Blackberry must SG

[Redbird1]

I'm trying my hand at making wine from fruit and when I took a gravity reading of my blackberry must, it was 1.020. That struck me as low, but I'm not sure why. Is that a reasonable number? I'm trying to figure out how much sugar to add and want to make sure I do that part right.

Thanks!

 

[Stressbaby]

That does seem a little low. Mine have been closer to 1.040.

Can you give some more detail? How much fruit, what size batch, did you crush it already, etc.

 

[Scooter68]

Doesn't just depend on how sweet the blackberries are? Picked early before fully ripe the berries look ripe but are tart and low on sugar. Good news is that it doesn't take long for the sugar in the berries to register once they are crushed. I usually aim for a SG of 1.085 approx before I add my yeast. That should yield an ABV of 12.47% when fermented dry to .990. Allowing for topping off with water over all of 1-2 cups per gallon and you should still have a solid wine. ( I know there is an aversion to adding water but I just don't like adding another wine/flavor to my fruit wines. ) I prefer to use more fruit/gallon and and water to replace volume lost to lees. That way my label is accurate - "100% Wild Blackberry Wine"

 

[Redbird1]

That does seem a little low. Mine have been closer to 1.040.

Can you give some more detail? How much fruit, what size batch, did you crush it already, etc.

I didn't get to weigh them since they had already thawed quite a bit and a couple of the bags were dripping, but it was 3 1-gallon ziploc bags and 1 quart size bag. Rough estimate of 12-14 lbs of fruit maybe. They were quite ripe and fairly large. I ate lots while I was picking them.

I used a new fermenter that I hadn't marked yet, but I'd estimate about one and a half gallons of must. Maybe a little less. I already had crushed the berries and took the reading right before adding the pectic enzyme and kmeta.

Based on everything I've read from a general perspective if the sugar was low, I would have expected a higher volume and 1 1/2 gallons from 12-14 lbs. seem low.

 

[Scooter68]

"Based on everything I've read from a general perspective if the sugar was low, I would have expected a higher volume and 1 1/2 gallons from 12-14 lbs. seem low."

Depends on how much you had in each bag. We normally put about 2-3 lbs per 1 gallon bag.

 

[Redbird1]

Well that might explain it. The bags were pretty well stuffed, but maybe they didn't have as much as I thought. I was moving them late at night after a long day of working outside, so maybe my internal scale was off.

 

[newBendOrfanatic]

The 1.5 gallons is about right for 12.5 to 13 pounds of berries at a 1.02 sg.

 

[Redbird1]

The 1.5 gallons is about right for 12.5 to 13 pounds of berries at a 1.02 sg.

Awesome. Thanks for the info. Do you have some sort of reference document or just from personal experience?

 

[Scooter68]

The 1.5 gallons is about right for 12.5 to 13 pounds of berries at a 1.02 sg.

I had 8 lbs of Blueberries and that was just about 2 cups shy of a gallon.

 

[newBendOrfanatic]

Awesome. Thanks for the info. Do you have some sort of reference document or just from personal experience?

1.02 x 1.5 x 8.3. The 8.3 depends on water temperature, but it is close enough for this type of approximation.

 

[Stressbaby]

I get about 4.5# per gallon bag. So 14-15# is about right. You could get 1.5 gallons from that. But this wouldn't affect the SG either way.

You say the berries were quite ripe. If so, that SG still seems low to me. I would double check it if you haven't already.

Also, have you checked pH? My blackberry wines have been 2.79-2.99 range, and all have required a bit of a pH adjustment.

 

[Redbird1]

1.02 x 1.5 x 8.3. The 8.3 depends on water temperature, but it is close enough for this type of approximation.

Thanks. I've never seen that before. It does seem like the SG has very little contribution to the calculation, so I would need to be much more precise in my measurements and with the 8.3 number.

 

[Redbird1]

I get about 4.5# per gallon bag. So 14-15# is about right. You could get 1.5 gallons from that. But this wouldn't affect the SG either way.

You say the berries were quite ripe. If so, that SG still seems low to me. I would double check it if you haven't already.

Also, have you checked pH? My blackberry wines have been 2.79-2.99 range, and all have required a bit of a pH adjustment.

I trust my measurement, but I'll double check the calibration of my hydrometer. It has been a little wonky in the past. In has been up to .004 off at times. Not a big difference, but still something.

I have a pH meter, but haven't tested the must yet. It is a cheapo one and I've read that those aren't super accurate. I'm wary about making adjustments based on it.

Side note: The whole front half of the house smells like blackberries. It is awesome.

 

[Scooter68]

I have a $20.00 pH meter - does a great job. Calibration checks perodically show a little drift but nothing serious. If it's off by .05 that's still not a deal breaker Never heard of a wine spoiling or being considered bad because it was actually pH 3.55 instead of 3.50. Most of the entry level ones are sold as being accurate to .01 or .05 in either case that's good enough for wine making. Just take care of it rinse and dry and check for residue build up in the nooks and crannies of it.

 

[evansmedine]

The last few batches I made I used 15# of frozen berries for a five gallon batch. SG to start 1.080 to 1.090. ABV calculates to 12.8 to13.0. It is my favorite.

 

[Scooter68]

The last few batches I made I used 15# of frozen berries for a five gallon batch. SG to start 1.080 to 1.090. ABV calculates to 12.8 to13.0. It is my favorite.

Was that your SG without any sugar added to the blackberries? That sound pretty high for blackberries without any additional sugar.