Refractometers - worth having?

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vacant
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Re: Refractometers - worth having?

Post by vacant » Sun Nov 30, 2014 12:06 pm

IPA wrote: Just made up my mind to buy this and guess what. THIS ITEM IS NOT AVAILABLE FOR DELIVERY TO FRANCE what's up with them? Don't they know that a probe has just landed on a comet 300 million miles away from earth? We are at the nearest point only 22 miles from the Un-United Kingdom
http://www.amazon.fr/R%C3%A9fractom%C3% ... ractometre
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Re: Refractometers - worth having?

Post by Aleman » Sun Nov 30, 2014 12:10 pm

IPA wrote:
6470zzy wrote:Many refractometers intended for the homebrew market now come with the specific gravity graduations already so that there is no need for any calculations on the brewers part. I only wish that I had been able to control my urge to purchase a refractometer until I had seen one of these. :oops:

http://www.amazon.co.uk/gp/product/B00A ... MXSBXMW3W7

Cheers
Just made up my mind to buy this and guess what. THIS ITEM IS NOT AVAILABLE FOR DELIVERY TO FRANCE what's up with them? Don't they know that a probe has just landed on a comet 300 million miles away from earth? We are at the nearest point only 22 miles from the Un-United Kingdom
No idea why they can't ship to the UK, but I will iterate my earlier posts that the SG scale may not be the most accurate because the relationship between SG and Brix is not linear. . . .OK some of these refractometers appear to be reasonably close but depending on the Chinese supplier at the time they may not all be.

Also consider how easy it is to read, with a dual scale one the divisions are twice as close together, as in a single scale one odd divisions are on one side and even on the other - Compare
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Re: Refractometers - worth having?

Post by IPA » Sun Nov 30, 2014 3:35 pm

vacant wrote:
IPA wrote: Just made up my mind to buy this and guess what. THIS ITEM IS NOT AVAILABLE FOR DELIVERY TO FRANCE what's up with them? Don't they know that a probe has just landed on a comet 300 million miles away from earth? We are at the nearest point only 22 miles from the Un-United Kingdom
http://www.amazon.fr/R%C3%A9fractom%C3% ... ractometre
Thanks for the link. I did in fact look on Amazon France but as always they are more expensive than the UK in as much as they say free postage but it works out at about the same the UK price plus postage. Internet selling and buying are still in their infancy here. In the end I ordered the same model from Wun Hung Lo for £16 including postage.
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Re: Refractometers - worth having?

Post by Brewhunter » Mon Dec 01, 2014 11:41 pm

I've just ordered a cheap and cheerful one direct from China,
I'll let you guys know how I get on..
Apparently they can be temperamental if used outside of a certain temperature range?

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Re: Refractometers - worth having?

Post by jmc » Tue Dec 02, 2014 1:55 am

Sorry, late to this one.

I've had an eBay Chinese one for a few years and I wouldn't be without it.

Its really useful on AG brew days for testing wort SG, but I also use mine for the whole brewing cycle.

As other's have mentioned the SG scale (if accurate) is only valid before fermentation as alcohol distorts the figures, but there are tables to compensate for this
I use a printout of an Excel calc sheet that's a modified version of one that originally came from the More Beer site

Even if you don't trust the tables, the brix reading on the refractometer does go down as sugars are fermented, so you can always use it as a rough guide to fermentation progress, and more importently when fermentation has stopped and SG/Brix remains constant.
I don't add SG samples back to a brew so I'm very happy I just take about 5cc each time from a tap in the FV into a sample vial.
Much better than losing 100-200cc each SG measurement.

The only gotcha that took me a while to find out was that the 'ATC' doesn't always work. I think it assumes the refractometer will be the same temp and the sample will be adjusted by the greater thermal mass of the refractometer.

My kit is in a garage which varies in temp significantly day to day. I always calibrate mine (with tap water) every day I take a measurement. 2-3c difference will give a different zero point on mine.

Enjoy your Christmas present Jim :)

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Re: Refractometers - worth having?

Post by MTW » Thu Dec 18, 2014 10:54 am

Do you all tend to just blob the sample drop onto the plate at mash temperature and trust it to cool enough instantly, or leave it in the dropper for a few minutes...force cool...or what?
Aleman wrote:Also consider how easy it is to read, with a dual scale one the divisions are twice as close together, as in a single scale one odd divisions are on one side and even on the other - Compare
Are they really that much easier to read? It looks like you've still got 32 Brix spread over the same distance in the viewfinder. There are more Brix divisions marked on, though the overall resolution looks the same, if you see what I mean...it's not like its a narrower Brix range across the field of view, or a wider viewfinder...(?)
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Re: Refractometers - worth having?

