An original hydrometer question - or not?

[Vinotinto]

Believe me I have searched. -

The situation is - I have an old but pristine boots hydrometer that has been in the cupboard for the best part of 30 years. When taking up the 'hobby' again I did buy with other gear a new one but only the Wilko usual stock cheapie made by Muntons, as it was not much money anyway.

I have messed about with these for a while but whilst racking the Kenridge Classic today I used both on the sample in the trail jar and, having got two different readings of 0.998 and 1.004 decided to also have a play around with temperatures and water etc etc.

One thing did stand out in the with both hydrometers the individuals readings remained VERY much the same with temperatures between about 18C and 25C. ( so does temp make that much difference in this range? ) Ok , it follows, how accurate is my thermometer but where do we stop with this?

Testing both in tap water adjusted to 20C ( yes, on the unknown accurate thermometer) I actually got similar readings to those above in the wine which suggests to me that the wine at this stage is the same (ish) as tap water at 1.000? With me so far?

I am now left with, assuming ( yes I know ) that the thermometer is accurate ( and the aforementioned suggests that the hydro reading will not be much different anyway within limited temp parameters ) two hydrometers of which I do not know if one or any are actually accurate or if they both are just outside of 1.000 each way as shown above.

Do I / should I continue and try them both with distilled / ro water? Will it / does it matter if just using for wine? Forgot to mention also I am aware that the paper gauges can slip in the tubes too.

To conclude, if you are still awake, should I be concerned at these variances / should I just use one hydrometer and recalculate based on the variance I already have shown against bog standard tap water?

You may now yawn! :grin:

 

[Covrich]

I did find it a little hard to follow all of what you was saying!!

so you tested both at 20ºc did either read 1.000??

 

[Tau]

Believe me I have searched. -

The situation is - I have an old but pristine boots hydrometer that has been in the cupboard for the best part of 30 years. When taking up the 'hobby' again I did buy with other gear a new one but only the Wilko usual stock cheapie made by Muntons, as it was not much money anyway.

I have messed about with these for a while but whilst racking the Kenridge Classic today I used both on the sample in the trail jar and, having got two different readings of 0.998 and 1.004 decided to also have a play around with temperatures and water etc etc.

One thing did stand out in the with both hydrometers the individuals readings remained VERY much the same with temperatures between about 18C and 25C. ( so does temp make that much difference in this range? ) Ok , it follows, how accurate is my thermometer but where do we stop with this?

Testing both in tap water adjusted to 20C ( yes, on the unknown accurate thermometer) I actually got similar readings to those above in the wine which suggests to me that the wine at this stage is the same (ish) as tap water at 1.000? With me so far?

I am now left with, assuming ( yes I know ) that the thermometer is accurate ( and the aforementioned suggests that the hydro reading will not be much different anyway within limited temp parameters ) two hydrometers of which I do not know if one or any are actually accurate or if they both are just outside of 1.000 each way as shown above.

Do I / should I continue and try them both with distilled / ro water? Will it / does it matter if just using for wine? Forgot to mention also I am aware that the paper gauges can slip in the tubes too.

To conclude, if you are still awake, should I be concerned at these variances / should I just use one hydrometer and recalculate based on the variance I already have shown against bog standard tap water?

You may now yawn! :grin:

The one that gave you 0.984 reading the other week is the faulty one.

 

[Vinotinto]

No. One read 0.998 the other read 1.004 in water at 20C

These were Very similar though to the readings I got in the sample. I suppose one may be out on the high side and the other out on the low side. OR the actual true reading lies between the two, hence the enquiry as to whether I should start looking at using them on ro or distilled water.

 

[Vinotinto]

The one that gave you 0.984 reading the other week is the faulty one.

Sorry Tau, I posted the other reply before seeing yours. Yes I remember you questioning that one and that was the old Boots one. I understand where you are coming from on that.

