Category Archives: Frequently Asked Questions

What should you expect from this year’s malt specifications?

We’ve been discussing the expected malt specifications for the coming year with our malt suppliers and wanted to feed back so you can prepare and tweak your recipes as required.

The malt nitrogens coming into breweries with the new seasons malt are likely to be higher than usual, at around 1.7%. The winters are not expected to be quite as high, but are still above average, predicted at up to 1.5%. This is a result of environmental factors, as last year saw low rainfall which made it harder for the barley to establish properly. Blame the British weather, it’s a national habit and we brewers are no different. You can however, prepare for this and if you need any technical support in doing so, we’re always on hand. The key implications revolve around your use of copper and auxiliary finings, the rates of which will need to be reoptimised once malt is in breweries and will likely increase. You can expect to see the first malts of this harvest in breweries across the country from mid-February onwards.

Could do with a bit more information on the matter? No problem!

It starts with the farmers, who sow different varieties of malting barley in autumn and early winter, known as “winters” and again in spring, known as “springs”, both of which are harvested from early July onwards. The latter are becoming more popular as they tend to be easier to grow but do require more fertiliser to get a decent yield by harvest time. Winters don’t require as much fertiliser making them cheaper for the farmer but extract value to the brewer tends to be less.

In brewing, we refer to the percentage of protein present in the malt as percentage nitrogen, it is quoted on malt analyses and used as a price guide and quality indicator. For example, feed barleys have a high protein content to feed the animals. Brewers however, want nitrogens to be lower, at around 1.4-1.5%. This provides enough yeast growth, flavour and beer foam without any substantial problems with haze, stability and excess yeast growth, above these levels and the later can become an issue. There is therefore, always a focus on this parameter at harvest and purchase time.

How come the percentage nitrogen is predicted as being higher in British malt this year?

The issue is in fact that of last year, where we saw a prolonged dry winter and spring in the main growing regions of the UK, resulting in crops not establishing well. To help crops along, farmers spread higher amounts of fertiliser which in turn pushed the nitrogens up. This is because the fertiliser is taken up by the growing plant and deposited in the developing ears of corn which are the grains harvested as barley for the malt crop. Had they not done this, the crop may well have failed altogether, something which did happen in a small number of districts resulting in some shortage too. The maltsters work with what they get off the fields, blending barleys to get an overall consistency which they can sell to brewers. However from a brewer’s perspective, with already high nitrogens and a limited supply, the quality of malt coming onto the market is weaker when compared to the previous years’ crop. Therefore, the forecast is less stable beer.

As brewers there are various techniques at our disposal to control protein (nitrogen) in the brewing process, and this is where we at Murphys specialise! Carrageenan and auxiliary finings are both process aids that remove this protein. It follows therefore, that brewers will require more of these products to treat the higher nitrogen malt expected this year. Something which we can support with our optimisation services and technical expertise, provided to you by a team of master brewers. Choosing Murphys will be an invaluable decision in 2018.

Like to perform your own optimisations? We’ve just the kit you need!

The Murphy Copper Finings Optimization Kit, which contains all the equipment required, as well as documentation on how to perform your own optimisations.

Kegging, canning or bottling? Have you considered the benefits of Murphy’s Super F?

Since its launch,  Super F has proven invaluable to many of the top craft breweries worldwide, providing great results for beer produced for keg, can and bottle whether filtered or unfiltered.

What is it?

Super F is a rapid action fining, made using our own special formulation of silicate and polysaccharide for rapid sedimentation.  This unique blend makes Super F effective at fining out yeast as well as being an effective finings agent against potential haze forming colloids like proteins.

How’s it used?

Super F is best added when beer is moved from fermenting vessel to conditioning tank with care taken to ensure good mixing.  It is not a suitable addition for cask conditioned beer and should never be dosed directly to cask.  Action of this fining is quite rapid with excellent results achievable within 48 hours.  Super F packs a real punch so dose rates are low with typical doses 75ml-175ml per hl will achieve great clarity (often less than 1 EBC) and a compact sediment.

