# Bonavita Immersion Cone



## MWJB (Feb 28, 2012)

Had a run through with this today & quite pleased with the result. My current IMM beans are at work, but I found some Columbia Descanso roasted a month ago. The brewer comes with some Melitta filters to get you going (I already had some Filtropas so used these). It also comes with instructions on brew ratios (~58g/l, there's a neat little chart, coarse drip grind) & steep times (fill, cover for 2mins, stir & cover for another 1-2 min & draw down). I was keen to see if I could replicate my preferred brews with the old, clear Clever Dripper (which I foolishly gave away) so I went back to what I had been doing previously - finer grind, longer steep & higher end extraction level.

Preheated the brewer & filter with boiling tap water whilst waiting for Volvic to boil. Drained the preheat & added most of the 'just off boil' brew water, then grinds (62.5g/l) & wet, then topped up with remaining brew water (to stop any grounds from overflowing the filter, or sticking to it above the tide mark). Tasted from ~10min, drew down at 25:00, 3 and half mins draw down.

I was expecting a 25% immersion yield and I got...

  

I was hoping the Bonavita would hold heat better than the Clevers, due to the porcelain construction, but temperature of the slurry was ~57C at draw down, despite the preheat, so no improvement on that front. Following the supplied instructions would no doubt net you a hotter cup, but I'd rather have honey sweet, warm coffee than hotter coffee that's less sweet (I'm not saying you can't get tasty coffee in less time, just this is how long it took to hit my preference, with this bean & grind). This steep time is probably verging on 'worst case scenario' as I used the Rocky, I don't have an explanation as to why, but grinding on the Porlex seems to result in a faster extraction (~10min...I can hear Gary shouting "Fines!"). I'll try a Porlex brew at the weekend.


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## dsc (Jun 7, 2013)

57degC is not bad for a 25min brew, it's porcelain so think of it like a big mug, I'm actually surprised it held up at almost 60degC at the end of it.

You must be getting very little fines from your Porlex, or am I missing something?

Regards,

T.


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## MWJB (Feb 28, 2012)

Hi Tom,

The Porlex, from my records with the old CCD, gets up to desired yield quicker, even at what appears to be a coarser grind. I don't really have any surefire way of determining proportion of fines (I have tried eyeballing grinds with a magnifier & sheet of paper - both grinders are set to where there appears to be least difference in grind size...but after a point everything just looks "small" & so difficult to draw conclusions without a more scientific process). So I can only speculate as to why this is...draw down time didn't seem to vary greatly between the 2 grinders, but I don't know whether this is significant regarding brewer design (new CCD seems to draw down quicker then the old one) amount of fines, or the shape of grinds/fines, or any other factors like surface texture of the grinds? Just thinking out loud...


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## Neill (Jun 26, 2013)

Great write up, thanks. Definitely on my to get list.


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## dsc (Jun 7, 2013)

I always thought hand grinders generate a lot more fines, as the shaft is not held dead on center and it wobbles, especially when there's very little beans left in the top chamber. As you say it's hard to judge just by looking at the grinds, you'd need a set of precise filters to sift the grind and see what the different sized particle amount is.

Which one do you prefer, Bonavita or CCD?

Regards,

T.


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## Neill (Jun 26, 2013)

dsc said:


> I always thought hand grinders generate a lot more fines, as the shaft is not held dead on center and it wobbles, especially when there's very little beans left in the top chamber. As you say it's hard to judge just by looking at the grinds, you'd need a set of precise filters to sift the grind and see what the different sized particle amount is.
> 
> Which one do you prefer, Bonavita or CCD?
> 
> ...


This is where the likes of the made by knock grinder looks interesting.


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## garydyke1 (Mar 9, 2011)

I modded my Porlex to be more stable , the fines are visibly worse than my Maestro+, which in turn are visibly worse than an Ditting 1203 : (


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## MWJB (Feb 28, 2012)

dsc said:


> I always thought hand grinders generate a lot more fines, as the shaft is not held dead on center and it wobbles, especially when there's very little beans left in the top chamber. As you say it's hard to judge just by looking at the grinds, you'd need a set of precise filters to sift the grind and see what the different sized particle amount is.
> 
> Which one do you prefer, Bonavita or CCD?
> 
> ...


Either the Bonavita, or an old CCD, they seem pretty comparable. The new, smoked plastic, CCD seems a bit trickier to get consistent results from, so if buying new - the Bonavita... but I wouldn't chuck out an old, clear plastic, working Clever to buy it.


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## dsc (Jun 7, 2013)

Hmm, I might give that Bonavita a try then. Where did you get yours?