Post by DeadFall » Thu Dec 18, 2014 1:02 pm

I read it instantly when I'm measuring during sparging. When I'm taking the pre-boil OG and post boil OG I leave it for a minute.
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Re: Refractometers - worth having?

Post by jmc » Thu Dec 18, 2014 2:16 pm

MTW wrote:Do you all tend to just blob the sample drop onto the plate at mash temperature and trust it to cool enough instantly, or leave it in the dropper for a few minutes...force cool...or what?
Aleman wrote:Also consider how easy it is to read, with a dual scale one the divisions are twice as close together, as in a single scale one odd divisions are on one side and even on the other - Compare
Are they really that much easier to read? It looks like you've still got 32 Brix spread over the same distance in the viewfinder. There are more Brix divisions marked on, though the overall resolution looks the same, if you see what I mean...it's not like its a narrower Brix range across the field of view, or a wider viewfinder...(?)
I always calibrate each day before doing any measurements, as change in ambient temp affects mine.

I take a sample into a plastic shot glass, leave it to cool for a couple of mins and then take a measurement.

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Re: Refractometers - worth having?

Post by Aleman » Thu Dec 18, 2014 8:16 pm

I put a drop in the sample well and push the 'measure' button every 10 seconds, or so, until Iget three readings the same. Yes I does tale time to stabilise. The same is true of an optical instrument. . . Normally 30 to 45 seconds before the reading is stable.

My optical refractometer is a 20 brix one and considerably easier to read

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Re: Refractometers - worth having?

Post by IPA » Fri Dec 19, 2014 9:57 am

Wun Hung Lo came up trumps this time it arrived in 17 days and I must say it is delightfully easy to use
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Re: Refractometers - worth having?

Post by guypettigrew » Sat Dec 20, 2014 6:16 pm

jmc wrote:As other's have mentioned the SG scale (if accurate) is only valid before fermentation as alcohol distorts the figures, but there are tables to compensate for this
I use a printout of an Excel calc sheet that's a modified version of one that originally came from the More Beer site
Thanks--I think!

So how do I use this table to work out SG as the fermentation progresses, please? The idea of only using a few ml of brew rather than running 100ml out into a test jar really appeals.

As an example. If I have a brew which starts at 1.050 and I want to know when it's reached 1.012ish, how would I use the table?

Thanks.

Guy

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Re: Refractometers - worth having?

Post by DeadFall » Sun Dec 21, 2014 12:00 am

guypettigrew wrote:
jmc wrote:As other's have mentioned the SG scale (if accurate) is only valid before fermentation as alcohol distorts the figures, but there are tables to compensate for this
I use a printout of an Excel calc sheet that's a modified version of one that originally came from the More Beer site
Thanks--I think!

So how do I use this table to work out SG as the fermentation progresses, please? The idea of only using a few ml of brew rather than running 100ml out into a test jar really appeals.

As an example. If I have a brew which starts at 1.050 and I want to know when it's reached 1.012ish, how would I use the table?

Thanks.

Guy
CBA to look now, but there's a few calculators around on the net. Most work in Brix, but there's a few out there that work with SG. I usually just sanitize my hydrometer and leave it in the fv at that point. The refractometer really pays for itself on brew day. Though I'll never buy another hyrdometer so I'll need those calcs one day :)
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Re: Refractometers - worth having?

Post by barry44 » Tue Dec 23, 2014 3:59 pm

Really happy with mine. I use it for all stages of the brew and ferment.

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Re: Refractometers - worth having?

Post by jmc » Wed Dec 24, 2014 1:24 am

guypettigrew wrote:
jmc wrote:As other's have mentioned the SG scale (if accurate) is only valid before fermentation as alcohol distorts the figures, but there are tables to compensate for this
I use a printout of an Excel calc sheet that's a modified version of one that originally came from the More Beer site
Thanks--I think!

So how do I use this table to work out SG as the fermentation progresses, please? The idea of only using a few ml of brew rather than running 100ml out into a test jar really appeals.

As an example. If I have a brew which starts at 1.050 and I want to know when it's reached 1.012ish, how would I use the table?

Thanks.

Guy
If OG is 1050, then chart assumes OG in Brix was 12.5.

Look at 12.5 row, go to right untill SG target (1012)
Go to top; 6.5brix
So with this chart you'd expect a brew with OG 1050/12.5Brix to be at 6.5Brix when SG is 1012

Simples ;)

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Re: Refractometers - worth having?

Post by guypettigrew » Fri Dec 26, 2014 12:12 pm

Ah yes. Thanks. Embarrassingly simple when you know how!

I'll print out the PDF, laminate it and stick it on my brew room wall.

Thanks again.

Guy

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