This is another shape bag, which will adapt to different size pots, which may be an advantage.
2.5m of 100% cotton fabric
foam chips (approximately 250gms for bag + 200gms for cushion)/sheet foam/polystyrene balls [see method]
The pattern is a circle – cut two from fabric placed wrong sides together.
Easiest way to cut circle is to fold fabric along one edge to diameter of circle. Take bottom left corner at fold and place it on top edge towards the right (it won’t be at right edge unless fabric is 95-100cm wide). Then take bottom right corner created by previous fold, and fold to top left. Take top left across to top right, so you have a small triangle.
From the centre point mark a series of points 50cms away (or a little less if your bag will be 95cms wide) and join points to form a curve. Cut through all layers along this line and when you open it up you have a circle. Before you open it, mark the centre point with a pin. You can also mark part of the centre circle before unfolding, or measure out from centre once flat.
Mark the stitching lines using tailor’s chalk or pins. Try to align vertical and horizontal lines with warp and weft of fabric.
Use the fabric trimmings to cut 5cm (2″) wide bias strips for edging. Or cut two right-angled triangles and follow this neat method.
Begin by sewing 3/4 way round centre circle. Use the gap to introduce foam – I used a circle cut from a 4cm sheet of foam and trimmed the edges to slope upwards [scraps are used to stuff later], but you could stuff with chips and level. It needs to provide good insulation but be a sound base for the cooking pot.
Complete sewing round circle. Sew from centre ring towards outer edges along marked lines, stopping 5cms short of edge.
Now stuff the pockets you just made. Insert a good handful of chipped foam and push down to bottom of pocket – it is important to get it down to bottom. You can also use polystyrene balls for stuffing (but less environmentally sound than recycling foam chips). After stuffing, close top of pocket with pins or clothes pegs to hold stuffing in place while you sew – I found I could manage three pockets at a time without making too much mess. Sew around top of pockets parallel to edge.
After I had finished, I found the foam had a tendency to rise up the pocket, so I pushed it down and sewed a smaller circle about 8cms inside the outer one. You may wish to fill the pockets more or do the same – insulation at the top of pockets is not so critical as the cushion fills the top of the finished bag.
On the under side of the bag, choose a point on outer edge where fabric threads are at right angles to edge and snip towards stitching. Take a narrow piece of bias tape or fabric strip and pin, right sides together along both edges of snip.
Sew close to edges, then turn bias strip to back, turn under edge and sew flat. This creates the entrance for the cord.
Next, sew together the bias strips until you have over 3m. Sew bias strip around outer edge of fabric, right sides together and edges matching. Turn down 1cm at start and overlap by 2cm at end of circle.
Turn bias strip to the other side, fold under edge and sew close to edge and close to first stitching. This creates a strong, neat edge.
Time to thread the cord; first briefly put ends of cord in a flame, or wrap sticky tape around ends to prevent fraying. Jam end into a pen top and use pen to thread cord through outer pocket.
Push ends through stopper while pressing on centre button and tie ends to prevent them slipping back through.
Make cushion from strip of fabric approximately 90 x 48 cms (36 x 19″); fold in half, right sides together and stitch around two and a half sides. Turn to right side, stuff half full and stitch remaining side tucking edges in. Continue sewing around all sides, close to edge to strengthen. You could make cushion circular, but this makes sewing more difficult and does not really have any advantage.
You are ready to use your Cook-in bag: place hot pot in middle and pull up cord. Tuck in cushion over top of lid and tighten cord fully. Leave your food to cook!