Purana ghrita is ghee that has been deliberately kept for years. Charaka's text, as summarised in a 2023 Ayurveda paper, calls ten-year-old ghee purana and 100-year-old ghee prapurana. Chemically, ageing raises the free fatty acids and peroxides that measure rancidity. Whether a given jar still counts as ghee under Indian food law depends on laboratory figures, not on its age.
This article covers the tradition and the chemistry. It is not advice to use aged ghee as a medicine: if you are thinking of doing that, follow your doctor's advice first.
At a glance
- A 2023 paper by Chavan and colleagues says the Charaka Samhita describes ten-year-old ghee (purana) and 100-year-old ghee (prapurana) as pungent-bitter, strong smelling and like lac juice in appearance.
- In a 2020 storage study by Gurav and colleagues, plain cow ghee's acid value rose from 0.335 to 0.649 over 12 months at room temperature, and its peroxide value from 1.581 to 3.590.
- A ten-year-old purana ghrita analysed by Yadav and colleagues in 2013 had an acid value of 1.57, about 0.79 per cent free fatty acids on FSSAI's conversion.
- FSSAI's standard for ghee allows at most 2.0 per cent free fatty acids as oleic acid and sets no peroxide value limit for ghee.
- FSSAI's labelling regulations require an expiry or use-by date on packed ghee and say food past its use-by date shall not be sold.
What is purana ghrita?
Purana ghrita means old ghee: plain ghee stored for years on purpose, not ghee cooked with herbs. The Charaka Samhita, as summarised by Chavan and colleagues in 2023, describes ten-year-old ghee as purana and 100-year-old ghee as prapurana, with a pungent-bitter taste, a strong irritant odour and an appearance like lac juice.
The same paper says Charaka describes this ghee as useful in insanity (unmada), epilepsy (apasmara) and grahadosha. That is a description of the classical text, not evidence that it works. A 2024 review of eleven Ayurvedic texts by Kataria and Singh, of the University of Delhi and the University of Trans-Disciplinary Health Sciences and Technology, found that old ghee (purana ghrita) is "highly regarded" in Ayurveda. How ghee fits into the wider system is in ghee in Ayurveda.
How is aged ghee different from medicated ghee?
Aged ghee is plain ghee left to age; medicated ghee is ghee cooked with herbs and a liquid to a recipe. The two meet in some medicines: Brahmi ghrita, for example, is made with purana ghrita as its base. Tradition also treats their age differently: old plain ghee is prized, while medicated ghee is said to lose potency.
In the 2013 analysis of Brahmi ghrita by Yadav and colleagues, herb paste and liquid "were mixed in Purana Ghrita and heated for three hours at 110°C every day for three days". The 2023 paper by Chavan and colleagues reports that the classical author Bhavamishra held that medicated ghee loses its potency after one year, and that the Ministry of AYUSH has published a shelf life of two years for medicated ghee. Old plain ghee, by contrast, is "highly regarded" in the texts reviewed by Kataria and Singh. The making and regulation of herbal ghees is covered in medicated ghee (ghrita): what it means.
What happens to ghee chemically as it ages?
Two slow reactions. Fat molecules break apart and release free fatty acids, which the acid value measures, and the fat reacts with oxygen to form peroxides, which the peroxide value measures. Both rise with time and faster with heat. The FSSAI method manual calls acid value "a relative measure of rancidity".
The clearest measurements come from a 2020 laboratory study by Gurav and colleagues in the Journal of Ayurveda and Integrative Medicine. They stored plain Indian cow ghee in closed glass bottles at room temperature and at 40 °C with 75 per cent humidity, and tested it every three months for a year.
- Acid value at room temperature went from 0.335 to 0.649 in 12 months, nearly double (0.649 ÷ 0.335 = 1.94).
- Peroxide value at room temperature went from 1.581 to 3.590, more than double (3.590 ÷ 1.581 = 2.27).
- At 40 °C the peroxide value reached 5.982 at 12 months, almost four times the starting figure (5.982 ÷ 1.581 = 3.78).
- Colour faded from golden yellow to pale yellow after 12 months at the higher temperature.
- Taste and smell changed from aromatic and pleasant to "slightly fragrant and bitter taste" after 12 months at the higher temperature.
Heat matters in other studies too. A study from the ICAR-National Dairy Research Institute found that over 21 days peroxide value, TBA and free fatty acids of ghee rose significantly at 60 °C compared with cooler storage. Peroxides also track flavour: in a 2015 study at Anand Agricultural University, peroxide values of ghee stored at 80 °C were negatively correlated with flavour scores: higher peroxide went with lower flavour scores. Everyday storage advice is in ghee storage and shelf life.
What did a ten-year-old ghee look like in the laboratory?
We found one aged sample reported in detail. The Yadav team obtained ten-year-old purana ghrita from a shop in a Varanasi market and found it golden yellow with "a peculiar smell". It had an acid value of 1.57, a saponification value of 199.15 and an iodine value of 31.04. Its peroxide value was not reported.