Benefits

The rapid action of Super F will significantly reduce residency time in conditioning / maturation vessel.  When using this product, the load on centrifuges and filters will be significantly reduced due to brighter beer being presented for further processing.  This gives considerable time and money savings per run.

When kegging unfiltered beer, yeast counts and protein content in the product will be lower and more consistent, leading to a more stable product.

Super F is also vegan friendly and is easy to store (just don’t freeze it!) with a shelf-life of 6 months from manufacture date. Furthermore, Super F is also in accordance with German Purity Law (set into force by the German provisional beer law in its current version 9 [6]).

Finings trials

Introducing a new finings regime to any brewery is a big step.  At Murphy and Son, we pride ourselves on our technical support so before any brewer uses this product we ask that they send a representative two litre sample of their beer to our laboratory where our Research and Development Scientist Dr Ruth Newby and the rest of the lab team will set up optimisation trials.  This will give valuable information on haze and sediment levels for different dosages to provide a starting point for trials and additions in the brewery.  As always, our technical sales team will also be on hand to aid and advise on the products use.

Author: Iain Kenny
Technical Sales Representative

For further information or to setup a trial please contact our technical team on
technical@murphyandson.co.uk

Christmas opening hours and deliveries at Murphy & Son

When’s the last time I can order before Christmas?

The nights are drawing in and the mornings becoming crisp and cold, which can only mean one thing Christmas is fast approaching! So, we thought we should let you know our Christmas opening hours and delivery times, to allow you to prepare.

Opening times (we do not open on weekends)

Date Opening Hours
Friday 22nd December 2017 9am-12pm
Monday 25th December ‘17 Closed
Tuesday 26th December ‘17 Closed
Wednesday 27th December ‘17 Closed
Thursday 28th December ‘17 Closed
Friday 29th December ‘17 Closed
Monday 1st January 2018 Closed
Tuesday 2nd January ‘18 Open as usual, 9am-5pm

Delivery Times

Date Order Placed Earliest Delivery Date
Monday 18th December 2017 Thursday 21st December 2017
Tuesday 19th December ‘17 Wednesday 3rd January 2018
Wednesday 20th December ‘17 Thursday 4th January ‘18
Thursday 21st December ‘17 Friday 5th January ‘18
Friday 22nd December ’17
(Closed until 1st January 2018)
Friday 5th January ‘18
Tuesday 2nd January 2018 Friday 5th January ‘18

Collections before and after the Christmas Break

  • To collect before Christmas you must order by 4pm Monday 18th December and collect by Wednesday 20th December.
  • Orders made after the 18th Dec can be collected from Wednesday 3rd January 2018 at the
    earliest.
  • Please call us on 0115 978 5494 to organise your collection as normal.

All orders placed online during our Christmas closure will be processed on Tuesday 2nd January and delivered from the 5th January 2018 at the earliest.

Please bear in mind that our order line will be closed during this time (12pm Fri 22nd Dec 2017 – 9am Tues 2nd Jan 2018), so we recommend waiting to order until our return (Tues 2nd Jan ‘18).

To speak to one of our team about this information or regarding another subject, please refer to the contact details listed here.

Many thanks, and here’s to a record breaking Christmas!

The Murphy & Son Team

IONIC COMPOSITION – Brewing Liquor

Originally, brewing started up in areas where the water supply was suitable for the production of beer, but with the wide geographical spread of modern breweries and modern supply systems, the water available to the brewer can be at best variable and at worst quite unsuitable. The natural water in areas such as Burton-upon-Trent proved excellent for production of bitter ale beers and many brewers will now treat their incoming supply to adjust pH and salts content to emulate Burton water. Where dissolved salt levels are low, it is usually sufficient to make up the concentrations to the desired levels. The most important ions are calcium (Ca++), sulphate (SO4–), bicarbonate (HCO3-), and to a lesser extent magnesium (Mg++), and chloride (Cl-).

