How to freeze rhubarb

Why freeze rhubarb?

If you have a crown of rhubarb, you’ll be supplied all spring and summer, so if you don’t want to eat rhubarb all the time, freezing is a good option. Or, you may love rhubarb and want a supply through autumn, in which case buy when the price drops and freeze for later.

As the season progresses, rhubarb will get more fibrous, so take this into account when choosing how to freeze it – cooking it fully first might be a better option. One thing to note if you grow rhubarb is that the leaves can be toxic as they contain oxalic acid, so trim them off completely and discard.

You can freeze rhubarb raw, blanched or fully cooked. Regardless of which stage you choose to freeze at, the rhubarb will break down more as it defrosts, so it's best used in dishes where you don’t need neat sticks of it. Pies, crumbles, smoothies, fools and sauces for savoury dishes all work well with frozen rhubarb as it won’t matter if there's extra liquid. Avoid making cakes or muffins unless your defrosted rhubarb is very dry, or they may end up soggy.

How to freeze rhubarb raw

Choose crisp, firm stalks for this method.

Trim the rhubarb of stringy bits and cut into short lengths, if the stalks are very fat then cut them lengthways into pieces so they freeze more evenly.
For loose pieces of rhubarb, spread the pieces in a single layer on lined trays and open freeze them.
Once frozen, tip the pieces into containers or bags. Otherwise, if you are not worried about them sticking together, freeze them straight into the container or bags. Use within three months.

How to freeze blanched rhubarb

Blanch rhubarb in boiling water for 1 min, then scoop straight into ice cold water to cool immediately.
Drain really well and spread out on a clean tea towel to dry.
For loose pieces of rhubarb, spread the pieces in a single layer on lined trays and open freeze them.
Once frozen, tip the pieces into containers or bags. Otherwise, if you are not worried about them sticking together, freeze them straight into the containers or bags. Use within six months.

How to freeze cooked rhubarb

The simplest way to freeze rhubarb is to cook it gently first.

Stewed rhubarb

Tip the rhubarb into a pan with a little liquid (water or freshly squeezed orange juice work well), and add a sprinkling of sugar. Rhubarb can be quite tart so you may need 15-30g sugar per 100g rhubarb; start with 15g and add more later if you need to. You can also add other flavours, such as ginger, at this stage.
Simmer until it is completely tender, add more sugar at this stage if you need to. Cool completely, then freeze in portions in containers or bags.

Roasted rhubarb

Heat the oven to 200C/180C fan/gas 6. Trim and cut 500g rhubarb into little finger-sized pieces. Put in a shallow dish, sprinkle over 80g caster sugar, toss together, then arrange the rhubarb in a single layer.
Cover with foil and roast for 15 mins. Remove the foil and roast for another 5 mins or until tender and the juices are syrupy. The rhubarb should still have kept its shape. Cool and freeze in a container.

How to defrost rhubarb

To defrost, leave the frozen rhubarb out for several hours. If you want the pieces to keep their shape don’t move them around until they are full defrosted. Fully cooked rhubarb will break down even more as if defrosts.