Beginner’s Guide to Choosing Rennet — Tablets vs Liquid, Vegetarian vs Animal

If you’re new to cheese making, choosing the right rennet can feel a bit like stepping into a chemistry class. There are tablets, liquids, vegetarian versions, animal versions, microbial enzymes, strengths, dosages… and before you know it, you’re wondering whether making mozzarella at home was such a good idea after all. The truth is, once you understand the basics, rennet becomes one of the simplest ingredients in your cheese‑making toolkit. This guide will walk you through everything you need to know so you can choose confidently and start creating beautiful curds from your own kitchen.

Rennet is the enzyme responsible for transforming warm milk into a firm curd. Without it, milk would remain liquid and you’d never get the structure needed for mozzarella, cheddar, halloumi, feta or any hard cheese. Although rennet comes in different forms, they all do the same job — they just suit different styles of cheese making.

One of the first decisions beginners face is whether to use liquid or tablet rennet. Liquid rennet is often considered the easiest option, especially for newcomers. It’s simple to measure, dissolves instantly, and gives very consistent results. If you’re making small batches or experimenting with mozzarella or halloumi, liquid rennet feels very straightforward. The only downside is that once opened, it has a shorter shelf life and needs to be stored properly in a cool, dark place.

Tablet rennet, on the other hand, is the champion of long shelf life. It’s compact, stable, and ideal for people who make cheese occasionally rather than every week. Tablets are easy to store and great for larger batches, but they do require dissolving in cool, non‑chlorinated water before use. Measuring tiny portions can be slightly fiddly, and different brands sometimes vary in strength, but once dissolved properly, tablet rennet works just as well as liquid.

The next choice you’ll face is whether to use vegetarian or animal rennet. Traditional animal rennet is made from calf enzymes and has been used for centuries. Many artisan cheesemakers prefer it for certain aged cheeses because it can contribute to classic flavour development. It’s reliable and time‑tested, but it’s not suitable for vegetarians and can be harder to source in small quantities.

Vegetarian rennet, usually microbial rennet produced from Rhizomucor miehei, has become extremely popular among home cheesemakers. It’s fully vegetarian, very consistent, affordable, and works beautifully for mozzarella, cheddar, feta, halloumi and most other cheeses. For long‑aged cheeses, some people claim there’s a slight difference in flavour compared to animal rennet, but for beginners and small dairies, the difference is barely noticeable.

So which rennet should you choose as a beginner? Most new cheesemakers find that liquid microbial rennet is the easiest and most predictable option. It’s simple to measure, dissolves instantly, and works for almost every cheese you’re likely to make at home. If you prefer something that lasts longer in the cupboard, microbial rennet tablets are a great alternative. If you’re aiming for traditional aged cheeses and want to follow classic methods, animal rennet is still widely used and respected.

Whichever type you choose, a few simple habits will help you get perfect curds every time. Dissolve tablets fully before adding them to milk. Avoid adding rennet to milk hotter than 40°C. Stir gently rather than vigorously, as too much agitation can break curds before they form. Use fresh milk whenever possible, and store your rennet away from heat and light to preserve its strength.

Choosing rennet doesn’t need to be complicated. Once you understand the differences, you’ll quickly discover which type suits your style of cheese making. Whether you’re stretching your first mozzarella or planning a batch of homemade cheddar, the right rennet will help you turn milk into something truly delicious.