Hydrometer for people with bad eyesight

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Kev888
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Re: Hydrometer for people with bad eyesight

Post by Kev888 » Wed Nov 28, 2018 6:27 pm

FUBAR wrote:
Wed Nov 28, 2018 4:33 pm
I have never done a dark beer since swapping over to the refractometer Kev,so cant answer that one .
Ah, thanks thats helpful to know. I wonder if this may be partly behind the differences people find with them (though I'm sure the devices themselves vary to at least some extent too).

If you ever happen to test it in properly dark wort, particularly higher gravity ones, then I'd be keen to hear if it stays accurate or not. If so then it would suggest something may be wrong with mine.
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Re: Hydrometer for people with bad eyesight

Post by orlando » Fri Nov 30, 2018 8:58 am

This thread might help . Post # 22 by Gunhaus might be the most pertinent.
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Re: Hydrometer for people with bad eyesight

Post by Kev888 » Fri Nov 30, 2018 11:50 am

An interesting thread, but its a real pity he went to all that effort using only sugary water. With cheap refractometers, the issues start to arise with wort, especially darker wort, which deviates from the ideal sugar solution that they expect and distorts their readings. So a wort correction factor is needed, and different darknesses might require different correction factors (unique to the particular device).

That is all pretty much known and established. But when you hear of people having the things agree closely with hydrometers without correction, I have to wonder if my two have been much worse than theirs - which is quite possible given the likely quality control. But its also possible that many people who get on so well with them (or think they do) have never actually tested them in anything very dark.

To put numbers to it, we are talking up to double figures of gravity points in error, or over 1% ABV, in high gravity dark beers, which to me isn't splitting hairs. Yet that can be brought down to within a couple of points with a simple correction factor (and much closer with different factors for different worts), so I think it is worth considering.
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Re: Hydrometer for people with bad eyesight

Post by Aleman » Fri Nov 30, 2018 12:18 pm

That is in effect what I have done ever since getting a cheap optical refractometer. The WCF isn't massively different, but there are times when yes it will make quite a difference ... like my Imperial stouts which resemble Disaster Areas spaceship ... and start at about 1.105. using the 'standard WCF of 1.04 wouldn't cut the mustard

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Re: Hydrometer for people with bad eyesight

Post by Kev888 » Fri Nov 30, 2018 12:32 pm

Ah, many thanks; I was beginning to wonder if I'd just been quite unlucky.

Even wort made with pale spray-malt can be several points out by 1.065, but dark ones are much further away. I've tried using one factor for light-to-mid wort and one for dark, but like you I'm finding that isn't really enough when you get into the really dark ones. Though the light/dark threshold becomes so vague by that point that its a bit of a guess in any case.

That said, it isn't hard to do, and I certainly wouldn't be without the refractometer on brewday. It just compliments rather than replaces hydrometers, in my case.
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Re: Hydrometer for people with bad eyesight

Post by orlando » Fri Nov 30, 2018 1:36 pm

Kev888 wrote:
Fri Nov 30, 2018 12:32 pm
Ah, many thanks; I was beginning to wonder if I'd just been quite unlucky.

Even wort made with pale spray-malt can be several points out by 1.065, but dark ones are much further away. I've tried using one factor for light-to-mid wort and one for dark, but like you I'm finding that isn't really enough when you get into the really dark ones. Though the light/dark threshold becomes so vague by that point that its a bit of a guess in any case.

That said, it isn't hard to do, and I certainly wouldn't be without the refractometer on brewday. It just compliments rather than replaces hydrometers, in my case.
Graham's notes on Beer Engine are quite illuminating about the deficiencies of a device being used for something it was never intended for. Have you read it? Basically he advocates calibrating against every wort, that may deal with the dark beer issue.
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Drinking: From Russia With Love (RIS), Sweet Mild O'Mine (Reprise), All About That Bass

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Re: Hydrometer for people with bad eyesight

Post by Kev888 » Fri Nov 30, 2018 7:07 pm

Ah, thanks. Yes, I agree with Graham - it is exactly my point. There is also some good stuff by/at SeanTerrill.com if I recall correctly (though in blog form so not very accessible).

But.. people seem to be saying their refractometers need little or no correction for use with wort - which goes against the science of how they work (since the wort affects the refractive index through other means than just gravity). This 'should' only be possible if all the wort tested was of a similar, pale shade where the difference is minimal.
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Re: Hydrometer for people with bad eyesight

Post by orlando » Sat Dec 01, 2018 8:49 am

In the end what are we looking for? Commercial outfits have to have precision because HMRC demand it, we don't. The only thing that matters to us is, will it be a bottle bomb? Otherwise it's just a case of getting 3 readings the same at the end. For that use a hydrometer. Personally I use nothing else and yes I have a refractometer. I'm over it.
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Re: Hydrometer for people with bad eyesight

Post by Kev888 » Sat Dec 01, 2018 10:52 am

I suppose it depends on what you consider good enough accuracy, really. Personally I feel that being e.g. nine or ten points out is so sloppy that the measurement would be pointless (hence the WCF), but then some people wouldn't even measure gravity (and will still make beer), so each to their own.

