Copper finings are derived from seaweeds and the active ingredients are carrageenans and furcellarans. They are available as dried seaweed, e.g. Irish Moss, or as extracts in the form of either pellets or powders.
Copper finings can be added directly to the copper. Alternatively powders can be slurried with cold liquor prior to addition.
The optimum rate of addition of finings should be determined annually when starting the new season’s malt or whenever there is a change in the type or supplier of malt.
The rate of addition of finings will affect the clarity of both hot and cooled wort. Incorrect addition of copper finings (both over and under) can give poor fining action in the cooled wort and beer which fines with difficulty.
Range of Values
Optimum rates of addition may vary from one malt variety to another, from season to season and from brewhouse to brewhouse. Murphys are happy to offer an annual optimisation service to our customers, either in our labs or on-site.
Typical rates of addition are in the order of 1·0 – 5·0 gms per Hectolitre (10 ppm to 50 ppm, 1·63 – 8·15 gms per barrel).• Hot breaks should consist of large flocs in bright wort. Cold breaks should be a heavy fine sediment in bright wort.
The haziness of worts from the heat exchanger should be within the range of 2 – 6 E.B.C. haze units. If worts are too bright fermentation problems are sometimes encountered because the release of carbon dioxide and consequent ‘stirring action’ that such a release promotes, are hindered.
When casting to a hop-back, finings are added during the last 5 to 15 minutes of boiling. If the practice is to recycle worts at the hop-back finings can be added at this point. When using a Whirlpool, finings should be added at casting from the copper.
Whatever method of addition is used the copper finings must be evenly dispersed.
Rates of addition should be optimised according to results obtained.
The formation of hot breaks is assessed visually after sampling from the copper at casting.
Cold breaks are assessed visually after sampling from the cold wort mains and allowing to stand for a minimum of 2 hours.
Rate of addition of finings; a graph is drawn of casting, gravity against rate of addition of copper finings and breaks are indicated as excellent, good or poor. The rate of addition is altered when poor results are observed.