CALCIUM (Ca++)
Calcium is a very important constituent and performs a number of functions:-

  • Decreases the pH during mashing and wort boiling, favouring enzyme activity
  • Promotes the precipitation of unwanted proteins in the kettle, hop back or whirlpool
  • Promotes yeast flocculation at the end of fermentation
  • Promotes head retention on beer
  • Reacts with oxalate to form an insoluble salt, preventing gushing in beer

SULPHATE (SO4–)
Sulphate is added to give beer a drier and more bitter effect

BICARBONATE (HCO3-)
Bicarbonate has the opposite effect to calcium in that it causes an increase in pH, so reducing the desirable effects of calcium

MAGNESIUM (Mg++)
Magnesium levels are typically rather lower than calcium and in addition its salts are more soluble,
so it has less effect on pH and flavour than calcium

CHLORIDE (Cl-)
High chloride concentrations are not usually found in water; its addition can impart palate fullness

WATER HARDNESS
Both temporary and permanent hardness can be treated using acidic products

WATER HARDNESS
The presence of calcium or magnesium ions in water gives rise to hardness, the familiar effect of which is to diminish or prevent the formation of soap lather. Calcium (or magnesium) bicarbonate in water is termed temporary hardness, so called because it can be removed simply by boiling the water and precipitating insoluble carbonate together with the evolution of carbon dioxide. Calcium or magnesium salts other than bicarbonates, typically sulphates or chlorides, are termed permanent hardness because they cannot be removed by boiling. Instead, other treatments such as sequestering, ion exchange are used.

Acid Treatment
This is now the most widely used method, for a number of reasons:-

  • It is relatively inexpensive
  • It is easy to use and does not produce sludge in the hot liquor tank
  • Products such as AMS will add desirable anions, sulphate and chloride
  • It can be achieved by using products such as Phosphoric Acid or Lactic Acid if no anions arewanted – for example in lager beers

It is essential to rouse the liquor when acid treating in order to encourage the removal of the carbon dioxide. This can have corrosive effects on the materials of construction of hot liquor tanks if left in solution.

Our Returnable Drum Service

We here at Murphy and Son are committed to operating a strict environmental policy to help reduce our carbon footprint. As part of this, we operate a returnable drum service. 

Alongside helping protect our planet, our returnable drum policy allows you to avoid the time consuming and often expensive process of disposing of drums and IBCs personally. We are always happy to collect your empty Murphy & Son drums and IBCs from your site, simply agree a date and time with our team by calling sales on 0115 978 5494.

To cover the cost of supplying and transporting our containers throughout the UK and to allow for damaged containers and the process of laundering, label removal, cap replacement and micro swabbing, we do charge a small fee per container. The majority of this fee is credited back to you upon receipt of your returned containers.

A full break down of any and all costs of this service can be found below.

Container size and type
Charge per container
Refundable amount per returned container
Non-refundable carriage charge per container
25 litre drum £5.83 £4.73 £1.10
200 litre drum £20.70 £18.39 £2.31
600 litre IBC £111.42 £105.08 £6.34
1000 litre IBC £201.63 £183.90 £17.73

There are also a few other conditions of service we’d like to tell you about.

  • All containers must be returned in a rinsed, clean and sound condition.
  • To comply with Food Standards, we ask that nothing except the product we supply is stored in said container. Contaminated containers will be refused return and/or refund.
  • We only except returns within 12 months of purchase.
  • Please stack any empty containers on a pallet and wrap ready for transportation
    We’re happy to provide a roll of shrink wrap for this purpose, just give us a buzz to request.
  • We only accept containers supplied by Murphy & Son Ltd, other suppliers’ containers cannot be accepted.
  • This service is only available on the UK mainland

If any of the above conditions aren’t met, then we reserve the right to refuse refund.

Packing your drums ready for collection…

25 litre containers Palletise in a 4×4 layout, minimum of 2×16-32 units and no more than 4 drums high, a total of 64 units
200 litre containers Palletise a minimum of 2 containers with a maximum of 2×4 per pallet, a total of 8 units
If the number of containers you use is very small, we will accept a pallet with less items if this is pre-agreed and within the required 12 month return time.

