What is an Extract?
An extract is a preparation that results from taking raw plant material and applying a solvent to it, such as water or alcohol. The solvent causes the dis-solvable compounds to be separated from the structural part of the plant or mushroom.
Extracts contain high levels of the active ingredient a particular herb or mushroom is known for, such as the beta-glucans found in most medicinal mushrooms.
Another advantage of extracts over raw herbs is higher bioavailability – a fancy term that means they are easier for the body to absorb and use. In the case of mushrooms, the extraction process breaks down chitin – the indigestible cell wall of fungi that contains the main active ingredients. For these reasons, extracts are frequently used to manufacture dietary supplements.
Extracts can come in liquid or powder form. When it comes to mushrooms, the most common way to characterize extracts is by what solvent they use: water, alcohol, or both.
What is a Hot Water Extract?
A hot water extract is exactly what it sounds like – using hot water to dissolve water-soluble ingredients from raw herbs or mushrooms. In this method, the raw material is heated in water at a temperature of about 80–175°C for a certain period of time.  After the extraction is done, the remaining solid plant material is typically discarded, and the water is evaporated to leave behind a powdered extract.
Hot water extracts are commonly used for preparing mushroom supplements because the main active ingredient in the vast majority of medicinal mushrooms – beta-glucans – are water-soluble.
What is an Alcohol Extract?
As the name suggests, an alcohol extract uses alcohol instead of water as the solvent. The most common type of alcohol used for this method is ethanol. Extraction with alcohol causes the alcohol-soluble compounds to separate from the raw herb or mushroom material.
Alcohol extracts are typically used to isolate terpenes (specifically, triterpenoids), sterols, and flavonoids, which are the main non-water-soluble active compounds present in some mushrooms.
What is a Dual Extract?
In some cases, it may be beneficial to use both water and alcohol extraction – a method referred to as a dual or double extraction. In a dual extract, the material is first extracted with either hot water or alcohol, and then the remaining plant material is extracted again with the other method.
Next, the liquid from the first extraction is combined with the liquid from the second extraction, forming what is now called a dual extract. Dual extraction is typically used for mushrooms that contain significant levels of both water-soluble and alcohol-soluble active ingredients, such as the chaga and reishi.
Most herbalists favor doing a hot water extraction first and the alcohol extraction second, but there is some disagreement on this topic. 
Which Extraction Method is Best for Specific Mushrooms?
When shopping around for mushroom supplements, it is beneficial to know what kind of extraction method is used for your specific product. This will ensure that you are getting a high-quality supplement that actually works.
If you are looking for a Cordyceps, Lion’s Mane, Turkey Tail, shiitake, or maitake mushroom product, you should look for a hot water extract product. This is because their most important active ingredients – beta-glucans – are water-soluble. Using alcohol or dual extraction for these mushrooms is not desirable, because alcohol would cause some of the the beta-glucans to solidify and be filtered out of the liquid.
On the other hand, the reishi and chaga mushrooms benefit from dual extraction because they contain both water-soluble beta-glucans and alcohol-soluble terpenoids.
However, there is one exception to this case: hot water extract products that include the raw material that remained after the extraction process. In this situation, the non-water-soluble compounds would still be present in the final product since the remaining mushroom material was not discarded. As such, both dual extracts and hot-water extracts can be used to make effective reishi and chaga mushroom products.
Dual is Not Always Best
We hope this article helped shed some light on what hot water, alcohol, and dual extracts are, and why they matter when it comes to medicinal mushroom supplements.
Although the word “dual” sounds like it should lead to better results, as we’ve discussed above, dual extracts are not always necessary and can actually be detrimental.
As such, it’s important to use this information when choosing your next mushroom product.
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1.Plaza, M., & Turner, C. (2015). Pressurized hot water extraction of bioactives. TrAC Trends in Analytical Chemistry, 71, 39-54.
2.Buhner, S.H. (2012). Herbal antibiotics. North Adams, MA: Storey Publishing.