Starting And Final Specific Gravity Readings For Wine

Taking Final Specific Gravity ReadingI am in the process of making my first batch of Scuppernong Wine. The SG [specific gravity] at the beginning was 1.116… The process has been going on for about 8 weeks now. The SG now is 1.030… I still see activity. What should the final specific gravity reading be when the wine is complete?

Name: Charles P.
State: South Carolina
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Hello Charles,

To answer your question, you should expect a final specific gravity for wine somewhere between .992 and .996 on your hydrometer.

Your starting specific gravity reading was a little high, so your wine yeast has a lot of work to do. Normally you would want a starting specific gravity between 1.070 and 1.100 for wine. Yours was 1.116. This may be more than the wine yeast can handle.

 

There are two reasons for this:

  1. Shop HydrometersSugar acts as a preservative. If the concentrate of sugar becomes too high, it can actually interfere with the wine yeast from even starting. Your fermentation started, so obviously this is not an issue for this fermentation.
  1. Wine yeast has a limited tolerance to alcohol. As the alcohol level rises in the wine must, the wine yeast finds it harder and harder to ferment, sometimes to the point of not being able to ferment at all. This would be known as a stuck fermentation.

 

Your starting potential alcohol level was between 15% and 16%. A majority of wine yeast will have a hard time fermenting to this level of alcohol.

My guess is that your fermentation will become very slow as it ferments the last few percentage points of sugar. If this is the case, just be patient and give it plenty of time to do its thing. As long as you can see some slight progress, you are okay.

However, depending on the wine yeast you used, the fermentation may not be able to finish at all – a stuck fermentation. If this is the case, you may be forced into a situation to where you need to dilute the wine must with water to cut its alcohol level. This will help the yeast to start up again and finish the fermentation.

Since the starting specific gravity for your wine was so high, I would recommend that you also take a look at the Top 10 Reasons For Fermentation Failure. By doing this you may discover other things that can be done to help the fermentation along and get the final specific gravity for your wine where it needs to be.

Happy Winemaking,
Ed Kraus

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Ed Kraus is a 3rd generation home brewer/winemaker and has been an owner of E. C. Kraus since 1999. He has been helping individuals make better wine and beer for over 25 years.

54 thoughts on “Starting And Final Specific Gravity Readings For Wine

  1. What would happen if I just added a camden tab and potassium sorbate to stop the fermentation at that point? Would it have a more fruity taste because there is residual sugar?

  2. Jan, you have to use something called the Pearson’s Square. It’s a visual math tool that helps you to determine the ratio you need of two liquids to achieve a particular reading. In your case specific, SG with wine must and water to be blended. You can find more on the Pearson’s Square about half way down on this article on blending wines. Hint: think of water as one of the wines being blended: http://www.eckraus.com/wine-making-blending/

  3. Bob, more than half the time this works, but it is far from a guaranteed stop. Most of it has to do with how many yeast cells are still floating in the wine. If it doesn’t work the cost can be great. Your wine could end up fermenting in the bottles; pushing the corks out and making a mess. And worse yet, if the corks don’t give the wine bottles could start exploding. You can find more on this at the following blog post:

    How To Stop A Fermentation
    http://www.eckraus.com/wine-making-stop-fermentation/

  4. Hello
    I have a 6 gallon carboy that I had to restart the fermentation because it seemed to have stopped.
    I used your recommendation on how to restart.
    It has started bubbling again very slow it’s been a 10 days and the specific gravity is still at 1.040 and has not moved.
    Should I see SG movement in that amount of time?

    • Rob, if you are seeing fermentation activity then you should see movement in the hydrometer reading. You can check your hydrometer in water to make sure that you are getting a correct reading. If it is still stuck, take a look at the following article to see if something else could be causing a stuck fermentation.

      Reasons For Stuck Fermentation
      http://www.eckraus.com/wine-making-failure

      • Hello
        I am an avid reader of your blog and am making my third batch of wine with black grapes.
        SG of the juice was 1.040. So I added 850 gms of sugar in 6 litres of the must to get it to 1.090. Fermentation started but after six days I can see no activity. Is it stuck or have I put in too less sugar? I dont have an airlock fitted.

        • Shrabanee, the specific gravity reading shows that you have appropriate amount of sugar in the juice. The first thing that i would do is take a hydrometer reading. You can’t always by looking if there is fermentation activity. If the hydrometer does indicate a stuck fermentation, please take a look at the article posted below on the common cause of a stuck fermentation. Before you can correct the problem you need to know the cause.

          Top Reasons For Fermentation Failure
          https://eckraus.com/wine-making-failure/

          • Hello once again..
            Made strawberry wine for the first time. Started the fermentation process on 5th April 2019. Measured SG on 3rd May 2019 which is showing a reading between 1.000 and 0.990. The airlock has also stopped bubbling. Is everything ok?

