PSI required for pressing?

[wildman]

Since building a good grinder my press has been the weak link in my pressing operation. It works good but just isn't capable of the volume I desire. It's time to build a big one. I'm going to use a 20 ton bottle jack and want to make full use of it. Unfortunately I've found almost no info on the pressures involved in the pressing of apples. the only info I've seen is from the cider by rosie blog and she stated that 25psi is what it takes. And while I would trust that and leave some headroom for inaccuracy and not operating the press to its limits (i was thinking of 40-45psi capability) it really would be reassuring to have more than one reference to go by before I finish designing and then building it. Id appreciate any input that could be provided.

 

[gregbathurst]

Andrew Lea recommends 70psi for a 70% yield. He says 35psi gives 65% yield. http://www.cider.org.uk/press.htm so 40-45psi sounds reasonable if you don't worry too much about yield - I find that last bit takes a lot more bother than its worth.

 

[wildman]

That's exactly what I'm looking for. Based on those numbers the footprint might get a little smaller. I also overlook that last little bit of when I'm in full swing pressing mode but also take advantage of an overnight pressing as often as I can. The extra pint to quart in the morning from my little press is always nice. Some short math tells me the new press could have 10x the volume.
I'll plan on the 75psi max. I think it will give me the headroom I want. Thanks Greg I appreciate the response.

 

[gregbathurst]

This year I have pressed about 200gal. I have decided the capacity of the press is very important. My press does about 5gal per pressing so doing 200 gal gets a bit tedious. I would like to do about 12 gal per pressing, even if it meant losing some pressure and efficiency. It wouldn't bother me to lose a bit of juice if I could make the process faster.

Greg

 

[sashurlow]

You could also combine and re-press. I found I got a little bit more by doing that, but not enough to keep doing it.
How do you determine PSI of a press anyway?
Scott

 

[merlotsj]

How do you determine PSI of a press anyway?
Scott

24" x 24" slat plates, 70 psi desired:

24 X 24 = 576 sq. in.

70 * 576 = 40,320 lbs, or about 20 Ton

5 Ton Jack, 70 psi desired:

5 X 2000 = 10,000 lbs

10000 / 70 = 142.86 lbs

square root of 142 = 11.93", or about 12" x 12" slat plates.

 

[wildman]

I hear you there, I pressed 70 gallons 2-3 gallons at a time last yer and its more work than I care to do on my time off. Designing it for a 75psi max would give me ~10 times the volume or more depending on its final height. Being a man that depends on his tools for a living, I wouldn't run it at full pressure.

BTW I just saw a pic of john downie crabs, they look interesting. I haven't seen anything similar around here.
its not often I see crabs that large. How good do they work for you?

 

[wildman]

Dp

 

[wildman]

That's what I got for numbers. 24*24 cheeses, 28*28 slats and a 32*32 collection tray. It will still easily wheel through a common doorway which will also determine how tall it is.

 

[gregbathurst]

BTW I just saw a pic of john downie crabs, they look interesting. I haven't seen anything similar around here.
its not often I see crabs that large. How good do they work for you?

I have one tree of "John Downie" that I planted years ago. The apples are pretty small really but good quality, the birds love them which shows they are good. I wanted to grow lots of ornamental apples so I grew seedlings from JD and planted them all around. Apple trees are not self fertile, so the JD must have crossed with some proper eating apples growing in my orchard, and these seedlings produce crabs that are bigger than JD, fairly tannic but have good SG.

This year my orchard apples were not as ripe as usual due to a heavy crop and cool weather. The SG has been around 1.045 - 1.050 (6.0 - 7.0 baume) when I normally expect 1.055. Normally I am happy to drink cider made from just orchard fruit, a mix of cookers and dessert apples, but this year I am very happy I have the crabs to add a bit of flavour and boost the SG. I have been using 10-15% crabs and that seems to work pretty well. If you're not happy about the quality of your juice it's an excellent way to give it a boost, you don't need to add a lot of crabs, but it's a good idea to test the flavour and SG before using them if you're not sure.

Greg

 

[Rockape66]

Crabapples tend to be self pollenating; being closer to original parent stock. Many orchards have crabs as pollenators for their other crop. The crabs give you a nice balance of tannins/acid to sugars for a much better cider. I just wish I had access to some quality crabs where I live, but I am getting a nice cider with the blend of apples I have available in season. Enjoy your crabs, Mate.

 

[sashurlow]

Sorry to break of of the topic but... I've heard you should have a blend of bittersweet, sweet and sharp. What do crab apples qualify as?
Scott

 

[CidahMastah]

Sorry to break of of the topic but... I've heard you should have a blend of bittersweet, sweet and sharp. What do crab apples qualify as?
Scott

Most should be characterized as a sharp. Keep them as 10-15% or less of your blend. A little goes a long way

 

[wildman]

Depends on the crab. I've seen them all. I look for ones that are bitter and dry tasting without any sour notes. That's the bitter your looking for. I tend to think of things a little different when collecting apples. I place them in desert, cooking, sour and crab categories. I view crabs as an Apple with flavor on steroids. The more you can fit in without wrecking the flavor the more your finished product will taste like apples.

If you have access to cider apples or are making a sweeter cider this advice does not carry as much weight as good ciders can be made easier with out the crabs these ways.

 

[gregbathurst]

Crabs I use are mostly bittersharps, that is high tannin and high acid. Tannins help give the cider body which is why crabs are so useful. You can taste for tannins - they give your mouth that furry feeling because they react with the saliva in your mouth (astringency). Too much crab will make the cider too bitter.As wildman says, there is a lot of variation.

 

[CidahMastah]

I also heard from a somewhat local commercial cider maker (using old world cider apples), never use more than 50% of bittersweets in your blend (http://www.evescidery.com/).

So if you have some tannic crab apples that fall into the sharps (10-15%)
Bittersweets = (no more than 50%)

The big thing is just getting access to more than just dessert apples. At least here in the U.S. that is a major ordeal on its own.

I am lucky because I have some older apple trees and my neighbor has a ton of old wild apple trees on his property.

The key is getting a taste for the types you are looking for. I walk through the wild apple trees and taste as I go until I find what I want.

The great (and painful) part about cider is learning the tastes. It isn't like making a beer where you match a malt to a malt and quantity. The blend is what makes or breaks the cider. Luckily, even the bland ciders are still drinkable