As for Porlex vs Ditting, the poor Porlex is bound to loose I think it's also down to the size of the burrs and how they are cut (ie. aim at espresso or brewed), I don't really like conical hand grinders for brewed as it will produce more fines by default (it's more suited for espresso in my opinion).

Regards,

T.


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## MWJB (Feb 28, 2012)

dsc said:


> Hmm, I might give that Bonavita a try then. Where did you get yours?.


Coffeehit, they're the UK Bonavita importer.


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## Charliej (Feb 25, 2012)

dsc said:


> Hmm, I might give that Bonavita a try then. Where did you get yours?
> 
> As for Porlex vs Ditting, the poor Porlex is bound to loose I think it's also down to the size of the burrs and how they are cut (ie. aim at espresso or brewed), I don't really like conical hand grinders for brewed as it will produce more fines by default (it's more suited for espresso in my opinion).
> 
> ...


My 1940s Zassenhaus 496 hand grinder has its shaft and bottom burr held on centrally and produces a much better grind whether in the espresso range or for brewed and( although not difficult) a lot less fines than my Porlex, it gets used exclusively for when I feel like a brewed coffee rather than espresso.


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## dsc (Jun 7, 2013)

Got this brewer as a gift for Christmas. So far I'm rather impressed with the brews, super clean and almost no effort. I'm using 60g / l, on the finer scale of a coarse grind (that's super scientific), leaving it for 8min.

Regards,

dsc.


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## dsc (Jun 7, 2013)

Recently I started using this brewer again after using the Chemex for a while. Strange thing is that no matter what grind setting changes I do, the TDS seems to stay at the same level, pretty high as well reading 1.4% almost everytime. I've started with a Chemex grind level, which was 170, moved through 185 all the way to 200 and I'm still getting 1.4% in the cup, although the brew tests pretty differently at different grind setting.

Is it due to the mixed nature of the brew ie. immersion + filter at the end? It's damn hard to nail anything as I'm not really sure what ext. yield I'm getting.

I will give 170 setting a try again, although I might have to cut the coffee dose a bit. Mojo software seems to suggest almost 28g for 400g of brew water, which seems a bit excessive.

Regards,

T.


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## Glenn (Jun 14, 2008)

Cut the dose for sure. Sounds counter intuitive but will help.

The issue could also be the immersion time. Try adjusting this variable first.


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## dsc (Jun 7, 2013)

I decided to give Rao's method a try again, so all water in in one go, stir the bloom till there's nothing floating anymore, brew for 4min, stir, drain. I end up with a flat bed of coffee, nothing stuck to the sides of the filter, but at a grind setting of 170, the coffee was super strong. I've decided to go coarser to fight the strength, but it went too far I think. I think stirring might be affecting the TDS pretty heavily.

Regards,

T.


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## MWJB (Feb 28, 2012)

Going coarser will reign back extraction, adjust dose to bring strength in line.

I tend to brew around 62-65g/l.

When you say it's super strong, is that TDS-wise, or mouthfeel?


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## dsc (Jun 7, 2013)

I thought coarser with mean lower TDS, but that doesn't seem to be the case on the Bonavita. It worked on the Chemex though.

Strong both TDS and mouthfeel, on the verge of too bitter.

I went with 60g/l, got 1.22% TDS and 340g of brew, that's close to 21.5% ext. yield according to the Mojo sofware. Taste wise it's not superb, mixture of slightly too bitter and sour. Can't really seem to nail these Bonavita brews.

Regards,

T.


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## Glenn (Jun 14, 2008)

Turbulence is an issue. Try not stirring and see what happens.


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## MWJB (Feb 28, 2012)

Going coarser with the chemex, you can go coarser still maintain the ext yield. Not so easy with the Bonavita. Coarser grnd pretty much means a lower yield. 24%+ Imm Yield would be my target.

To thin out the mouthfeel, preheat the brewer, then add brew water first.

I'd be expecting ~1.4%TDS for 60g/l...unless you also use a permanent filter like a Kone or Swissgold, then more like 1.25%TDS (%TDS usually drops as the coffee can drain around the bed, rather than through it).

It's tricky to get below a certain %TDS for a given brew ratio (with just the paper filter), because what the brew doesn't pick up during the steep phase, it then picks up at draw down.


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## dsc (Jun 7, 2013)

Well I was getting 1.4% for pretty much anything grind wise, from fine grind to boulders, it must be the additional TDS picked up when it draw down. This makes the method pretty hard to nail, as you don't really know where you are TDS /ext. wise. With the Chemex it was pretty easy, if the TDS / ext. yield was too much I'd go slightly coarser on the grind and the TDS would drop, if it was too low I'd grind finer.

I might just stick to Chemex for now.

Regards,

T.