We’re committed to ensuring the quality and efficiency of this service, therefore if you have any questions please don’t hesitate to get in touch via info@murphyandson.co.uk or by calling our Sales Team on 0115 978 5494.

Thank you from all the Murphy & Son team, for your continued custom and helping us do our bit for the environment.

Happy brewing!

Addition of Copper Finings Murphy and Son Ltd

General Considerations

• 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.

Operational Protocols

• 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.

Measurement Protocols

• 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.

Kettle Finings at Murphy & Son

Brewing Audit

Build up of Beerstone

NIPAC B  – Beerstone Remover

Corner-Technical

Beerstone removal

As a brewer you may have a problem with beerstone build-up in brewing vessels and containers.
Beerstone is a compound called calcium oxalate, and if not completely removed can harbour microorganisms. Beerstone is a common factor in wild yeast infections within breweries, it can also act as a nucleation point and cause gushing.
The removal of this material is carried out by using a concentrated formulation of nitric and phosphoric acids.

Nipac B is designed primarily for this application in breweries and is formulated to be low foaming and is suitable for use in recirculation applications. It can be used as an alternative to caustic based detergents in breweries for the cleaning of bright beer tanks and tankers whilst under CO2 atmosphere. A gel version exists for manual application where recirculation of the product is not possible.

https://murphyandson.co.uk/store/75-beerstone-removal

BENEFITS OF NIPAC B

· Excellent mineral and protein removal
· Aids removal of beer and milk stains
· Safe for use on Stainless Steel
· Can be used under CO2 atmospheres
· Suitable for use in CIP applications.
For more information and dosage rates please click on the following:
NIPAC B Technical Data sheet. Please contact our sales line or sales email to purchase this product.

logo_holchem

Hygiene from Holchem

Function of Auxiliary Finings

Auxiliary Finings

General Considerations
• Auxiliary fininqs aid the action of isinglass finings by enhancing the total negative charge, especially when contribution by yeast is low. This improves the electrostatic interaction between proteins and isinglass finings. Beers fine more quickly because of the larger floc size.
• Auxiliary finings are available in solution as acidified polysaccharides, silicates, alginates and formulated blends.
• Factors which need to be considered are the type of auxiliary finings, dosage rate, storage temperature and conditions, time of addition, fining performance, yeast count prior to fining and compactness of sediment.

Range of Values
• Sulphur dioxide content of liquid auxiliary finings is typically between 200 and 300 mg per litre.
• Solutions of auxiliary finings should be visually bright prior to use.
• Yeast counts are typically 0·5 x 106 – 2 x 106 cells per ml with a mean of 1·0 x 106 cells per ml.
• The dosage rate of auxiliary finings is typically 0·9 – 3·5 ml per litre (¼ – 1 pint per barrel), but is related to the isinglass dosage rate and depends on compactness of the sediment.

Operational Protocols
• Liquid auxiliary finings are stabilised with sulphur dioxide and stored in inert containers at ambient temperature There must be adequate ventilation in the storage area because levels of sulphnr dioxide particularly on delivery can be high.
• Addition is made in-line through a dosing pump as beer is transferred from fermenting vessel to racking tank or directly to tank or cask
• Addition of alginate auxiliary finings is made at least 4 hours before addition of isinglass finings. Due to the rapid action of silica based auliliaries they can be added either pre- or post-isinglass finings. The actual time of addition is determined by experience.

Measurement Protocols
• Every batch of finings should be inspected visually and examined for infection by micro- organisms.
• Fining action is monitored by making the equivalent addition of finings to appropriate samples of beer and noting daily the size of flocs, speed of fining action and clarity of fined sample
• A nine gallon cask is fined and stillaged in the sample cellar for a larger scale production check on the fining performance
• Finings contribute to sulphur dioxide levels in beer The levels of sulphur dioxide in samples of fined beer should be measured. Auxiliary finings supplied by Murphy & Son Ltd. will add in the order of 0·25 – 1 ppm SO2 to the beer at typical addition rates.

