Extremely soft cheeses, such as cream cheese and paneer, do not require rennet. Their coagulation is made possible via acids, such as vinegar, citric acid, or the lactic acid that naturally comes from milk. But for everything else you need rennet.
Types of rennet
There are basically two types of rennet. The oldest and most common way to source rennet is from the stomach lining of young, unweaned calves. These animals are not killed expressly for their rennet; rather they are killed for meat production (in this case, veal) and the rennet is a byproduct.
You can learn more about making rennet in a traditional manner by watching this video excerpt from the BBC show Victorian Farm.
The second most common method is plant-based and while it doesn’t work well for very hard cheeses that need long aging periods, it does work for other cheeses. Knowing how to make vegetable rennet is very handy when you don’t have a calf you wish to butcher.
Stinging nettle is painful to touch; wear gloves and long sleeves to protect yourself from this plant’s irritating leaves when harvesting. Check books on wild foraging or edible weeds for proper plant identification.
Harvest nettle leaves before the plant has gone to seed. Once the nettle has seeded, it is unsafe to use for making rennet. Harvest nettle leaves into a clean paper sack.
And while you are out there harvesting nettles for rennet making gather some extra too as Nettle Tea is supposed to be good for easing arthritis pain, controlling blood sugar levels, reducing seasonal allergy symptoms and may lower blood pressure. More studies need to be done on these claims but early results show promise.
If fresh nettle is not available in your area, check local natural food stores. Dried nettle leaves are readily available, as they are often used for tea. Substitute ¾-1 pound dried nettle for 2 pounds fresh leaves.
How to make nettle rennet
- 2 pounds fresh stinging nettle (urtica dioica)
- Large pot
- 1 Tbsp. Sea Salt
Instructions for making nettle rennet
- Rinse 2 pounds fresh leaves under cool, filtered water.
- Fill a large pot with 4 cups water. Add the clean leaves. Add more water if needed to just cover the nettle leaves. Bring the water and leaves to a light boil; reduce heat, cover and simmer 30 minutes.
- Add 1 heaping tablespoon of sea salt to the pot; stir gently to dissolve. The salt will help to break down the leaves and release the coagulating enzyme.
- Place a colander inside a large bowl. Line the colander with one layer of clean cheesecloth. Pour nettles into a colander. Drain until leaves stop dripping.
- The liquid drained from the nettle leaves is the liquid nettle rennet. It can be used in amounts of 1 cup of nettle rennet per 1 gallon of warmed milk.
- Keep tightly covered and avoid exposure to light. Nettle rennet will keep in the refrigerator or cold storage for a few weeks if stored properly.
How to use nettle rennet in cheese making
When using nettle rennet in cheesemaking, use slightly less salt than the cheese recipe calls for, because the rennet will be a bit salty.
Nettle rennet can be used with any milk to make cheese. However, cheese made with vegetable rennet may develop a bitter flavor if aged for a long period of time (over 2 months). Solve this problem by using animal rennet for aged cheeses, making cheeses with shorter aging periods when using nettle rennet, or merely eating the cheese younger.
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