How to take the SG of thick must.

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I have been increasing the amount of fruit used in my wines to increase the flavor, 6+ pounds/gallon. I have frozen the fruit (plums, peaches, pears, apricots) and then mixed with sugar for 24 hrs while thawing to draw out the juices. Then I try to measure the amount of juice released and top up the volume with water. In general, I have 1/3 juice, 2/3 water and all the remaining pulp from the fruit in the bag. I am trying to take a hydrometer reading before adding the yeast, but with the amount of fruit pulp from this type of fruit extracted through the bag into the must, how do you get a semi-accurate SG reading? These fruits make a very thick must and I know the density will affect the reading.
 
When I have a thicker must, especially after having used pectic enzyme, I’ll use a refractometer to check the initial SG. Prior to yeast changing sugar to alcohol, you should get a pretty accurate reading. After fermentation begins, and prior to a 1/3 drop, you should be able to get enough of a decent reading using a hydrometer to know when you’re close to the 1/3 mark. It should get easier to use a hydrometer as the fermentation progresses.
 
If you have a large open top of your primary vat (i.e. bucket, or similar) it is typical to use a graduated cylinder. Use a clean pot to get some must (a smallish stainless steel one is ideal). I often also push the pot down the side of the vat, and let mostly juice flow in only. Separate the juice from the pulp using a strainer. Even a thick pulp will eventually drip out juice only (but you may need to take small samples and clean the strainer a lot between samples). Put the pulp free juice into a graduated cylinder, then put in your hydrometer. Once done, return juice and pulp to the vat.

I personally use a plastic graduated cylinder as I would most likely break a glass one.

If you can not get a must sample to strain, then what @David Violante said. And there are online calculators to correct and adjust for refractometer errors as the must starts to ferment.
 
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* the hydrometer is measuring the density of the free liquid. If I have too much dissolved in the juice to have a hydrometer float up and down I do a 50% dilution in distilled water.
* the suggestions about collecting a clean sample work. One not mentioned is that if one is generating lab samples a reusable coffee filter works well, it may blind but gentle stirring gets the pulp off the screen and lets the liquid go through again.
* From your original post, you have a poorly defined mix of solids that have some sugar and liquid that has some sugar. You have no idea what the percent solids is, ,,, you can not get a legal for food labels accurate reading. In the scheme of things for home wine being off on finished ABV by 1% is good enough. If I had to have a reading that was legal I would sample and then grind in a blender to create a slurry and run lab testing on that.
* My experience is that if I weigh everything going in, a calculator on the web will give basically the same answer as the lab test. ,,,, It is nice to kinda know the answer on a 1000 gallon tank before starting,, ,,,instead of waiting for the lab answer.
 
When I have a thicker must, especially after having used pectic enzyme, I’ll use a refractometer to check the initial SG. Prior to yeast changing sugar to alcohol, you should get a pretty accurate reading. After fermentation begins, and prior to a 1/3 drop, you should be able to get enough of a decent reading using a hydrometer to know when you’re close to the 1/3 mark. It should get easier to use a hydrometer as the fermentation progresses.
Dense liquid doesn't affect the refractometer reading?
 
Most of us have or will experience thick musts that can certainly be challenging.

For my part, I line my bucket with a brew bag and take samples between the bag and bucket, the bag acting as a filter. It's simple and works for me.
The fruit is in the bag, but the pulp leaches out into the must with these types of fruit. Do you have an additional bag lining the bucket also?
 
* the hydrometer is measuring the density of the free liquid. If I have too much dissolved in the juice to have a hydrometer float up and down I do a 50% dilution in distilled water.
* the suggestions about collecting a clean sample work. One not mentioned is that if one is generating lab samples a reusable coffee filter works well, it may blind but gentle stirring gets the pulp off the screen and lets the liquid go through again.
* From your original post, you have a poorly defined mix of solids that have some sugar and liquid that has some sugar. You have no idea what the percent solids is, ,,, you can not get a legal for food labels accurate reading. In the scheme of things for home wine being off on finished ABV by 1% is good enough. If I had to have a reading that was legal I would sample and then grind in a blender to create a slurry and run lab testing on that.
* My experience is that if I weigh everything going in, a calculator on the web will give basically the same answer as the lab test. ,,,, It is nice to kinda know the answer on a 1000 gallon tank before starting,, ,,,instead of waiting for the lab answer.
Where do I find this calculator? Does it have a determination of the sugar amount from the fruit? and then I add it to what the SG of the amount of sugar I added should be?
 
Can't say for sure but they fit 5 and 6 gallon buckets easily.
The description says the bag will fit containers up to 17" in diameter, and my LD Carlson 7.9 primary is 14" across, so it's a fit.

@Peggy Billingsley, the weave of this one is good, but it's really big for wrapping around the jig.
 
Dense liquid doesn't affect the refractometer reading?
Yes it does. But for a refractometer you only need a few drops of wine, so it is easy to strain or filter that amount. Sometimes after stirring my wine in primary, I let a few drops from my spoon fall on the refractometer. Usually when I do it that way, I can avoid getting any of the fruit bits on the refractometer.
 
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