Take a look at our Auxiliary finings range

 

Water, Water Everywhere. Murphy and Son Ltd

Water, Water Everywhere

We take treating your liquor very seriously at Murphy’s. If you purchase any of our liquor treatments please remember you are entitled to a free liquor analysis and our technical support. We will recommend the most suitable treatment for your brewery.
Send in 50ml of your water to our Laboratory

Send in 50ml of your water to our Laboratory

Introduction

Beer contains approximately 90% water, and the importance of the liquor to final beer quality cannot be over-estimated. Historically a correlation was observed between the liquor composition of an area and the type of beer that the region could best brew. The Pale Ales of Burton-on-Trent and Edinburgh, Porters of London, Stouts of Dublin and Lagers of Pilsen are classic examples. Water falling as rain, hail, sleet or snow is pure, but dissolves gasses such as oxygen and carbon dioxide from the atmosphere. On reaching the ground the water runs off into rivers, streams and lakes and on in some cases to reservoirs. The composition of the water in the reservoirs is dependent upon the nature of the catchment area. In areas where the rocks are hard, the water will not penetrate deeply, and will be ‘soft’ – that is low in dissolved salts. In areas where the rocks are more permeable – gypsum obrewing liquorr limestone for example – water will penetrate readily and dissolve many minerals on its way to the reservoirs to become ‘hard’.

The water supplied by local Water Authorities is required to be potable – that is fit to drink and free from pathogenic organisms. In order to reduce microbiological counts chlorine will usually be added, but the water is not sterile. Fortunately however the micro organisms found in water are not beer spoilage organisms, being unable to survive the conditions of high ethanol and hop resin levels and low pH found in beers. So the objective of liquor treatment is to convert the water sent to us by the Water Authorities into acceptable brewing liquor. This we achieve by the removal of unwanted ions and addition of required levels of desirable ions

DWB Liquor Treatment from Murphy's

DWB Liquor Treatment from Murphy’s

Calcium

Of the ions required for brewing, calcium is by far the most important. This is because of the acidifying effect that calcium has on the wort.

Wort contains large amounts of phosphates derived from the malt, and these have a buffering effect – that is they tend to mop up hydrogen ions and keep the pH higher than desired. Calcium ions precipitate phosphates as insoluble calcium phosphate and release hydrogen ions into the wort. It is worth mentioning at this point that whilst the pH of the wort is critical, that of the water in the HLT is not. The pH of water may vary from about pH 5 to pH 8 dependent upon the levels of dissolved carbon dioxide – even de-ionised water can have pH levels as low as 5 after exposure to the air. However the carbon dioxide is driven off by heat in the HLT and the pH of the water will rise.

A combination of the presence of calcium ions and the decrease in pH has a number of effects on the brewing process:

The lower pH improves enzyme activity and thus wort fermentability and extract.

The optimum pH for ß-amylase activity is about 4·7. Wort produced from liquor containing no calcium has a pH in the order of 5·8 – 6·0, compared to values in the range of 5·3 – 5·5 for worts produced from treated brewing liquor. The activity of the ß-amylase then is greatly enhanced by the addition of calcium, this exo enzyme increasing the production of maltose from Amylose, and thus making worts more fermentable.

Calcium has an almost ‘chicken and egg’ effect in the precipitation of wort proteins, both during mashing and during the boil.

Protein-H + Ca2+ Protein-Ca + 2H+

The hydrogen ions released further reduce the pH which encourages further precipitation of proteins. Proteins are also degraded, that is converted to simpler substances by proteolytic enzymes called proteases. These are found in the malt, and have optimum activity at pH values of about 4·5 – 5·0. The reduction in pH then caused by the presence of calcium encourages proteolysis, further reducing protein levels and increasing wort Free Amino Nitrogen levels (FAN). FAN compounds are utilised by the yeast during fermentation for the manufacture of Amino acids, and an increase in FAN levels in the wort improves the health and vigour of the yeast. High protein levels in beers also have negative effects, making beer more difficult to fine and encouraging formation of hazes, in particular chill hazes. Product shelf life can also be adversely affected.

