Reducing sediment

One of the things that has bugged me has been the amount of sediment in my bottle conditioned beer. It isn’t unusual for there to be 3mm of sediment in the bottom of the bottle. There really isn’t anything wrong with this and it doesn’t affect the taste of the beer. However, it does put some people off. It also means that you need to be careful when pouring the beer to ensure avoid pouring into your glass!

Dry hopping the beer seems to create more sediment and some yeasts seem to produce a more “compact” sediment than others. I like to use Fermentis S-05 – it seems to clear quickly (2-3 days in the bottle) and produce a compact sediment that isn’t easily disturbed.

On the positive note, if sediment is dropping out of the beer during conditioning, it does produce clearer beer. But when I have looked at commercial brewer’s “bottle conditioned” beer there is almost no sediment in the bottle at all.

I think that I have finally got to a position where I have reduced the sediment to a small amount (less than 0.5mm) in the bottom of the bottle. It is often no more than a dusting of sediment in the bottom of the bottle. Here’s what I do:

• I add Irish Moss (a type of dried seaweed) to the last 15 mins of the boil when brewing the beer. This helps to connect the chains of protein together forcing it to drop out of the beer. Most of the seaweed gets caught in the filter in the bottom of the Grainfather and never makes it into the fermentation vat. I think this reduces the “haze” in the beer.
• At the end of the fermentation, I chill the beer before bottling. I chill it to about 4C for 48 hours. This causes the yeast cells to flocculate (i.e. clump together) and drop out of the beer. I have tried longer and shorter chilling periods, but 48 hours seems to work well for me.

Unfortunately, to be able to chill the beer you need the right kit. I am using conical Grainfather fermentation vats. These allow me to drop the debris out of the bottom of the vat during fermentation. These also have a “cooling jacket” built into the stainless walls. I am then using a gylcol chiller to reduce the temperature of the vat. The chiller is set to run at about -2.5C and this means that it cools the beer to about 4C. It will take 3-4 hours to go from about 23C down to 4C.

Initially, I thought commercial brewers must be filtering their bottle conditioned beer to remove the sediment. But this doesn’t seem to be the case with the craft brewers. In fact, filtering seems to be a bit of a dirty word! This might be different if you’re brewing massive quantities of lager, but not small batch craft ale.