My own take is that its very easy to brew beer, but more challenging to brew it with predictable results. For that, a degree of consistency is needed, and being able to assess it through things like efficiency and OG is handy. Within reason, anyway - as you say, being confident of FG is probably the most important, and even that is more about incremental differences than absolute accuracy.
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Re: Hydrometer for people with bad eyesight

Post by orlando » Sat Dec 01, 2018 12:11 pm

Of course the degree of difference is important and being aware of the potential problems paramount. I just don't see why a refractometer is necessary. You just don't get those problems with an hydrometer. The advantage of only using a few drops is somewhat banal to me. As for time saving I reserve a similar view. As something of a control freak I'm right behind your comments on predictable results, another reason why I use the hydrometer exclusively, the "error" is always the same and replicable. :wink:

Having been on here for 7 years now I shouldn't be surprised by subjects resurfacing on a regular basis. I bet if I searched my posts (I'm not going to, there are quite a few :D ) I would find similar comments to this time, I haven't changed my mind. Welcome to Groundhog Day. :lol:
I am "The Little Red Brooster"

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Drinking: From Russia With Love (RIS), Sweet Mild O'Mine (Reprise), All About That Bass

Up Next: Peaches, Reasons To Be Beerful
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Re: Hydrometer for people with bad eyesight

Post by Kev888 » Sat Dec 01, 2018 12:30 pm

Yes, the refractometer certainly isn't necessary. I mostly find it convenient during sparging, where the gravity changes with time so quick measurements give more up to date results. But it doesn't matter with batch sparging, and I've more or less returned to hydrometers for dark beers, partly because (aside from any accuracy) my refractometer gets harder to read.

I might find more benefit when small batches are begun. The FV won't be deep enough for a hydrometer and I don't like returning samples to the FV. But use at that stage would mean correcting also for alcohol, so another aspect to deal with.

Currrently I only use hydrometers after fermentation begins, though it should be remembered that these need correcting for alcohol too. It is simply built into the 'apparent' attenuation our ABV formulas employ, so we tend not to do it as a separate step.

Sometimes it is worthwhile to repeat things. Not everyone will search before posting or even know/remember that there is anything to consider. Especially with a memory like mine :lol:
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Re: Hydrometer for people with bad eyesight

Post by orlando » Sat Dec 01, 2018 12:46 pm

Your memory is phenomenal, compared to mine, sorry that isn't saying much. For example, I had forgotten about your small batch plans so a refractometer borders on essential. As you say, can't return the samples to the FV.

Mea Culpa. I don't always search before posting, I sometimes don't even remember what appeared earlier in the thread. :roll:
I am "The Little Red Brooster"

Fermenting: Summer Sunshine
Conditioning:
Drinking: From Russia With Love (RIS), Sweet Mild O'Mine (Reprise), All About That Bass

Up Next: Peaches, Reasons To Be Beerful
Planning: Summer drinking Beer.

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Re: Hydrometer for people with bad eyesight

Post by PeeBee » Sat Dec 01, 2018 6:15 pm

orlando wrote:
Sat Dec 01, 2018 12:11 pm
... I just don't see why a refractometer is necessary. ...
Come off it! Refractometers ARE necessary; you look dead cool peering through them for a start and ... OW! ... sorry, just hit me head on the doorpost. I really should stop wearing sunglasses indoors. 8)

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Re: Hydrometer for people with bad eyesight

Post by Aleman » Sat Dec 01, 2018 6:50 pm

If you are using an accurate hydrometer your sample size is somewhere between 300 and 500ml (possibly greater with the really good ones), It's a significant proportion of a 20L brew ... and getting 3 readings the same over three days or so ...

They are just tools at the end of the day, and frankly, none are better / worse than the other, it's just what tools do you want to use /are comfortable using.

I'll be honest and say I only take an OG reading and then after x period of days I keg and take another reading, I have enough experience, and fermentation control to be able to know when a beer is finished, so it's only ever for reference

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Re: Hydrometer for people with bad eyesight

Post by guypettigrew » Sat Dec 01, 2018 8:01 pm

Refractometers (almost) all the way for me!

Mine agrees with the hydrometer, although I've never tried it on a really dark brew.

It's incredibly useful to check last runnings on a sparge, pre boil to work out mash efficiency, and then OG in the FV. I know it's only 100ml to use a hydrometer but, as my H and R agree, it seems a pointless waste of beer.

Once in the FV a Tilt tells me what's going on.

After the mash and boil I'm not too worried about the gravity. I've made what I've made! TBH, the bubbles coming through the blow off tube are just as useful to me as the readings from the Tilt!

The real interest for me is maximising the mash extract efficiency (currently about 95%) and the post boil efficiency figure (currently only about 80%). Not good, trying to work out how to improve it.

Guy

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