Which do you like?
There are rather hard and dry. You almost see no oil separating to top. It is getting harder and harder to get as you dig deeper. It is also harder to spread and feels dry in mouth. My assessment! This could be less grease or added with filler like cornstarch or wheat flour. If there is really no sign of oil separating to top, then some kind of emulsifier is mixed during the process, skim milk perhaps.
Fluid. If you are fan of the above described product, then, fluid kind might not be your type. It is probably due to two reasons. It is either no filler is mixed or too much oil is added. This has the advantage of creamier texture but expect a faster clear oil formation.
Chunky. It contains whole roasted peanut inside. It feels like crackers within a bread. Rather, a crackling in spread if you are eating the product as is. I prefer this as I enjoy the cracking sound. Whole roasted peanuts have the tendency to float so stirring it a bit before use is advised.
Chocopeanut. A friend of mind tried making this by mixing peanuts and cocoa nibs. The lowest possible proportion of nibs with acceptable chocolate flavor hardened the end product. He did not try using cocoa powder which I think is more suitable.
For the masses. The affordable which cost more or less twenty pesos and available in many sari-sari stores. Usually sweet, rough textured, visible peanut skins and some tiny bubbles. Often unlabeled and you never know who to go after in case of food poisoning.
If you are looking for all natural and unsweetened product. There is no other place to look at except for vegetarian shop. Just keep in mind that oil separation is a natural phenomenon and you can always stir it before use. Do not consume on the slightest sign of rancidity.
The popular oil extraction methods.
The solvent extraction. The oil-rich commodity is bath with hexane, the likes of petroleum ether. It dissolves the commodity oil content. The oil is then purified by boiling the hexane off.
Hexane has low boiling temperature, about 36 to 50°C. Boiling to such temperature range will drive the hexane off and leave the oil behind. The solvent is collected in another chamber and use for repeated extraction.
This method is high yielding and preferred by big commercial processors.
Screw press. Can either be slow speed and temperature regulated or equipped with cooling mechanism to protect sensitive oils. A low yielding method meant for production of higher quality and healthier oil. Or, high speed and heated process. High speed screw press rotation tend to produce heat which aids extraction. If the heat produced is not enough, external heat source is applied.
Press and ferment. As far as my knowledge is concern, this method is only applicable to virgin coconut oil. Grated coconut is pressed to expel out mixture of oil, water and other substances. Then naturally fermented overnight to let oil separate on top.
..press and boil. Instead of boiling, the extracted liquid is boiled to allow evaporation of unnecessary portion. The method yield more but lower quality oil.
The cocoa butter extraction process. Extracted by batch press. Roasted nibs are subjected to milling producing fine textured liquor. Then butter is extracted via batch press while still in liquid state.
Can cocoa butter be extracted by solvent extraction? I think it can be! Repeatedly bath the roasted nibs in hexane. Then heat the solution to hexane boiling temperature to get purified cocoa butter.
It is possible but likely to have detrimental effects on flavor and safety. Roasting process develops cocoa flavor. Why take a risk by adding harmful and odor offensive hexane? It can be removed by heating but we never know the effect it may cause or whether it is completely removed or not.
Wanna take the risk?
A peanut butter with no added oil, sugar, emulsifier and other preservatives.
Oil is added to give it a more fluid texture during milling process. A more fluid mixture is easier to grind in a burr mill or chop in a heavy duty blender. Some customers prefer more fluid or spreadable texture. And, it adds volume. Cheap sari-sari store brands often have very flowy appearance and might have generous amount.
Sugar. Added to fulfill the taste requirement of general public – the sweet preference for taste. All the peanut butter I have tasted so far are sweetened. I never know much about statistics but some might be looking for a plain peanut butter taste without the hugging sugar sweetness.
A syrup adds volume and gives a less viscous texture.
Emulsifier. Most peanut butters have this kind of texture, a soft oily and flowy top but a dry and hard bottom. Sometimes a layer of oil is visible on top, seems like an ordinary cooking oil. A peanut butter with uniform texture from top to bottom contains emulsifier to prevent oil separation.
Other preservatives like antioxidants. Peanut contains considerable amount of oil and it is prone to rancidity. Antioxidant is added to prevent such. Naturals, like Vitamin E is acceptable, rejected otherwise.
Here it goes…
1) Get good quality peanuts. Buy peanuts with or without testa. Choose the latter to save the trouble of removing the thin skin.
2) Pan roast peanuts as stated here. Never add any oil. Set the temperature to low and stir continuously to prevent scorching.
As I said before, roasting time is affected by quantity of peanuts. I roasted one kilogram peanuts for one our. I liked it garlic flavored so I also added three cloves crushed garlic. Another way to test end of roasting is by eating a roasted sample. It should be crunchy and no traces of raw taste.
3) Grind the roasted peanut using a steel burr mill. Pass it several times to achieve the desired consistency. Using a high speed electric mill is recommended. Using home to heavy duty blender is discouraged. A fine texture is not possible in absence of additional oil or syrup.