Bladder Press Blowouts

[GreginND]

Hi folks.

I’m looking for some advice. When pressing fresh grapes using my Lancman 250 l bladder press, I often get grapes slipping out the bottom of the basket in a glorious geyser of must. This happens most with white grapes with lots of labrusca lineage as the grapes are juicy and the skins quite slippery. I do use the green mesh bag inside. But grapes always blow out anyway. It makes a big mess and if you are in the way, you end up covered in grapes.

Does anyone else have this problem? What have you done to prevent the blowouts?

Thanks.

 

[stickman]

Have you tried adding rice hulls while filling the press? I don't have direct experience, but have seen several wineries using rice hulls during pressing with North American varieties. The hulls provide channels to allow the juice to flow more freely.

 

[Johny99]

I have the same press and never had the problem. I only have done vinifera and apples tho. Are you getting the basket well seated and the top screw down good? If so, the gap at the bottom is really small. I would think something must deform to let must out. Juice squirt yes! I too use the mesh bag inside.

A couple thoughts ftiw. Is the basket lifting as you fill? Had that problem once when a helper pressed the grapes, white, to squeeze some more in. Or, does it always happen in the same spot on basket or bottom pan? Something not flat perhaps?

 

[balatonwine]

When does blowout occur? If not immediate, do you have a pressure regulator on your press? In not, consider a pressure regulator (or one with smaller increments if you have one now) and adjust it so you can be in more control of the water pressure into the bladder, increase it in steps (only increase it as juice output slows), and take it slowly. Stop when blowout seems impending. Bladder presses were designed for Vinifera. So I doubt their design is amenable to the characteristics of some American grapes in all cases.

Another option, is use a basket press for your labrusca linage grapes -- a basket press will also allow finer tuned pressing control. You will get less juice, but also should not have a must bath.....

Final option -- just use free run juice. Press is not necessary in all cases, and some believe free run only may make a better wine.

 

[salcoco]

labrusca grapes are referred to as slip skin grapes. that is why I believe they slip out the bottom of your bladder press . once solution is purchase a netting the fits inside the bladder press. you can then place it below the bottom seam to prevent blowout. the other is I seem to recall an enzyme that can be used for slip skin grapes to increase juice I believe scottlabs offers the enzyme. this might help break down the grapes and keep blowouts down.

 

[GreginND]

Thanks everyone. I appreciate all your comments. Yes, we use rice hulls. It doesn't help. The basket is seated and tight. It is those damn labrusca skins. Sometimes they will spurt out before the pressure even gets to 2. I really don't have time for enzymes to work as I need to get them from the crusher directly to the press and I want to avoid as much oxidation of the color as possible.

I am thinking maybe some kind of screen around the bottom inside the press may help. The mesh bag doesn't seem to be helping as it doesn't seem to bend toward the center of the bottom. It just hangs to the bottom and the grapes go under it. The other thing may be to throw stems in the bottom of the press hoping that will catch the grapes up. But I don't want any of the bitterness from them. Hmm, maybe something else?

 

[ibglowin]

Are you you using dry ice?

I really don't have time for enzymes to work as I need to get them from the crusher directly to the press and I want to avoid as much oxidation of the color as possible.

 

[Johny99]

My net “bag” is really a cylinder. Could you suspend it lower, Lettie wrap words the bladder, creating a bit of a cup? If yours is like mine, it would be short at the top by 3-4 inches but maybe the lesser of two evils.

 

[salcoco]

back to Scottlabs.com pg 68 of fermentation handbook refers to a enzyme call Extra Press made specifically for slip skin variety grapes it states"used for improving press ability on hard to press varieties" added when filling the press. does not state any time element should fit in with your problem of time. A phone call may also help in any questions you have.

 

[GreginND]

Are you you using dry ice?

What would I use dry ice for? The grapes are pumped directly from the destemmer into the press. I'm not sure how dry ice could be used here.

 

[ibglowin]

I believe you said you wanted to avoid oxidation as much as possible.

Dry Ice would certainly assist with that after crushing/and pressing into your tank for settling.

What would I use dry ice for? The grapes are pumped directly from the destemmer into the press. I'm not sure how dry ice could be used here.

 

[wxtrendsguy]

Hi Greg, I know this is way late but I used to own that press and the trick is to bring the pressure up slowly...there is no way to rush it. You have to take you time...if memory serves me right it was almost 60 minutes time to get the pressure in the bladder to equal my household water pressure. We would just barely crack open the water and let it fill very slow....by the end of pressing we could open the valve all the way but there is no further flow ....

 

[user 36973]

I have a larger version of these sort of presses and have blow outs at the bottom when either (1) the basket is not screwed tightly to the base or (2) the grapes get under green mesh net inside.

The second is more common. To prevent (2) I flatten the net at the bottom of the basket (which gives me several inches of net curled inside) and try to not disturb that when the must is dumped into the basket.