- Sugar – 1 part for every part of juice
- Pectin – 0.5% of the total weight of the mixture
- Select ripe fruits with clean, unblemished skin.
- Wash in clean water and leave to drain.
- Halve the fruits and squeeze out the juice using a manual or electric juicer.
- Preserve the peel in clean containers. Remove the white part from the inside of the peel.
- Filter the juice twice, once through a thin and once though a thick cloth.
- Weigh the juice to calculate the amount of sugar. Heat the juice slowly until boiling, in a covered pot. Add several large pieces of prepared peel. Soak the peel in the juice for 15 minutes. Remove the peel.
- Weigh the sugar so that it equals the weight of the juice. Remove 1% of the weighed sugar and keep this to mix with the pectin.
- Add the sugar to the boiling juice, dissolving it rapidly so that it does not leave crystals round the edge of the pot.
- Weigh the pectin so that it equals 0.5% of the total weight of the juice-sugar mixture. Blend with the 1% of sugar that was kept aside.
- Cut the peel in thin strips (3-4mm wide, 3cm long). Add the peel strips to the boiling mixture and cook for 5 minutes with the pot covered.
- Add the pectin to the juice and dissolve properly. Boil over a high heat until the Brix measures 64-65° with a refractometer or the temperature reaches 104°C.
- Pour the mixture into clean, sterile jars, filling it to the brim.
- Close the jars with clean sterile lids and turn them upside down to cool. Clean the jars, cool to room temperature and label.
Problems and Possible Solutions
During production of jams, various factors have to be taken into account:
1. Size of the container. The quantity of pectin indicated in the recipes is valid for containers of 1kg or less. For larger volumes the pectin content must be increased as follows:
Capacity = Increase pectin by
- 1-2.5kg = 5%
- 2.5-5.0kg = 10%
- 5.0-10.0kg = 20%
- 10.0-20.0kg = 30%
2. Finishing point. The quantity of pectin given is for a final Brix (total soluble solids) of 68%. For different final TSS, the pectin content should be increased as follows:
Final Brix = Increase pectin by
- 66 = 5%
- 65 = 10%
- 64 = 15%
- 62 = 20%
- 60 = 30%
3. Acidic taste. If the product is too acidic, replace the citric acid by tartaric acid.(63% of the amount of citric acid.)
4. Formation of clots. If the batch clots, it is probably due to the pH being too low or the TSS being too high: correct accordingly.
5. Formation of liquid at the surface. If liquid forms on the surface, it is proably due to too low pH or too low pectin content.
6. Crystallization. If liquid forms on the surface, the pH is too low – reduce the acid content. If liquid does not form on the surface, the TSS or pH is too high.
7. Formation of mould. The TSS is probably below 68° Brix. The filling may have been carried out at a low temperature. If the containers are large, wait until they are cold before closing.
8. Wrong batch. Dilute the jam with water to 30% TSS, cook briefly. Add this diluted jam to a new batch, but only at a maximum of 10% of the total mass.
For more information, contact:
BLTD Technology Resource Center
2nd Flr. Jacinta 2 Bldg., EDSA, Guadalupe Nuevo, Makati City
Email: [email protected]
Telephone: (02) 822-5087;
Truckline: (632) 822-54-18 loc. 207, 204 & 201