View Full Version : Measuring OG After Pitching Yeast

07-28-2016, 08:13 AM
I attempted my first cyser yesterday using a recipe I got from an e-book and at the end of the process realized I had forgotten to take an OG reading prior to pitching the yeast. I decided to take one afterwards and got an OG of 1.53, which the hydrometer says is equivalent to about 20% ABV. My question is, did taking the reading after pitching the yeast and adding all the other ingredients throw off the OG to such an extent that it's not useful, or is it still a fairly close approximation?

The recipe I used was as follows:

~1/2 gal. or so apple juice
2-1/2 lbs. clover honey (Stop & Shop brand)
1 packet (5g) Lalvin 71b-1122 yeast
3 green apples cut into 16 slices (frozen)
3/4 tsp DAP
3/4 tsp yeast energizer (the recipe only called nutrient, but I added the energizer on my own)

While I thought I had left sufficient headroom in the 1 gal. glass carboy I used, I awoke this morning to an explosion of must all over the shelf where I stored it from a particularly aggressive fermentation process. Yeesh! I think in the future I'll use a 2-1/2 gal bucket for my primary fermentation and pitch to the carboy for a secondary and long-term storage.

Still learning here, so thanks for any input you can provide.

07-28-2016, 08:54 AM
It shouldn't make any difference when you read it although that seems really high. Maybe the fruit has done something to it.

The bigger bucket will be your friend. Cysers usually do make a good bit more foam than usual. I would get away from DAP and use fermaid-k instead. Or better yet Fermaid-O
DAP can/will leaves a bad aftertaste and can't even be assimilated past 9% ABV. Some will say DAP is fine. It was the go to for ages. I promise once you stop using it you will be glad you did.
I can taste it in everything. Unless of coarse it hasn't been used.

Welcome to the community. Stick around. This is by far the best mead forum on the planet.

07-28-2016, 09:50 AM
It usually takes a couple of hours before the yeast colony reaches its maximum size. Before that the fermentation will be slower. Depending on your yeast and methods taking a reading after the pitch will present an unknown of varying sizes in your ABV equation. If it's like only a couple of hours you can still label your bottle as "approx. x%" where x is an integer. If it's more than a day you can already be a full percent off. However another unknown are the apples.

There's sugar in the apples which will dissolve into your must but which the hydrometer cannot pick up at the beginning since they're still contained in the solid mass of the apple pieces. This means your "real" O.G. will be too low for the actual total sugar contents of your must. These additional sugars of uncertain quantity will ferment too and will present an unknown on your ABV calculation later on as well.

Also, once you got bucket for your primary you never want anything else again :)

07-28-2016, 11:19 AM
Hiya, BlackFriarsMonastery - and welcome.
If we are talking about 1 gallon of must and if that gallon includes about 2.5 lbs of honey and a half gallon of apple juice I would estimate the starting specific gravity to be closer to about 1.120 and not 1.53(0). You are likely to get a gravity reading of close to 1.040 with 1 lb of honey dissolved in water to make a gallon, so 2.5 lbs = 1.100. A gallon of apple juice will have a gravity reading of about 1.040 too, so half a gallon diluted to make a gallon of must will have a gravity of about 1.020. Adding the juice and the honey will give you a reading of about 1.120.
If your reading was 1.53 (usually reads to three places after the point, so 1.530) then I would be more than surprised and I would have to think that there was something wrong with the hydrometer or the reading you took. A reading of 1.530 suggests a must that is as thick as syrup with the potential ABV at spirit level (not anything possible for yeast to survive in, never mind ferment).
If the reading was 1.053 then I think the issue might be that the honey was not adequately dissolved.. If my calculations are reasonably correct then you can expect an ABV of about 15-16 % if all the sugars are successfully fermented. But that said, IMO, a starting gravity of 1.120 is fairly high and this might take a L-O-N-G time to suitably age and lose sharp edges.

07-30-2016, 12:54 AM
Methinks we have a faulty reading! If it's bubbling then you're OK.

07-30-2016, 07:14 AM
Did you add any water, or is your apple juice the only liquid?

I echo my affinity towards primary buckets. It makes cleaning easier, too.

07-30-2016, 08:39 PM
Thanks for all the responses! Great stuff. For clarification, I took the reading within in minutes of adding the yeast to the carboy, so there had been no real fermentation action occurring yet. And the hydrometer was riding pretty high in the must in the test tube. I actually tried it 2-3 times just because the reading seemed really high to me too. I did the spinning thing too and there were few bubbles at the time. And I'm certain it was at the 1.5 level with 3 lines below it to just below the line of meniscus. On the hydrometer it was almost exactly at the line that said 20% ABV. And it was just apple juice and honey, no water.

With that said, it fermented like crazy for 2 days and kept blowing out through the airlock (and made quite a mess on the shelf where I had put it). I poured off a bit each time until it stopped erupting through the airlock. Now it's percolating along fine, but since the volume has been reduced, would it be okay to add more liquid (either apple juice or water) after I rack it to a secondary to bring the volume up to a gallon again?

Thanks again!

07-30-2016, 10:45 PM
Sure,that would be fine

07-31-2016, 10:25 AM
Yes it is OK however, note the gravity right before adding the juice/water and the new gravity after adding it. Write both down. Then in the end you can calculate how much alcohol there is in your must. If you forget to do this now you will not be able to get a calculated ABV in the future.

08-02-2016, 06:32 PM
Okay, this is a bit embarrassing. I actually just looked more closely at the hydrometer and realized the reading I got wasn't 1.53 but rather 1.153. Duh. I had see the 50 reading on the scale and assumed that meant it was at 1.5, but obviously that's not the case as there's a 1.1 reading ahead of it, so it was obvious I should have added the 50 plus the three hash marks to the 1.1 to get 1.153. As I said, duh.

08-02-2016, 08:35 PM
Now that it has been a week, what's the current gravity?

08-04-2016, 02:09 PM

I took a gravity reading and it had reduced to 1.071. What does that tell me? :) And should I take a gravity reading weekly of all my meads? By the way, it tasted really good. There was a potency to it, which probably isn't surprising, but it wasn't overpowering and there was a sweetness to it that was stronger than the alcohol taste.

Thanks for your insights,


08-04-2016, 04:50 PM
Punch in your og (original gravity) and your sg (specific gravity, or in other words, your current gravity) into the gotmead calculator and it'll tell you your current abv - http://gotmead.com/blog/the-mead-calculator

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08-05-2016, 05:40 AM
Ah! Thanks, djsxxx. So with a SG of 1.153 and a current reading of 1.071, I get an ABV of 10.99%. Great! Now I admit I haven't taken temperature readings, which I'll begin doing, so I'm guessing my readings may need a slight tweaking if it's not at the estimated 68F, but for this newb it at least puts me in the ballpark. Thanks again.