og and fg

[stevepostie]

If i got a reading of 1.046 as an OG at 26 degrees c. What percent will my cider be if i manage to achieve an FG of 998 at 24 degrees c. Maths is not my strong point cheers. Also when i get to bottling the cider and adding half level teaspoon of sugar in eah bottle, will the percentage of alcohol remain the same two weeks later.

[Mogwyth]

Of the top of my head around 4.4%abv and it depends what size bottles but yes it will go up a bit.

Cheers

Bill

[mctoon]

I thought about 6.2. do you not take one from the other and divide by 7.5ish

[stevepostie]

Thank you to you both from reading various websites i got it to 6.3% but apparantley the hydrometers norm is at 15 degrees c. As my OG was done at 26degrees c it compliacates the calculation, apparantley The brew kit said it should be about 7%, lets hope I can get it lower than 998 eh! As long as it tastes good and is 5%+ i dont care.
Thanks for yesterdays advice regarding the bottles Mctoon.

[Mogwyth]

should have been 6.4 sorry, that will teach me to check my posts before hitting submit

Bill

[stevepostie]

should have been 6.4 sorry, that will teach me to check my posts before hitting submit

Bill

no problem. That sounds better to me,cheers

[pauljmuk]

yep, a calibrated temperature, you divide by ( and sources differ on this wildy) between 7.5 and 7.75. There are tables online that give you temperature adjustments if you want to be super precise, but to be honest, I find that the minute you put in bottles with priming sugar, and what is undoubtedly and unknown quantity of live yeast per bottle, you cannot be absolutely sure of bottled ABV.

For recipe priming sugar volume perhaps add 0.5% to the ABV?

[stevepostie]

yep, a calibrated temperature, you divide by ( and sources differ on this wildy) between 7.5 and 7.75. There are tables online that give you temperature adjustments if you want to be super precise, but to be honest, I find that the minute you put in bottles with priming sugar, and what is undoubtedly and unknown quantity of live yeast per bottle, you cannot be absolutely sure of bottled ABV.

For recipe priming sugar volume perhaps add 0.5% to the ABV?

Thanks for the help.

[vacant]

For recipe priming sugar volume perhaps add 0.5% to the ABV?

Probably nearer half that e.g. easy example of 100g sugar theorectically adds 0.33%. I use the Inland revenue factors 0.129 or 0.130.

So:
(OG - FG) * [factor]
might be (1045 - 1010) = 35 * [factor]
"35" means I use a factor of 0.129
35 * 0.129 = 4.5%
then add around 85g priming sugar (around 0.23% theoretically, so only assume plus 0.2% in real life.
Therefore my estimate at drinking time would be 4.7%.

[stevepostie]

For recipe priming sugar volume perhaps add 0.5% to the ABV?

Probably nearer half that e.g. easy example of 100g sugar theorectically adds 0.33%. I use the Inland revenue factors 0.129 or 0.130.

So:
(OG - FG) * [factor]
might be (1045 - 1010) = 35 * [factor]
"35" means I use a factor of 0.129
35 * 0.129 = 4.5%
then add around 85g priming sugar (around 0.23% theoretically, so only assume plus 0.2% in real life.
Therefore my estimate at drinking time would be 4.7%.

stevepostie> fetches can of strongbow super from fridge and stares at screen blankly "well this serves me right for asking the question" Thanks for answering it for me though. Although it would take me a while to get me head round it.

[stevepostie]

Great I just found the calculator that the site admin put on. You just put the temp in and it tells you what the difference is. Wish I'd found this earlier.

[Lillywhite]

Decent calculator here:-

http://www.rooftopbrew.net/abv.php

[trucker5774]

I use the same calculations to work out the ABV.....OG - FG divided by 7.45 = ABV or OG - FG x 0.129 = ABV

My hydrometer is calibrated at 20C. at 25C it is plus 0.001 at 30C it is plus 0.003 at 35C it is plus 0.004 It works out to very similar differences with each 5C drop below 20C............So for me at normal measuring time (just before pitching the yeast) It close enough!

The calculator on rooftopbrew is very handy!