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## MWJB (Feb 28, 2012)

dsc said:


> Well I was getting 1.4% for pretty much anything grind wise, from fine grind to boulders, it must be the additional TDS picked up when it draw down. This makes the method pretty hard to nail, as you don't really know where you are TDS /ext. wise. With the Chemex it was pretty easy, if the TDS / ext. yield was too much I'd go slightly coarser on the grind and the TDS would drop, if it was too low I'd grind finer.
> 
> I might just stick to Chemex for now.
> 
> ...


The Bonavita is easier & more consistent than Chemex, or any other brewer where flow is involved in the main extraction. You get a more even cup too (less layering). Grind fine, just coarser than espresso, set your preference in the VST software to 25% Imm Yield (you can land a % either way with good results). 60-65g/l should give you in the region of 1.4-1.55%TDS (depending on the ratio), concentration sounds high, but because the brewed coffee is then filtered through the bed as well as the filter paper, the body & strength perception is less, if you add water 1st. Add coffee 1st and you get a layer of goo in the bottom of the brewer and a thick, oily mouthfeel.


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## dsc (Jun 7, 2013)

I keep hearing that

I have 20% set in the preferences as the target coffee extraction, but I can only go as high as 21%. Also for 400g of brew water and 1.3% TDS it suggests almost 28g of coffee which is a bit excessive imho.

Regards,

T.


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## MWJB (Feb 28, 2012)

dsc said:


> I keep hearing that
> 
> I have 20% set in the preferences as the target coffee extraction, but I can only go as high as 21%. Also for 400g of brew water and 1.3% TDS it suggests almost 28g of coffee which is a bit excessive imho.
> 
> ...


Weird, I can set mine to 25% (Windows version)? It says to go 56g/l for 1.32%TDS.

28:400g will probably net you 1.5-1.7%TDS.


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## MWJB (Feb 28, 2012)

Duplicate post deleted.


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## MWJB (Feb 28, 2012)

My Bonavita no longer seals properly at the shut off valve. If you have one, don't brew with it unattended, nor try a cold brew in it. Play safe & leave it brewing seated on a carafe (an empty one, not one half full of preheat water, that'll overflow like mine did).


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## dsc (Jun 7, 2013)

I always wondered how long that silicone seal with live, sure you haven't got some coffee stuck to the lip which is stopping it from sealing?

Regards,

Tom


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## MWJB (Feb 28, 2012)

Hi Tom,

Yes sure, no coffee trapped around the lip/valve. The silicone itself looks OK, I always left it with the valve open when not in use so as not to deform the switch, but it's not holding back the brew properly anymore. There are a few cases noted on the Amazon reviews of this happening after a few months of ownership/use.

I guess periodic, careful adjustment might help, it's just a bind that I can't set & forget it anymore.


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## Step21 (Oct 2, 2014)

I tried a few brews with the Bonavita Immersion brewer yesterday to see if i could get close to the quality of my French Press extractions. I didn't get there - all slightly under extracted. I think the reasons for is are that

1. i'm brewing at about half the capacity for the brewer.

2. The brewer loses heat quicker than the FP, so the extraction is not as good as it could be. Due to heat loss the brew needs to be quicker than a FP (certainly at half capacity).

As i understand it most of the extraction happens in the first couple of mins, so i'd need to employ some agitation strategy to get to the same place more quickly. Which begs the question of how much and when?


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## MWJB (Feb 28, 2012)

If you want to brew quickly in the Bonavita, I find you have to rely on an element of flow, e.g. use it more like a drip brewer but with an augmented bloom: drip grind, coffee & water held together with the valve shut, then top up & drain

Immersion extraction isn't a linear curve, perhaps 50% takes place in the first 30s, 0.5% in the last ten minutes. Agitation may speed up early phase extraction, but overdo it and you'll get bitter brews


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## Step21 (Oct 2, 2014)

MWJB said:


> If you want to brew quickly in the Bonavita, I find you have to rely on an element of flow, e.g. use it more like a drip brewer but with an augmented bloom: drip grind, coffee & water held together with the valve shut, then top up & drain
> 
> Immersion extraction isn't a linear curve, perhaps 50% takes place in the first 30s, 0.5% in the last ten minutes. Agitation may speed up early phase extraction, but overdo it and you'll get bitter brews


Superb brew this evening using a 2 minute "augmented" bloom. In your debt again MWJB!


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## Step21 (Oct 2, 2014)

I've used this augmented bloom technique now on several beans and found that it produces consistently good results. My observation is that it is very similar to pourover and produces a similar type cup. I'm finding it best to kill the brew by shutting the valve after i've got my target brew amount out, as the last part of the brew, just like pourover, isn't terribly tasty.

I wonder how the variables of bloom time and speed/vigour of the fill after the bloom will change the extraction? Plenty of room for more experimentation...


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