SG / ABV School Boy Error

[Ciderman62]

I Have 5 batches of cider at various stages of fermentation I made a real newby/schoolboy error on my first two batches by not taking SG readings prior to starting fermenting.

Each batch I have made has a different apple combination therefore not as simple as just averaging out the SG from those I remembered to sample.

As these were the first batches fermentation has all but stopped the latest SG reading was 1.004 and there are no longer bubbles in the airlock although there are still some tiny pin head bubbles visible on the surface.

I will be taking further readings over next few days & once I have three consecutive readings of the same value I will move on to bottling

Given I do not have the starting ABV or sugar content (g/l) is there any way I can calculate / check the finished ABV

 

[VikeMan]

For 27 bucks, you could have it tested.
https://www.whitelabs.com/lab-services-product-detail?id=20&type=PRODUCT
Or, if you have a refractometer as well as a hydrometer, you could estimate it.

 

[DuncB]

@VikeMan
Out of interest how do you estimate abv with a hydrometer and refractometer ( mines digital is that okay).
Just for knowledge not need in my case.
Thanks.

 

[VikeMan]

@VikeMan
Out of interest how do you estimate abv with a hydrometer and refractometer ( mines digital is that okay).
Just for knowledge not need in my case.

Here's one calculator. (There may be others). It basically does the standard refractometer corrections in reverse.

https://www.brewheads.com/refract-getabw.php
ETA: I don't know any reason that it wouldn't work with a digital refractometer.

 

[DuncB]

@VikeMan

Thanks for that I've bookmarked it and will keep it in the " in case of emergency break glass " cupboard.

But it might be useful for that Imperial stout I fermented and then added a couple of kilos of dextrose to, thank you.