Calcium ions protect the enzyme a-amylase from inhibition by heat.

a-amylase is an endo enzyme, cleaving the internal 1,4 glucosidic links of amylopectin resulting in a rapid reduction in wort viscosity.

It can be seen then that the presence of calcium has positive effects on the activity of both a-amylase and ß-amylase, two of the most important enzymes in the brewing process.

The drop in pH encouraged by Calcium ions in the mash and copper helps afford the wort and subsequent beer produced a greater resistance to microbiological infection.

The reduced pH of the sparge liquor reduces extraction of undesirable silicates, tannins and polyphenols from the mash bed.

The extraction of such materials is encouraged by alkaline sparge liquor. These materials are very undesirable, contributing to harsh flavours, hazes in the finished beer and decreased beer stability.

Calcium precipitates oxalates as insoluble calcium oxalate.

This again occurs in both the mash tun and the copper. Oxalates cause hazes in finished beers and also contribute to the formation of beerstone in FV’s, CT’s and casks. Oxalates are also thought to promote gushing in certain beers, although this is not generally a problem to the micro brewer.

The presence of calcium reduces colour formation in the copper.

This is due to the reduction of extraction of colour forming compounds such as anthocyanogens and pro-anthocyanidins during the sparge. The reaction: Reducing Sugar + Heat Melanoidins is also inhibited.

Calcium ions improve beer fining performance.

Calcium ions encourage yeast flocculation – being a divalent Cation it has a natural affinity for negatively charged yeast cells.
With all the above advantages of the presence of calcium and reduction in pH there is one minor disadvantage.

The reduction in pH causes a decrease in hop utilisation, giving less bitter beers.

This increases hopping costs, since more hops will be required to achieve a desired level of bitterness. However the optimum pH for hop isomerisation as used in the commercial production of isomerised hop extracts is about pH 10, so a reduction from pH 5·8 in a mash with untreated liquor to pH 5·1 out of copper for a treated brew is not too critical.

You will see that much of the calcium added to the mash is lost – precipitated out as phosphate, proteinate or oxalate. Since calcium is specifically required in the copper for further precipitation of these materials it is common to add calcium to the grist or Hot Liquor Tank and to then make a second addition to the copper. Where this is not practical it is quite acceptable to make a larger addition to the grist or to the H.L.T.

Bicarbonate

This ion needs to be very closely controlled in order to achieve good beer. High levels of bicarbonate cause high pH values throughout the brewing process according to the equation:

It should be noted that bicarbonate ions are rather more effective at raising wort pH than calcium ions are at reducing it.
The conversion of bicarbonate to carbonic acid is reversible until heat is applied, which drives off the carbon dioxide. This effectively removes the acidic hydrogen ion from the system by using it to form a stable water molecule. The wort pH therefore remains high and all the advantages derived from the presence of adequate calcium levels and reduced pH are lost.

We therefore see the following:

  • Harsh after-tastes in the finished beer
  • Extract will be reduced due to lower ß-amylase activity
  • Reduced protein precipitation due to high pH
  • Worts and beer more prone to infection
  • Increased extract of undesirable materials in the sparge, notably silicates, polyphenols and tanning

The net result of this is then to decrease beer stability and shelf life and to increase the likelihood of troublesome hazes. Colour will be darker, and flavour will be detrimentally affected. Hop utilisation will be increased, giving more bitter beers. It is then essential to ensure removal of excess bicarbonate. You will recall from Figure 1 that a hard water may contain 250 mgs/l of bicarbonate. The maximum level that can be tolerated without adverse effect for the production of pale ales is 50 mgs/l, and the preferred level would be about 25 mgs/l. It should also be noted that whilst additions of calcium may be made to HLT, grist and copper, the removal of bicarbonate must be achieved in the Hot Liquor Tank.

This may be done in a number of ways:

Deionsiation: Very effective, but high capital and revenue costs.

Lime treatment: Addition of carefully controlled amounts of lime (calcium hydroxide) to the HLT will precipitate the bicarbonate as calcium carbonate.

