DIY oat cookie press and cookie recipe
A DIY oat cookie press or cutter for making DIY oat cookies or biscuits.
Introduction
Rolled oats are a healthy source of unrefined carbohydrate with natural plant fibre that is sadly lacking in our modern refined diets. Consequently, DIY making of oat cookies from this inexpensive food makes an attractive and healthy food for active people. The flexibility of the recipe allows the incorporation of lots of DIY dried fruits, and a DIY cookie-cutter or press makes the job quick and easy.
The oat cookie press
I first made the oat cookies as a flat sheet in baking trays and sliced it up to make square biscuits. The taste was good, but the process was tedious, and sticking to the tray and the break-up of the cookies were problems. Despite my efforts, I was unable to find a suitable cookie press on the internet. So, with a selection of used RTV silicone rubber cartridges and round roll-on deodorant applicators on hand, I set out to make a suitable cookie press for the oat biscuits.
First oat cookie press. Initially, I made a rather short cutter tube, from a silicone rubber cartridge with a plunger, made from a roll-on deodorant bottle. While it worked well enough, oil expressed from the dough mix, made it slippery to hold and press out the formed cookies from the cookie cavity. With repeated usage, the dough mixture leaked past the plunger and the press had no effective stop that could automatically regulate the thickness of the cookie.
Improved oat cookie press. For the second oat cookie press, I made the cutter much longer so that I could maintain a strong grip on it and the plunger was fitted with an ergonomic slider handle for pressing the cookie out from the cavity and onto the backing tray. This time, the piston was made from a plastic deodorant applicator that was a nice fit inside the cutter tube. A slot for the slider handle could regulate the cookie thickness.
Plaster filled plunger. In order to fit a solid slider handle to the piston, I cut off the bottom of the deodorant applicator and put a small block of wood into it after forming a screw hole in it to match the thread on a roofing screw. That screw was fitted with a soft handle, made from a short length of thick-walled silicone rubber vacuum tube.
When the block of wood was held in place by the screw, I filled the cavity with plaster of Paris and allowed the plaster to thoroughly cure and then dry out above my wood stove.
Forming the silicone rubber washer on the plunger. I dressed the exposed plaster surface with sandpaper. Then I drilled multiple holes into the plaster face and used a Dremel tool to undercut these holes to provide ‘keying’ to secure a silicone rubber piston washer.
Impregnation the piston face with silicone rubber. In addition to the ‘keyed’ holes, I impregnated the holes and flat surface with RTV silicone rubber that was diluted ~1:5 with mineral turpentine. This allowed it to penetrate the plaster.
Next, I filled all the holes with ‘neat’ silicone rubber and applied a thin coating to the flat plunger surface. “I had not bonded plaster with RTV silicone rubber before. However, my extensive success with many other materials gave me confidence that it would probably work well with dry plaster that is inorganic and very permeable.
In situ moulding of the silicone rubber washer. The final step was to oil the inside of the cutter wall with vegetable oil as a release agent and then set and lock the plunger surface at about 6mm below the cutter edge. The small cavity was ‘overfilled’ with RTV silicone rubber. Then I pressed the inside/bottom face of an aerosol can (also coated with oil) onto the end of the cutter to form a concave face on the moulded rubber washer.
This moulded washer on the plunger was very successful as it kept the inside bore of the cutter clear of cookie mix and it remained well bonded to the plaster through moulding extraction process, use in making cookies and the eventual washup of the press.
Cutting and pressing oat cookies
To act as a lubricant for the piston washer and the release of the cookies from the mould, I started by dipping the press in a shallow pool of olive oil. I soon realised that this was not neccesary as the compression of the cookies was causing the mix to self-lubricate the surface of the cookies and the piston washer.
Using this DIY cookie press made the cookie formation easy. Pressing downwards on a compact layer of warm cookie mix (20-30 mm thick) formed neat and uniform cookies. Pressing the slide handle downwards easily ejected the cookie onto the baking sheet. Residual mix left over from cutting could be quickly reformed into a thick sheet to start cutting again. In this way, all of the cookie mix could be utilised.
