a faff. It's even got me thinking about a Niche Zero, but something tells me the great and good here might have a solution. I'm open to any modifications and as a Mechanical Engineer, have access to a machine shop so very happy to go for it!

For reference, below is a picture of my set up.

Looking forward to your views.

Thanks

Paul


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## Mrboots2u (May 10, 2013)

Lens hood mod?

There is a difference between retention and exchange - copyright @DavecUK

So it sat 10 g in the grinder always there?

If you clean it out put 18g grind, how much comes out?

Do the same again how much comes out ?

Do you use a lens hood to blow out any grinds shot to shot in the shute?


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## Paul CS (Dec 2, 2017)

Ah...

Retention and exchange. Thing is, I grind on demand and if I am away for a day or so, there is old coffee in the grinder that will be pushed through (exchanged, yes?) with the new coffee. I want to avoid that.

Retention is the coffee that never comes out unless cleaned, yes?

I'm not sure about the Lens hood because I have tried an air blower which made a huge mess! And that did not seem like a thorough clean. I should be opened minded and try that - off to Amazon.

Tomorrow I will try feeding in coffee and measuring as you describe and will report back.

Thanks

Paul


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## ajohn (Sep 23, 2017)

I too use Monsoon Estates and the same bean and have weighed in on a Mazzer Mini. The lens hood mod is needed to minimise the retention on any conventional flat bur grinder.

You need some plastic tube that fits in place of the hopper. Perspex or acrylic. This isn't needed on some Mazzers. Then a rubber 3 stage folding lens hood to fit onto the plastic tube. Basic idea is beans are put into the tube, grinder ran until all of the beans are ground and then the rubber lens hood is compressed smartly to create a puff of air to blow the rest of the grinds out. Then brush out the exit from the grind chamber. As per this






Some one has added a clump crusher / anti static flap to that mazzer.

What I found in practice is that it's a little more complicated than the video shows but it will depend on how accurate you want to be. I found it to be best to do what the video shows then spin the grinder up again, puff and then use the brush again. This is likely to be even more important with the bean you are using.

Net effect is that the grinder quickly settles down to what goes in comes out to within 0.1g. When I looked which was following every new bean order the only odd retention I saw was a small spike of grinds on the part that sweeps them out or nothing at all. Most of the permanent retention is well and truly buried. Thin film around the grind chamber so carry over if you change beans will not be that high. This has cropped up on the infamous Sage grinder in the past. Permanent retention that isn't swept out when weighing in is relatively high. Probably a gram plus but it's well compacted. So if the bean is changed just the surface shifts which is large on Sage as they use a plastic grinds chamber so need it. Even when switching beans with a very distinctive taste such as a flavoured bean to something normal just 20g through gets rid of any carry over. It's hard to see how any flat burr grinder can be as bad as that - but







maybe. What I did on that one was just drink what came out. Usually just first in this case 10g dose had any noticeable carry over. Better to put up with that rather than cleaning and waiting for the compaction to build up again.

The other mod that is worth doing along with the lens hood and tube is a weight of some sort over the beans. Just a piece of metal with an easy fit. It stops the beans from bouncing around and breaking up too much. It also keeps the bits in place rather than spraying the inside of the lens hood with them. If a cover of some sort isn't used they can go all over the place. One problem. Best to add another use of the brush. After the first spin up of the grinder lift the weight and brush any bits onto the burs. Replace and carry on as before. It also on a mazzer helps to lift the weight a touch when the beans all seem to have been ground. There is a ledge and a couple may get trapped on it. The weight can also help generate a better puff as it takes up volume. For the same reason the tube shouldn't be any longer than it need be.

I've run a number of kg through like this with a lot of check weighing. The key is being sure that all of a dose of beans has come out to close limits. That can take a few shots but what is retained is mostly under the burrs so once full doesn't really go anywhere.

You could of course generate the puff of air any way you like.







Maybe a hair drier on cold.

On mazzers some people replace the doser with a funnel. The item is listed on ebay, found by searching octopus funnel. Also on here. Some use other forms of funnel, plastic or what ever. It helps if the diameter is close to the diameter of the doser.

John

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## Paul CS (Dec 2, 2017)

Guys,

Thank you for your detailed responses. I've read them a few times to make sure I got all the points. This is what happened this morning...

"Our beliefs are inversely proportional to easily available facts"

So, here are the facts I gathered this morning.

I weighed 18g of beans.

I ground them into the doser. I used a brush to get as much out is the spout as I could spinning up the machine a few time.

Well I never. 18g came out! What?

Then I removed the top of the grinder and carefully brushed out all the retained coffee I could into the doser. See picture below of the retained coffee before I started that.

















That lot measured just 3g. Not 10g that I stupidly believed. There might be a bit more if I used compressed air.

So what would I tell myself now?

1. The beans that go in do come out;

2. How much of that is exchanged? I don't know but probably not enough to worry about;

3. Get a rubber Lens hood;

4. Worry more about perfecting my technique rather than buying new kit to solve a problem I don't really have.

5. You guys have saved me a lot of money!

Again I would not have worked that out without consulting you guys. Thanks again.

Paul

PS That 18g tasted lovely!


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## Mrboots2u (May 10, 2013)

Excellent news , and we'll worked though there .


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## Sharkie (Apr 29, 2013)

I think it is a standard part for using a different hopper


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