There are 2 major drawbacks:

  1. The amount added needs to be exactly calculated and over addition may result in an overall increase in alkalinity.
  2. The precipitated calcium carbonate can form a sludge on the bottom of the HLT that will need periodic cleaning.

Boiling: This again is a traditional method of removal of bicarbonate (Temporary Hardness) but again has 2 drawbacks:

  1. Very expensive.
  2. Only effective where the alkalinity is present as bicarbonate. If the levels of sodium, potassium or magnesium carbonates or hydroxides present are significant boiling will not be effective.

Acid Treatment: Now the most widely used method, for a number of reasons:

  1. Relatively inexpensive.
  2. Easy to use and does not produce sludge in the HLT
  3. May add desirable anions – sulphate or chloride.
  4. Can use phosphoric or lactic acids if no anions are wanted – eg for lager beers.
AMS Murphy and Son Liquor Treatment

AMS Murphy and Son Liquor Treatment

It is essential to rouse the liquor when acid treating in order to encourage the removal of the carbon dioxide. This can have corrosive effects on the materials of construction of HLT’s if left in solution.

Magnesium:

Is an essential element of brewing liquor because it is required by yeast as a co-factor for the production of certain enzymes required for the fermentation process. It is invariable formulated into liquor treatments at relatively low levels.

However caution must be exercised for 3 reasons:

  1. Excess magnesium can interfere with the reactions of calcium because its phosphates are more soluble
  2. Above about 20 mgs/l magnesium can give beer a sour and bitter taste
  3. In excess magnesium has a laxative effect

Sodium:

Is present in all beers. Excessive levels are undesirable as it imparts a sour and salty taste at high concentrations. The flavour is more acceptable when the sodium is present as chloride than as sulphate.

Potassium:

Is, like magnesium, a yeast co-factor and is required at trace levels for satisfactory fermentations. It is more acceptable than sodium from a flavour point of view, giving a salty taste without the sour notes. It is also gaining some favour as Doctors warn of the effects of high sodium intake on blood pressure. However potassium salts are very much more expensive than the sodium equivalents, and in excess potassium has laxative effects on the beer.

Sulphate and Chloride:

It is convenient to discuss the effect of these two ions together. Much is made in brewing literature of the impact of these ions on beer flavour characteristics – sulphate gives beer a drier, more bitter flavour, whilst chloride imparts palate fullness and to an extent sweetness. However what must be noted is that it is the ratio of the concentrations of these two ions that is significant, rather than simply the actual concentrations. A ratio of about 2:1 sulphate to chloride is about right for a bitter beer, and it makes little difference if the actual values are 500:250 or 350:175 mgs/l. As will be seen in Figure 3 ratios of 1:2 sulphate:chloride are recommended for mild ales, whilst a ratio of 1:3 may give best results for stouts or porters.

Sulphate and Chloride: It is convenient to discuss the effect of these two ions together. Much is made in brewing literature of the impact of these ions on beer flavour characteristics – sulphate gives beer a drier, more bitter flavour, whilst chloride imparts palate fullness and to an extent sweetness. However what must be noted is that it is the ratio of the concentrations of these two ions that is significant, rather than simply the actual concentrations. A ratio of about 2:1 sulphate to chloride is about right for a bitter beer, and it makes little difference if the actual values are 500:250 or 350:175 mgs/l. As will be seen in Figure 3 ratios of 1:2 sulphate:chloride are recommended for mild ales, whilst a ratio of 1:3 may give best results for stouts or porters.

Sulphur is essential for the fermentation process, since the yeast needs to manufacture the two sulphur containing amino acids, cysteine and methionine. Some yeast strains will use sulphur from sulphate ions for this purpose and will then excrete any excess as sulphite ions. These can then be reduced to form hydrogen sulphide or sulphur dioxide. Both of these materials have characteristic pungent odours and even at low levels can give unacceptable sulphury noses to the beer. Bacteria also have the ability to produce a wide variety of sulphury off flavours, including rubber, garlic and cooked vegetable.