Set against the FSSAI standard for ghee, those figures give a mixed picture. FSSAI's oils and fats manual says acid value equals per cent free fatty acids (as oleic acid) multiplied by 1.99, so an acid value of 1.57 is about 0.79 per cent (1.57 ÷ 1.99), inside the 2.0 per cent limit. The iodine value of 31.04 sits within the standard's 25 to 38. The saponification value of 199.15 is below the standard's range of 205 to 235.
That is one jar, tested by one laboratory, so it cannot speak for every aged ghee. It does show that a decade-old ghee is not automatically outside the free fatty acid limit, and that it can still fall outside the standard on another line. A batch report shows these lines for any ghee, aged or fresh; how to read a ghee lab report explains them.
Fresh and aged ghee, side by side
The figures come from different laboratories and ghees, so treat them as rough markers. Free fatty acid percentages are calculated from acid value using FSSAI's factor of 1.99.
| Ghee | Colour | Smell or taste | Acid value (free fatty acids) | Peroxide value | Source |
|---|---|---|---|---|---|
| Plain cow ghee at the start of storage | Golden yellow | Aromatic, pleasant | 0.335 (about 0.17 per cent) | 1.581 | Gurav 2020 |
| Same ghee, 12 months at room temperature | Not reported separately | Not reported separately | 0.649 (about 0.33 per cent) | 3.590 | Gurav 2020 |
| Same ghee, 12 months at 40 °C | Pale yellow | Slightly fragrant, bitter | 0.722 (about 0.36 per cent) | 5.982 | Gurav 2020 |
| Purana ghrita, ten years old | Golden yellow | "Peculiar smell" | 1.57 (about 0.79 per cent) | Not reported | Yadav 2013 |
| Classical description of ten-year-old ghee | Like lac juice | Strong irritant odour; pungent-bitter | Not measured | Not measured | Charaka, per Chavan 2023 |
| FSSAI limit for ghee | Not specified | Not specified | At most 2.0 per cent free fatty acids (acid value about 3.98) | No limit set for ghee | FSSAI 2.1.8 |
The FSSAI acid value equivalent is 2.0 × 1.99 = 3.98. The standard does set peroxide limits for butter oil (0.6) and anhydrous milk fat (0.3), but leaves the ghee column blank.
Can aged ghee still be sold as ghee in India?
Only if it still meets the standard and its label date. FSSAI's standard for milk fat products names the product ghee by its composition and says nothing about age. A packed ghee must carry an expiry or use-by date, and food past that date "shall not be sold or distributed for human consumption".
The labelling regulations list the foods that do not need an expiry date, such as wine, vinegar and solid sugars; ghee is not among them. The Food Safety and Standards Act, 2006 calls food sub-standard if it "does not meet the specified standards", and section 51 sets a penalty of up to five lakh rupees for selling it.
So a seller offering ghee aged ten years as food needs a use-by date that covers it and figures that pass the standard. Whether aged ghee sold for medicinal use falls under the drug rules instead is a separate legal question that this article does not settle.
Is there evidence that aged ghee works as a medicine?
We found none. The claims for purana ghrita come from classical texts, and a PubMed search for "purana ghrita" on 13 October 2026 returned two papers, neither a clinical trial. A 2018 review of Ayurvedic medicine for dementia says old ghee "is described in Ayurveda as a memory enhancer", and also that large multicentre clinical trials of Brahmi ghrita in patients with dementia have not been performed.
The 2018 review is a description of tradition and laboratory mechanisms, not a test in patients. If you or someone you care for has epilepsy, dementia or a mental illness, follow your doctor's advice rather than a traditional remedy.
The short version
Purana ghrita is ghee kept for years on purpose; Charaka's text, as summarised in a 2023 paper, calls ten-year-old ghee purana and 100-year-old ghee prapurana. Storage studies show acid value and peroxide value rising with time, faster with heat. One ten-year-old sample stayed under FSSAI's 2.0 per cent free fatty acid limit but fell below its saponification range. Under Indian food law, aged ghee is ghee only if it passes the standard and is within its label date. Its traditional medicinal uses have not been tested in trials, so follow your doctor's advice.
Sources
Further reading behind the figures above. Himdhara's own numbers — yields, batch results — come from our production records and the batch reports on the lab reports page.
- Food Safety and Standards Authority of India. Chapter 2.1: Dairy products and analogues (2.1.8 Standard for Milk Fat Products). Food Safety and Standards (Food Products Standards and Food Additives) Regulations, 2011.
- Food Safety and Standards Authority of India (2025). Food Safety and Standards (Labelling and Display) Regulations, 2020, Version VIII. FSSAI.
- Chavan S, Bhuvad S, Kumbhalkar B, Walunj T, Gupta V, Deshmukh V, Sardeshmukh S, Sardeshmukh S (2023). Lipid-based ayurvedic formulations of a single herb-Yashtimadhu (Glycyrrhiza glabra): Pharmaceutical standardization, shelf-life estimation and comparative characterization. Journal of Ayurveda and Integrative Medicine.
- Gurav NS, Gurav SS, Sakharwade SN (2020). Studies on Ashwagandha Ghrita with reference to murcchana process and storage conditions. Journal of Ayurveda and Integrative Medicine.
- Yadav KD, Reddy KR, Agarwal A (2013). Preliminary physico-chemical profile of Brahmi Ghrita. Ayu.