False bottom for basket press

[E.E.B.]

Hi everyone!

I'm in the middle of reading Smith's Postmodern Winemaking - an interesting book... Meanwhile, the only thing I can adopt from there as a home winemaker is what he writes about a basket press, Smith argues that the main drain of the press should be from the bottom and not from the sides, he explains that the new metal-bottom presses prevent the drain from the bottom (the wooden bottom has leaks) and this reduces the efficiency of the press. I think I agree with him - when I press with a basket press I get a "cake" that is very wet in the center and dry towrd the edges, which means that a lot of wine is trapped inside the cake.

To solve the problem, I thought about placing a perforated stainless steel or wood mesh at the bottom of the press with some kind of elevation creating a false bottom, and thus create the possibility of drainage from the bottom.

The press i use is this one:

Anyone have an idea how to apply it in practice - which material to make that bottom from?, how to create an elevation for it without affecting the strength of the bottom?, in what size will the holes be? etc. Has anyone experimented with this?

 

[balatonwine]

I have a wood press. A lot of juice flows down the side of the press to the bottom with little actually coming out the sides. See this video clip:



Not sure what is preventing the juice in your press from escaping from the base of the basket. But if there are no areas of juice escape, then maybe simply cutting some escape cuts into the base with an angle grinder would be the easiest solution rather than trying to add some type of plate at the base.

 

[distancerunner]

Balaton's observations are correct. Most of the wine or juice comes out from the bottom. Very little escapes from between the slats. Especially if you line the basket with nylon mesh.

Someone on this forum suggested purchasing some inexpensive HDPE cutting board(s) for use as a false bottom. Size the boards to fit the interior diameter of the basket. Bore many holes in the board. Place on the bottom of the press. Load, press, repeat.

Sounds good on paper. But is it necessary? Give it a try and post your results.

Is the surface of the blocks over the skins have a gap near the center post? Have you tried rice hulls mixed in with the skins to create channels for the wine to move to the outside of the press?

 

[Rice_Guy]

* I like stainless but like plastic just about as much. (found SS on Craig’s list) a 12 inch PVC pipe works, burst is less than 500 lb, I might try a five gallon pail as a first and if concerned wind SS wire around it to get burst over 1000 lbs. ,,, It will work.
Another trick, I save the mesh from delivery pizza to create drainage layer (bottom) and I have kitchen cutting board to make a push surface and heated/ reformed PE to make a slip surface on the acme screwView attachment 102605

There are a number of food grade plastics which have perforations, ex I use a 6” coffee basket which I cut down. If you want stainless there are fairly large perforated steamers and baking plates which could be cut to a target shape. I like the expanded plastic as in the photo above. Practically looking at it no reason not to make a round out 1/4” of oak or oak slats. I like the concept of a cone inside the press baskets but the closest I have come to a fabrication is the cone shape of a Bundt pan. I observe that the base of basket Stays wet.

 

[E.E.B.]

My basket diameter is 25 cm (9.84"), what do you think will fit as a false bottom? also, when you make such a bottom don't you have to make some space between that bottom and and the bottom of the press to allow juice/wine to escape? if so, how can you do that without weakening the bottom resistance to the pressure above?

 

[balatonwine]

maybe simply cutting some escape cuts into the base with an angle grinder would be the easiest solution rather than trying to add some type of plate at the base.

Quoting myself as this discussion is still about a "false bottom" as if it were a plate. There is no need for a false bottom "plate" (in fact it may be more a problem). What is needed is a horizontal juice escape route at the base. If you do not want to cut into your press basket, then you can simply add such space easily with a bit of oak or beech hard wood. You can simply add long wood stays to the base of your press, and radiate them from your press's main horizontal shaft. Think of it as adding wood staves like spokes of old time wheel, then you may get it. Then place your basket on them and press. This will allow your wine to flow our freely from the base.

 

[BarrelMonkey]

If you do not want to cut into your press basket, then you can simply add such space easily with a bit of oak or beech hard wood. You can simply add long wood stays to the base of your press, and radiate them from your press's main horizontal shaft.

This is probably also a better option for those of us with metal press baskets

 

[wood1954]

Hi everyone!

I'm in the middle of reading Smith's Postmodern Winemaking - an interesting book... Meanwhile, the only thing I can adopt from there as a home winemaker is what he writes about a basket press, Smith argues that the main drain of the press should be from the bottom and not from the sides, he explains that the new metal-bottom presses prevent the drain from the bottom (the wooden bottom has leaks) and this reduces the efficiency of the press. I think I agree with him - when I press with a basket press I get a "cake" that is very wet in the center and dry towrd the edges, which means that a lot of wine is trapped inside the cake.

To solve the problem, I thought about placing a perforated stainless steel or wood mesh at the bottom of the press with some kind of elevation creating a false bottom, and thus create the possibility of drainage from the bottom.

The press i use is this one:
View attachment 102975
Anyone have an idea how to apply it in practice - which material to make that bottom from?, how to create an elevation for it without affecting the strength of the bottom?, in what size will the holes be? etc. Has anyone experimented with this?

I just finished reading that book, unfortunately it doesn’t apply very much to Marquette grapes which are very different than vinifera grapes. He goes into so2 and red wines quite a bit. I may use less so2 now, seeing as it isn’t really all that effective in red wines. Definitely have to read the book again and take notes as I read.

 

[Rice_Guy]

25 mm is easy to make and even find in stainless.

ex. 8mm sheet, 1.5mm perforated, 26cm round with several hole sizes. I also like plastic since it is easy to fabricate.
The spacer below isn’t really necessary unless your base deforms like a silicone.

