Refractometer

[AndrewQLD]

Though I'm not sure how big the loss is through evaporation or whether it is even big enough to worry about.
How do people cool down the solution before putting on the refractometer?
Any chemical engineers out there to do the calculations? I guess it would strongly depend on humidity.

Cheers,
Petr

I use a small syringe, grab a sample pre-boil and test at my leisure, then grab another sample post boil and test when cooled, usually only takes a few minutes to cool down and I have never seen a loss due to evaporation so the reading is accurate. Micro syringes are the best, very small volume and cool quickly.

Sammus Posted Today, 01:50 PM
They annoy me. I have to take about 6 readings, and then I take the two that agree (if I'm lucky there will be two) from that lot as my reading... which is normally way off what my hydrometer says anyway. On top of that the little steel pin holding the lens cover was loose and i finally lost mine last night.. looks like ill have to dodge it up with a nail or piece of wire or something.

I can take a reading 1/2 a dozen times from the syringe and it is the same every time, perhaps you are getting varying readings from evaporation or heat.

I now only use my Hydro for post fermentation readings.


Cheers
Andrew

 

[PJO]

I use a small syringe, grab a sample pre-boil and test at my leisure, then grab another sample post boil and test when cooled, usually only takes a few minutes to cool down and I have never seen a loss due to evaporation so the reading is accurate. Micro syringes are the best, very small volume and cool quickly.

I now only use my Hydro for post fermentation readings.
Cheers
Andrew

That sounds like a good way to deal with it, didn't think about syringes.
Do you use a simple plastic one?
How does it hold up to boiling temps?

I have found that a refractometer is next to useless for readings during and post ferment as the suspended yeast make the line very indistinct. Only once the beer is clear does it become useful again.

Cheers,
Petr

 

[Screwtop]

I use a small syringe, grab a sample pre-boil and test at my leisure, then grab another sample post boil and test when cooled, usually only takes a few minutes to cool down and I have never seen a loss due to evaporation so the reading is accurate. Micro syringes are the best, very small volume and cool quickly.
I can take a reading 1/2 a dozen times from the syringe and it is the same every time, perhaps you are getting varying readings from evaporation or heat.

I now only use my Hydro for post fermentation readings.
Cheers
Andrew

Identical to my use, I put the tip of the dropper under the surface of the hot wort and squeeze to get a good sample then squirt that back, do this a couple of times to make sure there is no condensate or any of the last sample in the bulb then take it out and slowly invert, some hot wort will squirt out then it's safe to lift out from the pressure change, squirt back all but a tiny bit in the bulb, swirl and lay that on the bench for a minute or two, by then this small sample has cooled, drop two drops on the lense and take your reading.

Like Andrew I tried multiple readings in the early days of using the Refrac but they were all the same so long as I too small samples and allowed them to cool. Once put some hot wort straight on the lense and the reading was so way off. Next reading confirmed that the hot sample was way out, so never did that again.

They're fantastic for fermentation monitoring. Use a Pet bottle cap, take a small sample through the tap (spray sanitiser up into the tap post sample) catching it in the cap. Then mostly out of laziness - dip the bulb end of the dropper into the wort, enough will cling on to provide one drop onto the lense, repeat for two drops and take your reading (saves washing out the dropper post use, just spray the bulb with sanitiser and wipe to put away). Enter the reading into Beersmith's Refractometer Tool and select Fermenting Wort for the corrected reading. When the readings are the same over three days it's stopped. Then during racking/keging take a Hydro sample, it's always the same as the corrected Refrac reading for me, but I like to check.

Screwy

 

[Hogan]

For those who draw a sample from the top of the final runnings - make sure you stir the kettle well before you sample - otherwise you will get a low brix reading.

I say this because I have made this error and lost a few more grey hairs thinking, 'good lord what has happened to my efficiency'.

Cheers, Hoges.

 

[AndrewQLD]

That sounds like a good way to deal with it, didn't think about syringes.
Do you use a simple plastic one?
How does it hold up to boiling temps?

Cheers,
Petr

Just plastic ones, haven't had a problem yet with the wort temp effecting the plastic, but it does cool quickly.

 

[SpillsMostOfIt]

Just plastic ones, haven't had a problem yet with the wort temp effecting the plastic, but it does cool quickly.

I got one from the chemist for free and the one I bought from the HBS cost me fitty cent, so even if you only get a few brews out of each unit, they are (IMO) good value and less wasteful than if they were put to some extravagant medical use...

 

[Screwtop]

For those who draw a sample from the top of the final runnings - make sure you stir the kettle well before you sample

Important point above - stir before taking all pre and post boil readings.

