Beech Mast As A Food Source

The seed of the beech is known as mast. 2011 was a great year for Beech Mast on a couple of trees on my patch. As I watched the mast ripen my thoughts turned to the usefulness of this plentiful food source.

Note: The specifics of this article refer to the European or Common Beech, fagus sylvatica. Other beeches may vary!

Beech facts

Beech trees do not start flowering and producing mast until they’re quite mature – somewhere around 30 to 40 years old.

Individual trees go through cycles. Every three or four years they produce a bumper crop of mast. You won’t find mast on every tree every year.

Beech mast as food: The research

Separating fluff and mast

When it comes to wild food I’m always keen to see what other people say and then draw my own conclusions with some experimentation. Most wild food books are pretty sketchy when it comes to beech mast. I think their fiddly nature makes them rather unattractive to the casual wild foodie. For the dedicated forager or someone in need of some calories I felt there was a need to explore further.

A google search turns up a few discussions concerning the edibility of beech mast. They usually end up declaring it not worth the effort or just plain horrible. Armed with this rather unappealing view I set out to make up my own mind.

How to find beech mast

Beech trees flower from April to May, and the mast ripens from September to October. When the mast is ripe the prickly seed cases start to open.

You can easily tell when a tree is having a good mast year. Even from a distance you’ll see the branches drooping under the weight of the nutty goodness.

How to gather beech mast

There are a couple of options here depending on how much you need the nuts:

If you need calories and you need them before the squirrels then harvest the mast from the tree as soon as (or slightly before) they’re ripe. If the spiky cases haven’t opened yet, arrange them in the embers next to a fire for a few minutes. In my experience the heat opens them up.

If you can wait and it’s a good crop year then you’ll find the mast covering the floor under the tree once the husks have dropped their payload. In a bumper year the mast is so abundant even the squirrels struggle to hoover them up. I’ve got an idea they even get fed up with them.

While gathering you soon learn the best techniques and start to naturally get a feel for underweight or empty mast which can be discarded. After half an hour under a beech tree you’ll have a reasonable quantity of mast.

Processing and Edibility

Toasting the beech mast

Before eating any plant seeds and nuts, we need to think about the natural lifecycle of the plant and the measures it takes to protect future generations. Plants have evolved a number of ways of making sure their seeds are ingested to distribute them but pass through the eater without being digested.

One of the common compounds found in plants are tannins. Beech contains tannins and and the mast is reported to contain tannins.

Tannins are widely found in the bark of trees, insect galls, leaves, stems and fruit. They are are useful to us medicinally as they are the chief plant constituent responsible for astringency. They contribute a protective function in the bark and heartwood of trees and plants.

Tannins dissolved in water from nuts such as acorns, bark or leaves of plants containing tannin produces a mildly acidic and very effective antiseptic wash.

However, when eaten, some tannins aren’t as useful. They can act as a digestive inhibitor and cause reduced absorption of proteins and other nutrients. Tannins have a puckering, sour taste when ingested (if you’ve ever eaten sweet chestnuts or acorns raw, you’ll know what I mean!).

The reported tannin content in beech mast leads many people to write them off as a potential food. However, from my own experience I’m not sure that the nut itself does contain that much tannin. Maybe this varies from tree to tree.

Unprocessed I found the mast to be fine to eat. Maybe slightly astringent but quite palatable. In the past I’ve spent a few days with raw beech mast as one of my main foods and suffered no ill effect.

In sweet chestnuts the tannin is supposedly found in the soft skin surrounding the seed but not in the seed itself. I wonder if this is the same for beech mast. I found that after toasting the beech mast (which tends to make the “skin” flake off the outside) that the mast were actually very edible with a nutty flavour.

This improved them to the extent that I’d be happy to add a bit of salt and serve them for guests to nibble with a drink. This is at odds with what my research may have suggested. Yes, they’re fiddly to shell but if that’s the only negative are they worth the effort?

Is beech mast viable as a food source?

The little pile of handy looking fluff

The stats:

• I gathered 162g (5.71 oz) of beech mast for my experiment.

• It took me about half an hour to gather this quantity from the ground under the tree.

• I shelled 110g (3.88 oz) of this before all my fingernails fell off (an occupational hazard of the beechmast harvester).

• The shelling took a little over one hour.

The product of this was:

• 63g (2.22 oz) of nut meat

• 47g (1.66 oz) of shell

• A little pile of handy-looking fluff (just like the fluffy stuff in sweet chestnuts if you’re familiar with them) which I removed from the shelled nuts by shaking them in a bag.

Nutritionally speaking

From the USDA nut data website:


The amount of mast I collected would yield a gnats whisker off 100g of actual nut (i.e without shell). Add on maybe another half an hour to shell the remaining mast (and the cost of a manicure) and you’d have 576 calories for two hours of easy work.

I think this makes beech mast a viable food source despite what you might read or think when you start shelling the little buggers.