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Is Adnams beer suitable for vegetarians? Fergus explains...

By Fergus Fitzgerald, also posted in News on

Fergus looking at the brightness of beerMy hiatus from blogging has been abandoned following a request to explain about finings and the ‘vegetarianness’ of such things. We use isinglass as a fining agent which basically means that the majority of our beers are not suitable for vegetarians, so I thought I’d explain what finings are and why we use them.

The main purpose of any finings is to help remove organic material from a liquid by speeding up the rate at which the organic material sediments out. The organic material we are trying to remove in beer is mainly protein and yeast. The main reason for wanting to remove some protein and yeast is that we want our beer to be bright, also too much yeast will also affect the flavour. Bright beer is not always an indicator of quality, but for the majority of people it still is. There was a time when the main cause of hazy beer was that the beer was infected and so for many people the connection between the two has been cemented. If I’m served a cloudy beer I always try and let the taste, rather than the clarity of the beer, be my guide. However, as brewers, if we tell you it’s going to be bright then that’s what it should be. I do think though that the invention of glass drinking vessels has a lot to answer for here, pewter mugs were a lot more haze friendly. Most finings act by electrostatic charge. The fining has a charge, either positive or negative, and attaches to material with an opposite charge. Once they are attached together, the material is larger and heavier and usually has no charge, so it will settle out of solution quicker than it would do by itself. A quick look up of Stokes Law will help to explain this bit. If used properly the finings should never actually end up in the finished beer as it will be in the sediment at the bottom of the fermentation tank or the cask.

How we use finings

We use finings at three stages of the brewing process.

  • The first stage is in the kettle, towards the end of the boil. These finings can be called kettle finings, copper finings or seaweed finings. The later name is because the finings commonly used at this stage are made from seaweed, the first name is fairly self explanatory, while the name copper finings derives from kettle also being known as coppers due to the fact they were historically made of copper. At the end of the boil, a lot of larger proteins will have come out of solution and will drop out by themselves but there are some smaller molecular weight proteins that won't drop out. We add the seaweed finings at the end of the boil and they attach to these proteins, become heavier and then sediment out.
  • The next stage when we add finings is at the end of fermentation. This is a silicate finings (given that the beach is one minute's walk from the brewery, our finings supplier took great delight in telling me that it’s basically just sand). This finings does two jobs, it helps to remove some more small proteins that might cause a 'chill haze' and it also helps to make sure all the particles remaining in the beer are strongly negatively charged which then helps when the final lot of finings are added.
  • The final finings that we add is to help the yeast settle out. We need yeast in the cask beer to help it condition and mature but generally we don’t want too much yeast left in the beer when its actually drunk. So we add some finings to help pull the yeast out. This finings has the opposite charge to the yeast and helps the yeast to drop out within a reasonable time. This finings is called Isinglass and is a protein made from the swim bladders of certain fish. The only alternative finings currently available is gelatine which is less effective and not really any improvement if you are worried about the beer being vegetarian.

Adnams brewer Robert Porter looks at the brightness of beerWhile it may seem odd to us now, there was a time, thankfully long ago, or as my son says ‘in olden times’ (by which he means 6-years ago) when bladders and swim bladders of various animals were used as vessels. We suppose that some clever spark noticed that beer and wine stored in these vessels was clearer.

All the above process applies to our bottled beer as well as the cask beer. There are a couple of bottled beers that don’t normally have Isinglass added but I would never say they were suitable for vegetarians as there may be occasions where we need to add isinglass if we find the yeast count is too high at the end of fermentation.

Using isinglass for beer destined for bottling is not the norm at most breweries but our bottler’s system is set up in such a way that they have to, and as above, even if they didn’t do it as a matter of course there may be occasions where they might need to.

Is there an alternative to Isinglass?

Robert and Fergus examine beer for brightnessThere have been attempts in the past to find a vegetarian alternative and we have trialled a few, but so far we haven’t found one that works for us.

In theory, gravity alone will eventually cause the yeasts to sink. Our particular yeast would require a substantial amount of time for gravity alone to make it all drop out. Some yeast strains will be quicker, although it would still mean a huge increase in the space a pub would need to store their cask beer. The extra time needed for the beer to drop bright would also mean that the beer would have very little time between when it was bright and ready to drink and when the best before date would expire. Of course, some of this extra settling time could be done at the brewery, but again that would necessitate a huge increase in the number of vessels needed.

However, if we still wanted to produce cask beer that actually conditioned in the cask, i.e. still had yeast in it, then we would still need to add some finings, or find a pub that could 'stillage' the cask for an extended period of time.

The other alternative is that we serve the beer cloudy. There is nothing necessarily wrong with this but excess yeast will affect the beer’s flavour, but probably more importantly most people expect it to be bright. There are a few breweries attempting to change the perception of cloudy beer, particularly Moor Brewing but there is some way to go yet.

I’m not vegetarian but my wife is, in large parts of my life that also makes me one, so I will keep looking at alternatives, but in the meantime I am quite glad that someone a long time ago liked to carry around their beer in a big old bladder, I only do that now after I’ve drunk it.


Fergus Fitzgerald