 

[pint of lager]

When taking readings of the last runnings while sparging, to make sure the brix is not too low, I use a dropper, in a manner similar to Andrew's and draw straight from the runoff tube.

Your lens must be perfectly clean and dry, any dried wort or water will affect your reading.

Many brewers struggle when making the switch from hydrometer to refractometer, but it is worth the grey hairs. If you were used to a refractometer and had to switch to a hydrometer, you would struggle just as much.

 

[SpillsMostOfIt]

If you were used to a refractometer and had to switch to a hydrometer, you would struggle just as much.

But you'd still be left using a hydrometer, so the bitter taste of sad irony would remain...

 

[SJW]

I am thinking about getting one of these but after reading all this and printing off the charts and comparing with Beersmith I am finding a big variation in answers. I am wondering if it's worth it? Screwy is the onlt one who offers a little hope with the way he does it. Just from what I have seen Doc's table does not appear to line up with what Beersmith says. I generally get a variation of 2 points between what the tables say and what Beersmith says. And from what I am reading getting a consistant Refractometer reading is a challenge too.
But cooling the pre boil sample down is a pain.......I dont know what to do..................

Steve

 

[drsmurto]

If you calibrate the refractometer with water, and then take readings with a hydro of fermenting and fermented wort beersmith works out a correction factor.

I havent use my hydro in the last few batches.

 

[crozdog]

I am thinking about getting one of these but after reading all this and printing off the charts and comparing with Beersmith I am finding a big variation in answers. I am wondering if it's worth it? Screwy is the onlt one who offers a little hope with the way he does it. Just from what I have seen Doc's table does not appear to line up with what Beersmith says. I generally get a variation of 2 points between what the tables say and what Beersmith says. And from what I am reading getting a consistant Refractometer reading is a challenge too.
But cooling the pre boil sample down is a pain.......I dont know what to do..................

Steve

Steve,

Just do it. I reckon the refractometer is 1 of the best bits of brewing gear you can buy. Like any new bit of kit, you need to work out it's inherrent perculiarities and your process for using it. you can't do that if you don't have 1 can you? B)

2 points is very easy to make a mistake with when using a hydro due to bubbles, and the small scale of most hydro's. Remember it's an art as well as a science

Attached is a spreadsheet I made and printed out to allow me to look up the conversions. I've put it in a plastic sleeve & use a fridge magnet to hang it on my keg fridge in the shed. Hope you find it useful

crozdog

View attachment refractometer.xls

 

[Cortez The Killer]

I don't know how I'd go without my refractometer. It's definitely worth having one. Beats a hydrometer any day

There doesn't seem to be anything conclusive about converting Brix to SG however

I did make this table a while ago that comes in handy http://www.aussiehomebrewer.com/forum/inde...st&p=237324

Even with a 2 point margin for error if you take a refractometer and a hydrometer reading you can use this variance to correct future readings or draw up your own table based on the formula which best fits your results.

The only time I've had issues taking a reading is when there's been a lot of yeast in suspension

If funds permit - I'd definitely go for the refractometer

Cheers

 

[SJW]

Does it make a diff if u a brewing a dark beer like a stout? I read that these things are designed for clear sugar solutions. Also what impact does hops have on it when you take a sample close to the end of the boil?

Steve

 

[drsmurto]

the layer of wort on the refractometer is very thin so its not a problem. I brewed a stout last weekend and had no issues at all seeing the line.

Start/end of the boil makes no difference. I let the sample cool down first before taking a reading

 

[SJW]

Do u or did u ever double check your reading with a Hyrometer? how did it go?

 

[drsmurto]

I did the first few times i used it but dont these days altho i did double check the stout as i had an extra litre of wort! Once you calibrate it properly and against the hydro in beersmith you are set. I only ever use the hydro if i want to taste the beer along the way.

That said, i pour out 1/2 cup and use it for both the refract reading and the taste test!

EDIT - the refract and hydro agreed.

 

[SJW]

Done deal. I will go and get one tomorrow. Thanks boys, and Leeboy.

 

[glennheinzel]

The info above will come in handy as I just bought one off ebay.

FYI - There are a range of models on ebay. The different models that I could identify are-
1) Base model which needs a mini screwdriver to calibrate.
2) Model which has a calibration knob built into it.
3) Model with LED light built into it. ie, You need to point the first two models at a light source to get a reading whereas this has the light source built in.

Now I have to work out what is the next toy to buy...

Edit: Removed damn emoticon which showed up when it wasn't wanted.

 

[BrissyBrew]

MashMaster will be releasing a refractometer with brix 32% and SG for unfermented wort in the near future (as soon as I get around to taking some product pics), the SG scale has been calibrated to the approximate the average larger/light ale in colour. Saves having to think too hard on brew day when testing your runnings from your mash tun or kettle.