Botanical Name – Astragalus membranaceus
Chinese Name – HUANG QI
English Name – Milk Vetch
Fluid Extract made by a process of hydro-ethanolic percolation, with a ratio of 1 part Milk Vetch Root to 1 part liquid. Liquid comprises of 70% water and 30% sugar beet derived ethanol.
Astragalus membranaceus, commonly called Milk Vetch, is a flowering plant in the family Fabaceae. Found mostly in East Asia – China, Mongolia and Siberia. It is one of the 50 fundamental herbs used in traditional Chinese medicine.
Astragalus membranaceus is a perennial plant which can grow up to 0.3 m, preferring light, sandy and loamy well drained soils. It cannot grow in the shade. Generally flowering from June to August, the seeds ripen from July to September. Bees and butterflies are the main pollinators.
Product is supplied in amber PET bottles with tamper evident screw tops. This keeps the contents fresh and protected from light. Look out for the QR code on the label - you can scan this with your smartphone to download the Certificate of Analysis document for this product.
What is a Fluid Extract?
A herbal fluid extract is a concentrated extract of one or more herbs. The liquid in a fluid extract is a combination of alcohol and water. A fluid extract must contain at least 20% alcohol for preservation purposes. Alcohol concentrations tend to vary between 20% and 60%, but can be as high as 90% in some circumstances. At Herbal Apothecary we generally produce fluid extracts with alcohol concentrations of 25% - 45%. We use ethanol derived from sugar beat.
How Is A Fluid Extract Made?
To produce Astragalus membranaceus / HUANG QI / Milk Vetch Root Fluid Extract we combine a quantity of herb with an equal liquid. The herb, alcohol and water is placed in a production vessel suitable for the size of the batch.
Traditionally, fluid extracts have been made by a process of maceration. This is where the herb sits in the liquid and over a period of time the plant cells break down. This allows the plant matter to be released into the liquid. Occasionally the producer might agitate the mixture to help the process along.
At Herbal Apothecary we have spent decades improving our fluid extract production processes. We use a system called Hydro-Ethanolic Percolation. Percolation is where liquid slowly passes through the herb, from top to bottom. In our case, the liquid is not simply passed through the herb once and then collected. Instead, it is continually cycled through the herb. Hydro-Ethanolic Percolation is a combination of maceration and traditional percolation. The circulation of liquid through a spray head agitates the herb, helping the key chemical compounds to be released into the liquid.
Our production vessels are primarily stainless steel. We use low voltage (24v) pumps to circulate the liquid. We have also developed a system of float switches and relays. These ensure the pumps only activate when an adequate level of liquid is present in the sump at the bottom of the vessel. It can take some time for the liquid to filter through the herb.
We produce most of our fluid extracts using dried herbs, although we sometimes use fresh. It's important that the size of the pieces of herb in the production vessel are small enough for the alcohol to thoroughly penetrate. No prior processing is required for flowers and leaves which are smaller and more delicate. However, for roots, bark and berries which tend to be tougher and larger we use herbs which are diced up into small pieces. This ensures that the maximum amount of plant material can be extracted into the liquid.
The manufacturing process takes 7 days to complete. Once the process is finished, the herb is pressed to extract every last drop of precious liquid. The Astragalus membranaceus / HUANG QI / Milk Vetch Root Fluid Extract is filtered and then stored in bulk containers, before being bottled in smaller 250ml, 500ml and 1000ml quantities.
Click here if you'd like to know more about our herbal tincture manufacturing technology. At Herbal Apothecary we are committed to research - we want to provide a robust evidence base for the products we produce. As a result we review our manufacturing systems and processes in order to ensure we're making best use of the raw ingredients.