Hydrometer readings in thicker/whole fruit must

[Whino]

I started a wine w dates. Just going for a gallon and i used a whole back of pitted dates. Dates
28 servings
Each serving 26 g sugar
Whole bag = 728 g sugar

I used a hand blender to blend the dates up and got them pretty small but the mausr ends up being somewhat gelatinous probably because of the insoluble fiber which is 3 g per serving. (Maybe i should use pectic enzyme?).

my goal has been to use about 800 g of sugar per gallon so I can get about 11% abv so the fact this bag came out to 728 seemed fine to me. But my hydrometer reading shows 1.060 which I think it is about 8% potential alcohol which is obviously much lower.

so this brings up the question I’ve had for a while is when you’re using whole fruit in a bucket can you really trust hydrometer reading since a lot of the sugar is trapped within solids or maybe the thickness/viscosity of the must is greater because of the insoluble fiber etc? Or maybe it’s possible that the estimate of sugar on the bag is incorrect for this particular bag?

thanks

 

[Ajmassa]

Always trust the hydrometer- not the paperwork!
I have no experience with dates, but I do know you aren’t wrong in your thought process. When making wine kits with grape packs, the SG level won’t change after adding the grape pack. But after macerating for 24 hrs often will see an increase

Def will want to give it some time to integrate and also strain out the solids of a sample before testing. Dropping right in the date filled bucket now vs a strained sample after 24hrs will probably see a good jump in SG. Then ya could confidently add sugar to your target potential abv.

 

[Whino]

Always trust the hydrometer- not the paperwork!
I have no experience with dates, but I do know you aren’t wrong in your thought process. When making wine kits with grape packs, the SG level won’t change after adding the grape pack. But after macerating for 24 hrs often will see an increase

Def will want to give it some time to integrate and also strain out the solids of a sample before testing. Dropping right in the date filled bucket now vs a strained sample after 24hrs will probably see a good jump in SG. Then ya could confidently add sugar to your target potential abv.

Will do thanks for the suggestion. I’ll report back in about eight hours or so

 

[Whino]

Will do thanks for the suggestion. I’ll report back in about eight hours or so

So I filtered some and took a new reading and its even lower. 1.030
I have to assume since the dates are coarsely diced or chopped about down the raisin size but they don’t dissolve very well so by filtering them out I’m essentially taking the sugar out at this point and that might be why the reading is lower.
And I’m going to guess and say that dates have a unique physical property to them that they are a naturally extremely low water containing fruit and that they have a high amount of soluble fiber it almost seems like they’re dehydrated but they are not.
So maybe compared to something like raisins or other dried fruit it could be possible that dates take longer to release the sugar and might throw off the reading earlier in the process or maybe I just have a low sugar bearing package of dates.
The ferment itself has been going like crazy since two hours after I pitch the east last night so it’s very active.

 

[salcoco]

if you took a reading after fermenting started it is not valid.

 

[Scooter68]

Have you ever had dried dates? They are extremely sweet - naturally and they have a relatively thin and tough skin.

Date are a high sugar content fruit. The reason for the low reading is that the fruit hasn't broken down sufficently to release all the sugar. It's probably too late for this batch but I'd do some serious research before trying another batch. Think of all those chuncks of date as being anywhere from 20 to 30 percent sugar and until that chuck breaks down and releases that sugar you can't get an accurate reading.
This is very different than a fruit like peaches that will turn into almost a pudding when they are crushed or juiced. With peaches it takes about 2-3 days for the must to break down enough to get a good reading. The problem then is that that peaches can spoil while you wait so you have work out an alternate method. Unfortunately that method doesn't work when the fruit is in small chunks that still contain a lot of the sugar.

Go do some research on how to break down dates into a juice - I think that's the only way to find a good solution short of having some research data on the sugar content of the average date.

 

[Whino]

Have you ever had dried dates? They are extremely sweet - naturally and they have a relatively thin and tough skin.