      • Hello..
        Made strawberry wine for the first time. Started the fermentation process on 5th April 2019. Measured SG on 3rd May 2019 which is showing a reading between 1.000 and 0.990. The airlock has also stopped bubbling. Is everything ok?

  5. Ed, I started a Cabernet Sauvignon and after adding the yeast the SG registered 70.
    Do I need to add more water to bring it closer to 1.07-1.08?

    • Matthew, knowing the specific gravity that you determine with a wine hydrometer is important to the success of your fermentations and winemaking in general. Without a wine hydrometer, it’s much more difficult to determine the sugar level in your wine must or your wine, thus making it even more difficult to know how your fermentation is progressing and if there are any unexpected adjustments you need to make. Wine making using a hydrometer; monitoring the specific gravity of your must, you’ll be ready when an unexpected change occurs requiring your attention and adjustments, and you’ll be able to determine how much potential alcohol the wine you are creating will be and you can adjust accordingly if need be. The hydrometer reading is the only way to know for sure that the fermentation has completed or if it becomes stuck.

  6. My wine sg was 1050 .the second fermentation is almost finished but it’s stuck at 1028 this is my first batch of wine I need help

  7. Hello! With my first batch of wine, a spiced apple, I also did not realize my SG (1.120) was to high prior to pitching my yeast. Feemintation never ‘took off’ like I’ve.seen it do in beer brewing , but it is happeneing. I am almost a week into my second fermintation, and it’s still going, but barely. If it does stop well before I hit the ideal SG and I need to add water…1) do I need to sterilize the water (boiling or otherwise) before adding 2) should I also add more yeast? Nutrient? Energizer?

    • Dani, you do not need to boil the water. If you are using tap water, all you need to do is let the water sit overnight to let the chlorine dissipate. Adding additional nutrient or energizer might help but adding more yeast is not necessary unless you want to make a yeast starter if it would become stuck. The article below will teach you how to make a starter.

      Yeast Starter
      http://eckraus.com/wine-making-yeast-starter/

  8. After letting my wine sit for two weeks the S.G. is staying at .994. I went on to the next step of degassing and adding kieselsol and chitosan. Is my S.G. supposed to change between now and bottling(2 weeks)? What should S.G. be when you bottle?

    • Steph, yes you do need to add water. A reading of 1.170 extremely high and would more than likely result in a stuck fermentation. You want a reading somewhere between 1.060 and 1.100.

  9. Hello once again..
    Made strawberry wine for the first time. Started the fermentation process on 5th April 2019. Measured SG on 3rd May 2019 which is showing a reading between 1.000 and 0.990. The airlock has also stopped bubbling. Is everything ok?

  10. Mr. Kraus, I crushed 56 cases of Cabernet Savignon grapes from California 6 days ago and am noticing the frothy fermentation is nearing the end; my SG was 1.024 and I am ready to bladder press my grapes in 2 days to put in my stainless steel barrels with a bubbler for the winter; I will rack the wine in about a week from pressing; my question is what is the ideal SG that I should start to press my grapes?
    Gerry

    • Gerry, there is not a certain specific gravity stage that you will press the juice. Typically, when making wine with red grapes you will leave the pulp as part of the fermentation for about 5-7 days before pressing the juice. This process will allow you to draw more color from the red grapes.

    • Brandan, the hydrometer can only read sugar content. It does not read alcohol content at all. What a hydrometer can do is tell you how much sugar was consumed during the fermentation, that in turn, tells you how much alcohol was made. Essentially, 1.000 SG means there is no more sugars to ferment into alcohol. Usually it ends up at .996 or so, same thing.

  11. Is it possible to have an original gravity and a final gravity exactly the same for homemade strawberry wine? I started with 1.024 o.g. and ended with 1.024 f.g. before final racking. I’m very disappointed and perplexed.

    • Pebbles, it is not possible to have the same beginning and ending reading unless there was no fermentation at all. Are you sure that you are getting accurate hydrometer readings? A starting gravity of 1.024 is very low and would have produced only about 2.5 percent alcohol. I would take a look at the article below on how to get accurate readings.

      How To Take Accurate Hydrometer Readings
      https://blog.eckraus.com/taking-hydrometer-readings-wine

  12. My problem may be the opposite of a suck fermentation? On my secondary fermentation, I have slow bubbling in the airlock. When I check with the hydrometer, I get 0.990 or less. When I rack into a new bottle, I get more bubbling on my airlock. A couple of weeks later, I rerack and still get bubbling on the airlock. I spin the hydrometer to remove air bubbles and have rechecked with a friends hydrometer. Am I over concerned with yeast consuming all sugars and eating the dead yeast?