Nitrate:

Levels of Nitrate are beginning to drop generally due to greater control of the use of nitrogenous fertilisers. Nitrates themselves are not a problem at levels below 50 mgs/l, however they can be reduced by yeast or bacteria to form Nitrites. These ions can then react with wort amines to form Nitrosamines, which are carcinogenic.

Trace Ions:

Metals such as Iron, Manganese, Copper and Zinc may be found in small quantities in water and are all utilised by yeast at levels below 1 ppm. Higher levels can cause colloidal hazes and metallic off flavours, particularly with higher levels of Iron. Silica should also be at very low levels in brewing liquor because of the likelihood of colloidal hazes being formed. Ammonia should be absent in brewing liquors, being indicative of contamination by sewage. Fluorine, present in most waters at about 1 ppm for dental purposes, has no detectable effect on the brewing process. However Chlorine, used for sterilisation, may be at relatively high levels at certain times of the year. This can cause problems since chlorine is a very reactive chemical and will readily react with organics to form chlorophenols. These have a medicinal (T.C.P.) flavour which is in some cases detectable at levels below 1 ppb. Chlorine will be lost to some degree by the heat in the Hot Liquor Tank, but not all water used within the brewery is from that source. Some brewers may use untreated liquor to break down to gravity in fermenter, and rinsing following caustic or acid cleaning cycles will typically be with untreated mains liquor. One solution is to treat both Hot and Cold Liquor Tanks with 10 ppm of Salicon Liquid 169 (20 mls in 10 brls liquor) and rouse vigorously to remove the chlorine. The sulphur dioxide reacts with chlorine in the manner described below – reducing reactive, undesirable and potentially harmful chlorine ions to chlorides.



Typical Liquor Analyses for Beer Types:
Bitter Mild Porter Lager
Calcium 170 100 100 50
Magnesium 15 10 10 2
Bicarbonate 25 50 100 25
Chloride 200 200 300 10
Sulphate 400 150 100 10

Nitrate – As low as possible
Metals – Zn, Cu, Fe,Mn Less than 1 ppm All figures are in ppm (mgs/ltr)

ams200

AMS Liquor Treatment

Please take a look at Murphy’s Liquor treatment range.

 

Diacetyl Control: Using ALDC to brew the beer you intended

What is ALDC? Alpha acetolactate decarboxylase.

Benefits of ALDC:

·        Reduces Diacetyl production
·        Significantly reduces maturation times
·        More efficient vessel utilisation
·        Improves beer quality

Diacetyl is well known among brewers and beer drinkers – distinctive for its buttery aroma and flavour. It is both produced and removed naturally by ale and lager yeast strains alike during the course of a typical fermentation and many reliable house yeasts leave a little residual diacetyl in the finished beer. As such it is fairly common with many traditional and popular beer styles to contain some level of diacetyl in their flavour profile.

Murphy and Son has worked with a number of craft breweries in the USA and United Kingdom who wanted to produce modern, hoppy pale ales without any flavour of diacetyl, but that was brewed using their existing house ale strain of yeast. The concentration of diacetyl was initially monitored to see how it was being lowered by the breweries controlled fermentation and how effective the yeasts own ability to reabsorb and reduce the diacetyl during maturation was.

Murphy and Son analysed this beer for diacetyl levels in their laboratory in Nottingham, England. It was found that by applying ALDC to the wort at the same time as the yeast was added in a concentration of 3 to 4 grams per hectolitre, the flavour would be brought below threshold in the finished beer as desired (figure 1).

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ALDC is commonly used in lager production to lower maturation time, the rate-limiting step, by converting acetolactate (the precursor of diacetyl) to a flavourless end-product called acetoin. (figure 2 below).

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In this instance the ALDC was able to boost the diacetyl lowering effect of the yeast in the same way, culminating in the desired low concentrations of diacetyl in the finished beer and allowing the brewer to broaden the spectrum of beers produced without the need for another yeast.

As ale fermentations are much faster a little more ALDC was required than may be needed for lager, but at 3 to 4 grams per hectolitre of ALDC it was still found to be an economical solution to the brewer.

Murphy and Son Ltd sell ALDC in 1kg pack sizes!