The poly mesh is enough for a torturous channel. Juice is a liquid and will flow from high to low. I use spacers to keep the bottom from sitting in juice, NOT to improve drainage.
As @balatonwine
said wood would work, you have a lot of choices in a 25mm size. BUT a 25cm would need to be ordered, perforated stainless is on Amazon.


With a flat you may see your press basket floats and the press bag crawls between the basket and spacer.

 

[E.E.B.]

I really don't

25 mm is easy to make and even find in stainless.
View attachment 103186
ex. 8mm sheet, 1.5mm perforated, 26cm round with several hole sizes. I also like plastic since it is easy to fabricate.
The spacer below isn’t really necessary unless your base deforms like a silicone.
View attachment 103188
The poly mesh is enough for a torturous channel. Juice is a liquid and will flow from high to low. I use spacers to keep the bottom from sitting in juice, NOT to improve drainage.
As @balatonwine
said wood would work, you have a lot of choices in a 25mm size. BUT a 25cm would need to be ordered, perforated stainless is on Amazon.


With a flat you may see your press basket floats and the press bag crawls between the basket and spacer.

I really don't understand, if the perforated bottom sit right on the press' bottom, how can juice drain over it, the pressure will attach it to the press bottom and no liquide will be able to escape through the holes. I probably missing something, can you explain pls?

 

[Rice_Guy]

The quick answer is that the pores/ cells that the juice is escaping from have smaller channels than the flatness between a metal plate and the base of your press.

First; Juice (or water) will have a tendency to flow an area of high pressure to an area with low pressure, much the same as if it was in a pump.
The pulp inside the basket has pressure on it, as an estimate say 200 psig average. A press just pumped up will have a higher pressure, as an estimate sat 1000 psig. This is enough to cause cells to rupture and flow so they start to fill voids inside the press. (but there still are voids as between skin and cell contents) Juice (or water) is smaller and will preferentially fill the voids. As @balatonwine notes in his video the material inside the press relaxes, the relaxation is partly liquid flowing out of the press basket and partly fruit pulp deforming. All surfaces will weep juice, the rate of weeping is proportional to the back pressure. Yes the top and bottom are solid and will slow but not completely stop flow.

To your concern; The machining of the cast base of a press is not perfectly flat, juice will fill the small voids. On sheet grade stainless there are burrs from where the die went through, juice will fill the small voids between any perforated plate and the press base. In my situation with a plastic mesh juice fills the .5mm void.
Yes, ,, The grapes have the ability to deform and will tend to act as a plug, ,,, conform to the shape of void. This slows the rate at which juice weeps. How bad this is is a function of the fruit. An extremely mature fruit has softer cells and will deform/ plug voids faster. In a commercial press this is answered by gentle pressing followed by a mixing cycle. A little higher psig cycle followed by another mixing cycle. Dry pulp does not deform as well.

Everything in the press is a rate of change function. Rate the pulp reforms. Rate the cells rupture and leak juice. Rate the juice travels between cells. Rate it flows on the base of the press etc. ,,, Press efficiency is also a function of distance. …. A smaller diameter/ distance is more efficient.

 

[justsgm]

I always had a problem with the dry edges and wet center of the pressed cake. Then I discovered rice hulls and I am amazed at how well they work. Sprinkle the hulls in while filling the basket and you get a nice even press with no explosions and a solid cake every time. Rice hulls are only cellulose and do not impart any flavor to the wine that I can tell. They are a godsend.

 

[E.E.B.]

I always had a problem with the dry edges and wet center of the pressed cake. Then I discovered rice hulls and I am amazed at how well they work. Sprinkle the hulls in while filling the basket and you get a nice even press with no explosions and a solid cake every time. Rice hulls are only cellulose and do not impart any flavor to the wine that I can tell. They are a godsend.

I actually could never find Rice hulls for sale here in Israel.

 

[balatonwine]

I always had a problem with the dry edges and wet center of the pressed cake.

Interesting.

I never noticed any difference myself.

Have you actually measured this with an instrument? How did you measure "wetness"? What tools and parameters used to make the reading? What type of press are you using? What was your press pressure? What types of grapes were you pressing? Crushed or not? Stems or not? Etc, etc. etc....

That is, do you have empirical fact based data from actual measurements? Anecdotal data alone is not really useful.... in fact is rather useless.....

I do have a moisture meter. Maybe this year I will test my pressed cake. Just to see....

 

[Rice_Guy]

I actually could never find Rice hulls for sale here in Israel.

Parboiled rice hulls are the chaff from rice which has been cooked/ clean flavor. Hulls are very cheap. If I was looking for a similar material I would take the chaff from what ever grain is in Israel.

 

[balatonwine]

Parboiled rice hulls are the chaff from rice which has been cooked/ clean flavor. Hulls are very cheap. If I was looking for a similar material I would take the chaff from what ever grain is in Israel.

Using any random chaff may make it impossible to label the wine "gluten free"...

Side note: Yes I know by the time the wine if finished, gluten content is basically a non-issue. But that is a technical approach. People's perception, and marketing often are in some weird unpredictable, multidimensional tesseract that defies logic or facts ..... Sadly.

 

[balatonwine]

25 mm is easy to make and even find in stainless.

ex. 8mm sheet, 1.5mm perforated, 26cm round with several hole sizes. I also like plastic since it is easy to fabricate.

Easy to fabricate? That base plate with all those holes? Hm....

Not convinced. Unless you have a lot of tools or a machine shop.

What is easy is to do as I said... lay some wood planks at the bottom. Anyone with a hand saw can fit them to purpose and do that.

 

[Sage]

Cut the bottom out of a trash can to fit your press. It's already ridged, drill holes in it and place slats under it to provide a drain chanel.