  13. My starting hydrometer reading was 1.025 it went up to 1.030 after adding the yeast. I took it out of the primary bucket when it reached 1.000. It never bubbled and I’m not set to bottle it for another two months. Can you tell me what my current alcohol level is?

    • Lauri, first let me say that unless more sugar was added it is not possible for the specific gravity to go up. If your specific gravity reading was 1.025 to 1.30, that would mean that you would only have 3.5-4 percent alcohol. That is pretty low for wine. Typically you want somewhere between 8-13 percent alcohol.

  14. Making grape raspberry wine – I added water and sugar to the grape/rasp juice for a beginning S.G. of 1.080. After 5 days primary fermentation (today), it is at 1.000 which is where it’s supposed to be when complete. I moved to secondary fermentation with airlock today. Do I need to correct this low reading, and if yes, how? with sugar or water?

    • Sassy, you do not need to do anything but wait for the wine to clear. You just had a very successful fermentation and the fermentation completed quickly. There is nothing wrong with the wine, just proceed as normal.

  15. Just purchased 6 gallons of wine must today and took a S.G. reading of 1.006. Is that even possible? there’s no sugar in this must? I racked it from the bucket to a carboy so it should have been thoroughly mixed. Perhaps I only sampled from the top to test? How do I fix before starting primary fermentation?

    • Joe, if the hydrometer reading is correct, it does indicate that there is very little sugar in the juice. If the reading is correct, you will need to add more sugar to get it within an appropriate range. The general rule of thumb is that one pound of sugar in a 5-gallon batch will raise the potential alcohol by one percent. Your hydrometer will also help you to know how much sugar you need to add.

  16. Hi!!

    First off thank you for keeping up this website, your stuff has been extremely helpful for me over the past few years getting my winemaking skills up! I’m making my second batch of red Zinfandel from grapes this year. My hydrometer is reading at 1.110. I do like a very high alcohol content wine, but I don’t want to risk ruining the batch. I pitched with EC1118 which supposedly is fairly hardy, but again, If it never starts, it won’t matter… Is it worth the risk?

    Thanks!!

  17. Hi
    My first batch of Saskatoon Berry wine. I followed a recipe fairly close found in a published book. I just added the Lalvin yeast 2 days ago. It is working like crazy. I took the SG reading at 1.14. This is really high. Tested the hydrometer and it zeros with water. Should I add water at this point to cut the sugars ?

    • Jim, that is a pretty high starting gravity. I would wait to see if the fermentation stalls before completion before adding any water. If it does become stuck due to too much sugar, you can dilute it with water to get it to finish.

  18. Hi,

    I’m making my first batch of wine for grapes from the garden. My starting point had quite low sugar levels, around 1.045 (7%) I added the required amount of sugar and retested getting a reading of around 12% (1.070). I pitched my yeast and seemed to have a successful first 2 days. On day 2 I took another reading where I got around 6% pot alcohol, I’m now on day 5 where things look like they are coming to a halt. I’m getting a reading of 1.020 and my musk is barley getting a cap on it. Am I on the right track as this seems to have fermented very fast? Now, do I need to wait until it drops to below 1.000 before racking into a demijohn for a second ferment? Once it drops to below 1.000 what is the purpose of a secondary fermentation if there is now no remaining sugars?

    Many thanks!

    • Tyler, it does sound like you are having a very successful fermentation. It is not uncommon for a fermentation to actually complete in as little as a few days to a weeks time. The primary fermentation typically lasts 5-7 days. At that time the specific gravity is usually around 1.020-1.030. At this time, you want to transfer the wine to the secondary fermenter and remove the fruit pulp if any and let the fermentation complete. The fermentation is not complete until the specific gravity reaches .998 or less. Because around 70 percent of the fermentation activity occurs in the primary stage, you will not see as much activity.

      When TO Transfer To Secondary
      https://blog.eckraus.com/when-to-move-wine-to-secondary-fermenter

      • Thank you very much for this.

        I’m currently on day 5 of my wine being in it’s secondary fermenter. I just took a reading and got 1.010 / 1.000 – It has dropped only the slightest amount in 5 days, is this a stuck fermentation? I noticed a few bubbles in the airlock on the first few days but now the liquid is almost lying level. The wine has cleared a little with an inch or so of sediment on the bottom of my demijohn. So my second question is, should I rack my wine off this sediment even though it could be still fermenting?

        If it’s a stuck fermentation, I can’t worm out what the cause would be even after reading your article on a stuck fermentation.

        • Tyler, if the reading is changing, even slowly, it is fermenting. It is normal for the activity to slow down when it is almost complete. You do not need to rack the wine until the fermentation completes, which should be any day now.

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