A brief guide to Polypins and Firkins, FAQ

Milton Brewery sells beer in polypins and firkins. This guide will help you keep your beer fresher for longer.


What is a polypin?

A polypin is a 36 pint beer container. It is essentially a plastic bag with integral tap, held in a cardboard box. If you’re familiar with the “Stowells of Chelsea” wine boxes, think the same — but rather larger. The integral tap means no additional equipment is needed to serve your beer.

What is a firkin?

A firkin is a 72 pint metal cask. Most pubs take their draught beer in firkins. To serve from a firkin, you will need: a tap, a spile. Milton Brewery can lend you a tap & spile. There is a £100 deposit on a firkin, returned when we get the empty back.

What is ‘bright’ beer?

Bright beer is beer which has had the yeast sediment removed.

Why might I want ‘bright’ beer?

Bright beer can be moved without the danger of stirring up the yeast sediment. If you need to serve the beer within a few hours of delivery — order it ‘bright’.

Why might I want normal — or ‘live’ beer?

Beer with the yeast in suspension needs to settle (overnight will do). The yeast allows the beer to condition properly (as in a pub). Beer with yeast in it lasts longer than bright beer.

How long will my beer last?

It depends. Many factors affect the length of time the beer will be good for. Generally speaking though, cooler temperatures and stronger beers last longer. Beer in polypins lasts better than beer in firkins. At the time of writing -early October- live beer kept outside, in a shady place will last ten days in a polypin.

Can I make it last longer?

Yes. Easily. Once the beer is settled if you decant the beer into clean 2 or 3 litre plastic bottles, seal them, and place these in the fridge, they will last for up to a month (for our strongest beers). Typically, a consumer could store 3×3l in bottles, leaving 11 litres or 17 pints to drink from the polypin.

Why does beer last longer in a polypin than a firkin?

The bag in the polypin gradually collapses as the beer is drawn off, so air doesn’t get drawn in. The rigid walls of the firkin cannot do this, so oxygen is admitted and this will eventually cause the beer to go ‘off’

Why doesn’t Milton Brewery do smaller sizes?

We are a traditional brewery, supplying the vast majority of our beer to pubs. We believe this is the best way to enjoy beer. It also happens to be extremely good for the environment, minimising waste and packaging. Our license only permits us to sell beer in a minimum of 36 pints.

Why don’t you change the license in COVID-19 times?

We’ve asked. And the government says no.

How can I buy your beer?

See this page for details!