Simple Compost extracts can be made in less than 20 minutes, making them very convenient if there is not enough time to brew aerated tea or to leave the compost for a long soak. While the extract will contain a lower population of microbes than compost tea made from the same compost it has a longer shelf life. Aerated Compost tea only has a shelf life of only 3-4 hours, while it is claimed that an extract has a shelf life of 1- 2 weeks. I recommend checking the smell of the extract before use to check that it has not turned anaerobic. If anaerobic it will have an unpleasant smell and should not be used
The extract will also contain the range of soluble nutrients found in the original compost. Extract nade wifrom compost produced from feedstock with a good C:N ratio, when applied diluted 1:3, it has been shown to reduce growth of some weeds. so I would suggest using this dilution. https://rodaleinstitute.org/science/articles/control-weeds-with-compo
Compost extracts require a larger volume of compost than teas. It is recommended to use about a kilogram (or 3 cups) in 5 gallons of clean rainwater. It can be used as a soil drench, to boost the soil round established trees on lawns and even as a root dip during transplanting. Both the liquid and compost remaining in the bag makes a useful activator added to compost heaps.
The Extract can be made agitating or vigorously mixing compost in the water, or by running water at pressure through compost. I use sieved compost. The easiest method of doing this is to put the compost in a mesh screen bag, as would be used for making aerated compost tea. Put the bag in a container of clean rainwater and leave until the compost is soaked. I use a a 25l open container in which I have marked a 5gallon "fill-line" this gives plenty of room for mixing and makes it very easy to ladel out to finished extract using a childs watering can. Some recommended gently squeezing the bag so that the maximum number of microbes and nutrients are released. The bag can be agitated for a few minutes so that the water washes through the compost. The bag is then left for another five minutes, and the agitation repeated.
If made in the “bag” it will probably not require filtering before use.