Need help with itasca grape wine making

[wood1954]

I harvested my itasca grapes today. I didn’t wait for them to all turn golden because I was seeing some rot. The ph is 3.26 and the SG is 1.095. The flesh of these grapes are very thick and gelatinous. They also have 4 seeds in each berry and average size is pretty small. After crushing and destemming the grapes I tried to press them and got very little juice. So right now I sulfited and added pectin enzyme. I’m hoping the enzyme will help extract more juice. Any body have experience with grapes like this? I really don’t want to ferment on the skin for very long. Part of the problem is my low pressure press which works fine for fermented reds but not so good in this application.

 

[ChuckD]

I harvested my itasca grapes today. I didn’t wait for them to all turn golden because I was seeing some rot. The ph is 3.26 and the SG is 1.095. The flesh of these grapes are very thick and gelatinous. They also have 4 seeds in each berry and average size is pretty small. After crushing and destemming the grapes I tried to press them and got very little juice. So right now I sulfited and added pectin enzyme. I’m hoping the enzyme will help extract more juice. Any body have experience with grapes like this? I really don’t want to ferment on the skin for very long. Part of the problem is my low pressure press which works fine for fermented reds but not so good in this application.

My Brianna were like that too. But they were picked at 18 Brix to save them from the birds. I only had one vine. I froze them so hopefully that helps extract juice.

 

[wood1954]

After 24 hours I pressed the grapes with my newly modified press. Out of 125 lbs of grapes I only got about 4.5 gallons of juice. It does taste good so there’s that.
Here’s my press operation

 

[Rice_Guy]

My yield was 76% (destemer 17.85 & press 13.6Kg)
Gravity 1.094 (last year 1.102)
ph 3.33 (3.30 in 23)
TA 0.98%. (0.57 in 23 ~> a hot & dry year)

As a variety I really like Itasca. After last year I was wondering about picking earlier. The juice has spent a week in a fridge to pull down tartrates and should have yeast tonight.

Briana 77% yield

 

[wood1954]

How do you press the grapes?

 

[Rice_Guy]

Tried out new parts for an old press.
View attachment 94518
I like stainless and plastic for cleanability, the old collection tray was wood showing rot, basket and press plates were OK but why not go all the way with SS,

View attachment 94519
the screw needs to get cleaned, it was dropping dirt/ greasy flakes, and the stand ought to be strengthened, ,,,,, stuff one doesn’t realize till trying it.

Before getting this from someone in the vinters club I was using a six inch diameter basket plus mix process. With that the yield was in the low 80’s.
Drumlin Ridge winery (where you pick up juice buckets) with a commercial hydro press that cycles: fill > pressure > relax and rotate > pressure > relax > etc, will also get to the 80’s.
There is a lot of gain by mixing our pulp, if you need more yield.

 

[wood1954]

I’m thinking about buying a small bladder press , my homemade press works ok for reds but just doesn’t do justice to unfermented fruit. If I could get 80% that would double my yield.

 

[Rice_Guy]

Are you coming for juice pickup? It is a good chance to look at the winery’s press and talk to the owner about how press cycles operate. There are club folks picking grapes and if you have specifics I could ask.
Generalizations
* time is required, especially on a static press. Mixing reduces the gradient so time is less important, rice hulls create channels which speeds expression.
* for many country wines freezing is more useful than time
* a thin dimension is faster, the magic on bladder presses is the path of travel decreases
* not all grapes are equal, or so I hear when asking.
* more force is useful but reaches a point where there isn’t much gain. With apple low pressure at the start is helpful

 

[wood1954]

No, I’m not getting any juice this fall I’m running out of room.
When I used to go to Mitchell vineyard they had a bladder press for whites that pressed really fast, the small one I’m looking at would probably take a while.

 

[Rice_Guy]

Every once in a while a yield number shows up. Today I was looking at a salt reduction article that used grape pomace (industry left overs) as a flavor enhancement which is effective in copying salty flavor.

From an easy to find ingredient point of view, 20 to 25% of commercial grape winds up in this stream.