The one citrus eaten whole, skin and all; sweet skin, sour flesh.
The peel adds fibre and aromatic oils.
The most nutritious part of citrus is the part people discard. A kumquat is small enough that the peel becomes the point, so you get compounds from the skin that a peeled orange never delivers.
Whole-fruit fibre with the peel, no preparation, and easy portioning. A small bowl of kumquats is a low-effort way to keep winter fruit in the day.
Vitamin C in a very small package; aromatic oils that most citrus eating misses.
Chapter 2 of 12
Traditional Uses in Persia and East Asia
Persian temperament: Warm & Dry (1st degree). The peel carries the warmth, the juice the cool. Eaten whole the fruit reads as mildly warming, which is why winter is its season.
In Persian and East Asian practice the small sour citrus fruits are read as warming and drying in the peel, cooling in the juice. Kumquat preserved in honey or salt was kept for winter and taken for a scratchy throat and a stubborn cough. This is traditional use.
Peel used for its aroma to settle the stomach after a heavy meal.
Potted kumquat trees are a Lunar New Year symbol of prosperity in southern China, kept indoors covered in fruit. In Iran the fruit is a newer arrival, sold in the northern citrus markets alongside mandarins.
Chapter 3 of 12
What It Contains
Primary compounds
Essential oils (limonene); flavonoids (a family of protective plant compounds). Pectin (a soft fibre in fruit that thickens jam).
Vitamins
Vitamin A, Folate
Other notable constituents
Minerals: Calcium, Potassium, Manganese · Antioxidants: Carotenoids (the orange and yellow plant pigments your body can use)
Chapter 4 of 12
What Studies in People Show
What studies in people show
Higher dietary fibre intake is associated with lower all-cause mortality across large cohorts.Strong evidence
Vitamin C intake from whole fruit is associated with better markers of immune function than supplement intake alone.Moderate evidence
Chapter 5 of 12
Preparation and Kitchen Use
Roll the fruit to warm the peel oils before eating.
In the kitchen: halve and remove the few seeds if they bother you. Honey preserve: whole kumquats simmered in honey and stored cold. Whole and fresh, rolled first between the fingers.
Chapter 6 of 12
Preparation and Kitchen Use: Other Ways to Use It
In the kitchen: sliced thin into salads for a bitter-sweet edge and roll it between your fingers first — it releases the oils.
Eat whole, two or three at a time.
Slice into rounds over a salad or a plate of rice.
Chapter 7 of 12
What It Goes With
Honey:
Honey
Simmer them whole in honey for twenty minutes and you have a winter preserve that keeps for months.
Pairing:
Walnut
Sharp peel against oily nut. Three kumquats and a handful of walnuts is a real afternoon snack.
Grain:
Rice
Sliced thin over a plate of rice, the way a Gilani cook uses barberries.
Tea:
Black Tea
Drop a halved kumquat into the glass instead of sugar and see whether you miss the sugar.
Chapter 8 of 12
Who Should Be Careful
General caution:
Wash well — the peel is eaten, so any wax or spray goes with it.
General caution:
Sour enough to bother a sensitive stomach in quantity.
Children:
Honey preserves aren't for infants under one year.
Allergy:
Rare citrus allergy.
Chapter 9 of 12
Medicines and Interactions
Medication interaction:
Statins (cholesterol-lowering medicines) metabolised by CYP3A4 (simvastatin, atorvastatin) — Kumquat isn't grapefruit and has not been shown to block this enzyme, but it's a citrus and the data are thin. Keep intake ordinary if you take one of these. (low concern)
Medication interaction:
Warfarin — The vitamin K in the peel is small but real. Steady intake matters more than the amount. (low concern)
Chapter 10 of 12
Pregnancy, Children and Older Adults
Pregnancy and breastfeeding
Pregnancy and breastfeeding:
Fine as food, and the folate is useful. Wash the fruit properly, because the peel is eaten and nothing gets peeled away. Skip the honey preserve if you want to avoid raw honey, though simmering settles that.
Children
Children:
Children either love the sweet-sour surprise or refuse it outright. Halve them for anyone under four and take the seeds out. Honey preserve isn't for babies under one year.
Older adults
Older adults:
Easy to eat, needs no peeling, and portions itself. For anyone who has stopped bothering with fruit because of the preparation, a bowl of kumquats removes the excuse.
Chapter 11 of 12
Through the Year
Spring:
Spring
The last of the crop turns soft. Cook these into preserve.
Summer:
Summer
Out of season, and the travelled fruit tastes of nothing.
Autumn:
Autumn
First fruit arrives late and sharp. Preserve-making time.
Winter:
Winter
The fruit's moment: a bowl on the table, two or three at a time.
Chapter 12 of 12
Questions People Ask
Do you really eat the skin?
Yes. The peel is the sweet part; the flesh is the sour part.
Why roll it first?
Rolling breaks the oil glands in the peel and releases the aroma.
How many is a sensible amount?
Four or five in a day is a fruit portion. They are small, so it's easy to eat a dozen without noticing, and at that point the acid starts to tell on a sensitive stomach.