 

[Vinotinto]

So anticipating any other suggestions etc would I be rude to suggest that for a run of the mill wine home brewer's hydrometer that there is no need to go hi tech multi digital whatever thingy! But ......... providing the temperature is right ( suggestions for accurate thermometer appreciated ? ) and I adjust according to the reading against ordinary tap water then I will not be going far wrong?

 

[chewie]

Does the old one have the calibration temp marked on it?

 

[Vinotinto]

Does the old one have the calibration temp marked on it?

Yes , they are both 20C

 

[Tau]

Which hydrometer gave you this reading that Old Pete questioned "with a starting SG of 1.116" which pete said should be 1.095 ?

 

[Vinotinto]

Which hydrometer gave you this reading that Old Pete questioned "with a starting SG of 1.116" which pete said should be 1.095 ?

Tau, that was the older Boots one which does not help really as this one appears to give a lower than actual reading and lower certainly than the newer one.

 

[Tau]

You need to buy another hydrometer of another make, seen youngs for 75p in some tescos at the moment. I have 2 versions of the muntons hydrometer, wilkos hydrometer there is a newer version that has a higher scale, had an sift through all on shelf till found it and a couple of youngs which is smaller and smaller scale but handy for end of fermentaion testing. Have used boots hydrometers in the distant past they were nothing special I recall.

 

[Vinotinto]

Er..... the other one I have IS the Muntons. That was the one showing 1.004 in tap water at 20c.

 

[Mikey]

Test in water at 20c
The one that is high 1.004 offset all readings by -.004
The one that is 0.998 offset readings by +.002

If you want to make sure they're accurate further up the sg scale make a sugar solution using one of them and now see if the other hydrometer says the same reading after both have been calibrated

 

[Vinotinto]

Test in water at 20c
The one that is high 1.004 offset all readings by -.004
The one that is 0.998 offset readings by +.002

If you want to make sure they're accurate further up the sg scale make a sugar solution using one of them and now see if the other hydrometer says the same reading after both have been calibrated

I did this yesterday. I tested at different temps between 18 and 25. Although they read different to each other there was actually no change within thos temps. It follows, how accurate is my thermometer but where do I stop with this and exactly how critical does this become with purely wine making?

Will look at the sugar solution you suggest. Found a good article on two point calibration.

It has also been suggested that I use distilled or ro water to test.

 

[Tau]

In one, the older muntons from wilkos I noticed that there was 0.002 missing from the printed scale between 1.010 and 1.000, there were only 3 lines when there should have been 4, not noticed in the new one. I calbrated in soft bottled water, not hard water which might have a lot of disolved components that the hydrometer might be reading correctly i.e 0.002, if you have the miss print like my older wilkos hydrometer which would give your 1.004 for your tap water. Maybe try calibrating using distilled water. Edit: You can tell if you have the old or new muntons hydrometer, old only reads to 1.120, new reads upto 1.150

 

[Vinotinto]

In one, the older muntons from wilkos I noticed that there was 0.002 missing from the printed scale between 1.010 and 1.000, there were only 3 lines when there should have been 4, not noticed in the new one. I calbrated in soft bottled water, not hard water which might have a lot of disolved components that the hydrometer might be reading correctly i.e 0.002, if you have the miss print like my older wilkos hydrometer which would give your 1.004 for your tap water. Maybe try calibrating using distilled water. Edit: You can tell if you have the old or new muntons hydrometer, old only reads to 1.120, new reads upto 1.150

Appreciate your time and effort with this Tau

Muntons goes to 1.150 and nothing missing between the lines.

Did the 2 part test today.
In tap water at 20c
Old boots actually read 1.000 ( 0.998 yesterday ) is it me?
Muntons 1.004 ( 1.004 yesterday )

Sugar solution 24g in 176g of water to give 12degree Plato - target 1.048

Old boots = 1.048 - spot on
Muntons 1.060 - even further out

Conclusion

Old boots one is actually not only pretty much spot on but also accurate up the scale. The Muntons is not only more out to start with but is even further out as you go up the scale so would need a further calculation by way of graph to correct. ( cannot be arsed with all that! )