When I ran out of baking capacity, I could still keep pressing cookies out onto the thin cutting sheet (shown in the photo above). This meant that the cookie pressing could be completed while some cookies were baking. In this way, all the firmly formed cookies could be pressed out while the mix was warm and pliable. Then they could easily be slid across onto the baking trays as they became available.
The high compressive load involved in this type of cutter/press seems to bring some of the oil in the mix to the surface. This surface oil lubricates the press and prevents sticking to the mould and also allows the cookies to easily separate from the silicone rubber mats when cooked.
When using the cookie cutter/press, the downward force required to form clean edges was considerable, particularly as the mix has wide oat flakes and dried fruit particles that otherwise form ‘daggy’ edges. This force is provided by hand pressure on the other open end of the cutter as the walls of tube become too slippery. While not forming cookies from my hands while making 66 cookies with the cutter, it was a little harsh on my hands that are accustomed to hard farm work.
Consequently, as an afterthought, the design was improved by providing a removable flat top for the press. For this device, I cut off the top of another deodorant bottle and forced the lid halfway into it (round end first) and the remaining protruding half made a connector to go inside the top end of the cookie press tube. A tight fit was made by shimming the connection zone with PVC electrical tape.
The oat cookie recipe
The recipe below can be very flexible and could easily be varied according to your food fibre desire, taste, tolerance, and availability of DIY dried fruit and spices on hand. A small amount of self-raising flour and the sodium bicarbonate rising seem to be essential for the desired baked cookie formation and slight rising and expansion during baking. The oil content appears to be helpful for the easy release of formed cookies from the mould and easy handling of the cookies before and after baking.
2 cups of rolled oats, 1 cup each of muesli, full cream milk powder, self-raising flour, wholemeal flour and 0.5 cup of dessicated coconut,
4 tsp cinnamon, 1 tsp mixed spice, 4 tsp kibbled or powdered ginger
Mix the above dry ingredients.
Add dried fruit to taste, including apples (or other home-dried fruit), dates, and sultanas (0.5 cup each).
Mix: 0.5 cup of treacle, 1 cup of raw sugar. 0.5 cup of olive oil and 1.0 cups of water. Bring this mixture to the boil and add 0.5 tsp of sodium bicarbonate. Then add the frothing mixture to the other dry ingredients and mix well.
Press the cookie dough out on a thin plastic cutting sheet as a compact layer that is about 20 to 30mm thick. Then, with the piston of the cookie-cutter protruding from the cutter, press it downwards through the dough so that the piston will rise to the stop and the cookie cavity is tightly packed with dough. Then the cookie can be expelled onto a silicone rubber baking sheet in a shallow baking tray.
Bake at ~160C for about 20 minutes until they start to brown.
If the baking trays are fully utilized, the pressed cookies can be placed on a thin plastic cutting board. Then they can be easily transferred onto the baking trays when they become available. I think the oil in the mixture lets the pressed cookie release easily from the sheet.
This recipe makes 66 cookies, ~20mm thick and 50 mm in diameter. I am sure that the ingredients can be varied greatly according to your taste and will still make a satisfactory cookie.
Post-cooking softening
My first batch of cookies was a little dry and hard (not enough water in the mix and baked too long). Consequently, I put a ‘slosh’ of muskat into the storage canister and this eventually softened the cookies. It gave the cookies a nice additional fruity flavour that is now expected by my family, regardless of the original baking defect.
To make the cookies uniformly soft, I rolled the canister in all directions over a couple of days. During this time, the wine equilibrated throughout all the cookies. In this regard, fortified wines make a wonderful moistening/softening agent that will not cause mould growth and often will prevent it.
Conclusion
This DIY cookie press works well for oat cookies and I expect it will also work well with less chunky cookie doughs, provided that they have significant oil, butter or other lubricating lipid content to help the cookie release from the mould.
Longer or shorter slots could be made, in the cookie press tube, so that thicker or thinner cookies could be pressed with the same device.
Tim
