A bladder press, also called a water press or Idro press, uses water pressure from a garden hose to fill and
expand a rubber bladder inside the press. The expansion of the bladder presses the fruit. The bladder
expands uniformly and applies pressure against a larger surface area than a ratchet press, which results in
more juice extracted. It is much gentler to the grapes than a ratchet press, not imparting bitter tannins
from cracked seeds and over-pressed skins.
A bladder press is very efficient compared to a ratchet press. With one load in a 40L bladder press, the
whole process from setup to breakdown will take about an hour. One load- press & clean cycle takes around 20 minutes. The actual pressing time with a 40L press is about 10 minutes.
Bosagrape Winery & Brew Supplies sells a range of sizes of bladder presses.
Important Notes
Please read the manual included with your press for complete safety information.
You must use water to inflate the bladder. Do not use air – you will burst the bladder.
Tips:
Pressing is messy – don’t wear nice clothes! Reduce spattering by covering the press with a
heavy duty plastic press bag or similar cover.
You may want to use a heavy-duty mesh bag inside the press basket to keep fruit pulp from squeezing through the holes in the basket.
Store your press out of the sun. Exposure to sun may cause the bladder to become brittle.
Setting up the press:
- Set up the press on a flat and stable surface, in an area that
can be easily cleaned with water. - Make sure the press is clean before using. You don’t need to
sanitize it, as you will be adding sulfite to the fruit after
pressing. - If you are using a mesh pressing bag, put it inside the SS
basket, as close to the inner wall as possible to allow the
most room for the fruit. Fold the top edge of the bag
outward over the top edge of the basket to hold it in place. - Grapes should be de-stemmed and crushed. Hard fruit like
apples need to be shredded before pressing. - Reassemble the press. Leave the lid off.
- Place a container under the press spout to collect the juice.
- Loading the press:
- The basket needs to be full for each pressing cycle, or you risk bursting the bladder. Rice hulls can be added to the press if you don’t have enough fruit to completely fill the press.
- Fill the basket completely. Wait for the must to settle. Top up once or twice after must settles.
- If you are using a plastic pressing bag to reduce spattering, place it upside down over the press.
Pressing: - Replace the lid and screw down the black handle.
- Attach the end of the hose with the quick connector to the press. Attach the other end to your
water outlet. - Open the air relief valve at the top of the press. Slowly turn on your tap. The bladder will start to
fill with water. When water comes out of the air relief valve, you know that all the air has been
pushed out of the bladder. Screw the air relief valve closed to begin expanding the bladder and
pressing your fruit. - Slowly let the bladder fill until the juice stops flowing. The pressure relief valve will open
automatically if you exceed 3 bar pressure. Adjust your hose pressure at the tap. - When no more juice is coming out (or when you no longer like the taste of the juice coming out),
turn the water off.
The best way to decide when to stop pressing is by taste rather than by pressure. With red wines, you can generally taste that the wine is becoming more astringent as more tannins are pulled from the skins. As a general guideline, most commercial wineries press to 1.5 to 2 bar (14 to 28 psi).
After pressing:
The skins and pulp will be pressed into a thin wall around the inside
of the press, and will feel slightly moist but not wet. - Open the emptying tap to drain the water from the bladder.
You may want to collect the water for cleaning or for
watering plants. - Once the bladder is empty, remove the lid from the press.
Remove the basket and clean out the skins and pulp. If you
are pressing more fruit, don’t open the air valve. With the
bladder contracted, there is more room for grapes.
Cleaning the press: - Take the press apart and remove all debris. Spray everything with a garden hose until clean.
- After the last press of the season, rub a small amount of vegetable oil on the rubber bladder to
help it keep its elasticity. Your bladder will last longer