Kwath Kalpana/Kashaya Kalpana-
Kwath Kalpana is one of Panchvidh kalpana in Ayurveda.Now a days ,it is widely used for the treatment purpose.Kashaya or kwath means water decoction or water extract of herbs.

Kashayam,kwatham,kwath ,shruta,Niryuha etc are synonyms of kashaya.
In common language ,we are called it Kadha.

Benefit of kashaya kalpana is it is easy to digest and absorb,readily available for therapeutic action and very effect in nature as the drugs used in the preparations of kashaya are water soluble.

Methods of Preparation of kashaya-

Vidhi no 1-
Course powder (bharad) of dry herbs are taken in proportion according to Ayurvedic text,8 times of water to the herbs is added,this herbs allow to soaked in water completely overnight.Boil this prepare mixture on mild flame in wide mouth container.Reduced this mixture till 1/4th of the quantity.Then filter this prepared decoction with the help of cloth or sieve.
E.g.If we take 100 gms of course powder,then add 800ml of water and reduced it to 200ml.

Vidhi No 2-
Take 1 part of corse powder of dry herbs,add 16 parts of water,soaked it for some period of time.Boil it on mild flame,reduce it to 1/8th of the quantity.And then filter it .

This method is explained in Sharangdhara Samhita madhyam khanda,adhyaya-2
E.g.-10gms of coarse powder+160ml of water-soaked it-boil-reduced it 20 ml

Vidhi no-3-

Preparation of Decoction on the basis of Dravya quality-
If the herbs are soft-
then take 1 part of herbs add 4 times of water ,boil and reduce to 1/4th part
If the herbs are hard then-
1 part of herbs+8parts of water—>boil—>reduce to 1/4th part
If herbs are very hard then-
1 part of herb +16 part of water boilreduce to 1/4th

Prakshepa Dravya-
If sugar is to be added-
In vata Dosha-1/4th part of kashaya
In pitta Dosha-1/8th part of kashaya
In kapha Dosha-1/16th part of kashaya
If honey is to be added-
In vata Dosha-1/16th part of kashaya
In pitta dosha-1/8th part of kashaya
In kapha Dosha-1/4th part of kashaya

If powders are added-
Cumin,guggulu,kshara,salt,shilajit,hingu,trikatu-ginger,black pepper,long pepper-3gms

If liquids re added-
Milk,ghee,jiggery,oil,cow’s urine etc-12gms

Types Of Kashaya-
Based on its mode of action,kashayam divided in to following criterias-
(ref-Harita Samhita)
Tarpana-Till boiling(no reduction)
Pachana-Kashaya reduced to half
Kledana-1/4th reduction
Shamana-1/8th
Deepana-1/10th
Shodhana-1/12th
Vishoshi-1/16th

Dose- 4 tola (up to 48 ml max in one time )
Generally 20-80ml in divided dose with water
Saviryata Avadhi-24 hrs

Upkalpanas of Kashaya-
Pramathya
Laksharasa
Mamsarasa
Veshwaar
Ksheeraka
Ushnodaka
Manda,yavagu,peya,vilepi,yush,bhakti,krusara

Uses of kashaya-
Used as internal medication
Use as a anupaan
Used as bhavana dravya
Used for marana nd shodhana of dravyas
Used for vranadhavan kriya (washing of wounds)by triphala kashayam
Use for netradhavan (eye washing) in eye disoders
Use for Niruha basti karma
Use for gandush (gargling) in throat disoders
For Preparation of multiple kalpana like-sneha,avaleha,arista etc

Some Examples-
Punarnavashtaka Kwath-used in shotha,shula,swasa roga
Maharasnadi kwath-indicated in vata vyadhi
Dasmula kashayam-to regain the body sthrength ,in vatavyadhi