Date are a high sugar content fruit. The reason for the low reading is that the fruit hasn't broken down sufficently to release all the sugar. It's probably too late for this batch but I'd do some serious research before trying another batch. Think of all those chuncks of date as being anywhere from 20 to 30 percent sugar and until that chuck breaks down and releases that sugar you can't get an accurate reading.
This is very different than a fruit like peaches that will turn into almost a pudding when they are crushed or juiced. With peaches it takes about 2-3 days for the must to break down enough to get a good reading. The problem then is that that peaches can spoil while you wait so you have work out an alternate method. Unfortunately that method doesn't work when the fruit is in small chunks that still contain a lot of the sugar.

Go do some research on how to break down dates into a juice - I think that's the only way to find a good solution short of having some research data on the sugar content of the average date.

Yea that’s kind of what I figured. Maybe next time I’ll put them in a blendtec blender with some hot tea to completely pulverize and puree them.

 

[KCCam]

Keep in mind, specific gravity is not a measure of dissolved sugar, it is a measure of dissolved and suspended solids. Any must that will drop significantly more lees than a "typical" grape fermentation will render any formula / factor / calculator that we normally use for alcohol estimation meaningless, unless you can account for the increased weight and volume of lees from the fruit. As an example, I crushed my recently picked sour cherries by hand, then strained some juice through a flour sifter (not a very fine mesh, but took out all skin and pits). The SG was 1.065. Then I strained that juice through a reusable nylon mesh coffee filter. The SG dropped to 1.040. Then I strained that juice through a paper coffee filter. The SG dropped to 1.033. The difference in using the SG reading from the flour sifter strained juice and the paper coffee filtered juice is a difference between 9.5% ABV and 5%. All samples have the same amount of sugar content, only the amount of suspended solids (pulp) changed. As another example, you could raise the SG of your must significantly by adding salt, but obviously that would not increase the ABV.

 

[Whino]

Keep in mind, specific gravity is not a measure of dissolved sugar, it is a measure of dissolved and suspended solids. Any must that will drop significantly more lees than a "typical" grape fermentation will render any formula / factor / calculator that we normally use for alcohol estimation meaningless, unless you can account for the increased weight and volume of lees from the fruit. As an example, I crushed my recently picked sour cherries by hand, then strained some juice through a flour sifter (not a very fine mesh, but took out all skin and pits). The SG was 1.065. Then I strained that juice through a reusable nylon mesh coffee filter. The SG dropped to 1.040. Then I strained that juice through a paper coffee filter. The SG dropped to 1.033. The difference in using the SG reading from the flour sifter strained juice and the paper coffee filtered juice is a difference between 9.5% ABV and 5%. All samples have the same amount of sugar content, only the amount of suspended solids (pulp) changed. As another example, you could raise the SG of your must significantly by adding salt, but obviously that would not increase the ABV.

Ahhhh very good point. So is there anything to be done then with various fruit musts like this or perhaps using a refractometer or something else? And for the record I’m not that concerned with knowing the exact ABV but rather I just like being able to do it correctly and also be able to know when the ferment is done using the hydrometer.

 

[Scooter68]

Keep in mind a key to an even semi-accurate reading is understanding if all the free sugar is released so that it can be measured. Now with some fruits this just isn't going to be an over-night thing. Like your chopped dates as you orginally posted about. Regardless of how much straining you do if the fruit bits strained out are holding back some sugars, then your SG isn't reading isn't going to be accurate other than to tell you how much sugar is currently measured in that 'particle free' liquid. I wish I could tell you how long or the fastest process to free up all that sugar for measuring. THAT is the key you need. Steaming, crushing, soaking etc. That's probably what you need to find - how to release that sugar.

 

[Johnd]

Goodness, do what we are all supposed to be doing to get an appropriate sample of our grapes to measure.
1. Take a 2 cup sample after stirring the must to make sure it’s a representative sample
2. Put the sample into a blender and blend until it’s very well mixed
3. Pour the sample through cheesecloth, or a towel to remove solids, and into a vessel of your choice
4. Use the juice you’ve acquired to perform your test on

This is the procedure for testing grapes so that we can adjust BRIX and acid before AF, it works just as well for fruit.