1 Brewhouse Operations I Influence on yield and quality main influences of the milling process, mashing main influences of the milling process, mashing and on yield, colloidal stability, microbiological stability, foam and flavor stability Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
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Brewhouse Operations IInfluence on yield and quality
main influences of the milling process, mashingmain influences of the milling process, mashing and on yield, colloidal stability, microbiological
stability, foam and flavor stability
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
Malt Analysis2
Incoming goods inspection (just after delivery/before unloading)
Complete analyses to check the stipulated quality(high time need, approx. 6 h)
Chemical technical analyses (moisture extract modificationChemical technical analyses (moisture, extract, modification, nitrogen compounds (proteins and degradation products),
colour, pH, viscosity, DMSP)
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
Sensory Analysis3
• Odour
The odour should be according to the type of the malt (more or less aromatic, fresh and pure)
• Taste and aroma
Pale malt: sweet and mealy. Dark malt: aromatic, a burnt and coffee-like taste is undesirable (depending on beer style)
• Colour and brilliancy
Colour and brilliancy should be uniformly pale or yellow-coloured and pure.
• Purity
The malt should be free from any pollution.
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
Further Analyses with Congress Wort
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y gpH-value
The pH represents the different malt acidities due to seasonal differences. For many breweries have their own water treating plant, they can indirectly influence the mash-pH. It is not useful to specify the pH-value. The pH-value may influence many other analyses due to its effect on the activity of the malt enzymes, therefore this analysis belongs to a standard analysis program.
Colour
The colour of the unboiled congress wort correlates relatively bad with the colour of the beer. Therefore, a specification is not necessary. For a pilsener malt, the colour should not be higher than 4 EBC units, sometimes the specification g , pdemands 3,5 EBC as the maximum value.
Boiled wort colour
The determination of the boiled wort colour gives us relatively good information on the colour of the final product beer. For a pilsener malt, the specification is normally 7 EBC as the maximum value.
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
Nitrogen Determination
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g
The determination of the nitrogen contents respThe determination of the nitrogen contents resp.the different protein fractions in barley, malt, wortand beer is of significant importance, because:
The protein content of barley correlatessignificantly negative with the extract content.g y g
Barleys with a higher protein content are harderto handle during the malting process higherg g p glosses.
Certain nitrogen fractions in wort and beer areCertain nitrogen fractions in wort and beer areresponsible for foam, yeast nutrition and non-biological stability.
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
Soluble Nitrogen
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Soluble Nitrogen
Soluble nitrogen and Kolbach index
The concentration of soluble (malt-) nitrogen should neither be too high nor too low. The range is between 650 and 750 mg/l in congress wort. In the case, that the values are too low the proteolysis of the malt is poor This canthat the values are too low, the proteolysis of the malt is poor. This can influence the fermentation speed and the growth of the yeast cells during fermentation; it has to be expected are possible changes of the aroma profile of the beer for example with regard to an increase of higher alcohols andof the beer, for example with regard to an increase of higher alcohols and diacetyl. In the case of a very high content of soluble nitrogen, there are nearly no changes in the aroma profile but influences the beer’s palate fulness and head retention.
The Kolbach index is defined as the ratio between soluble nitrogen and total nitrogen, expressed in percent. This index is a measure of the protein breakdown, by which a very good statement on the proteolysis of the malt is possible as long as you consider the total nitrogen content. Normal range beween 38-43 %.
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
DMS IN MALT
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DMS IN MALT
Formation of Dimethyl sulphide (DMS)y p ( )
S-methylmethionine formed by protein degradation y p gduring germination
Thermal degradationOf SMM during kilning
Dimethyl sulphide (DMS)
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
Recommended Specifications
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Malt analysis Specifications
European crop 2-row spring barley malt
Malt analysis SpecificationsMoisture % max. 5.0 Extract fine (d. m.) % min. 80.5 Colour of wort EBC max. 4.0Colour of boiled wort EBC max. 6.0 pH 5.85pH 5.85Viscosity (8.6 %) mPa*s 1.50 – 1.60 Saccharification time min max. 15 T t l it (d ) /100 1 9Total nitrogen (d. m.) g/100 g max. 1.9Total protein (d. m.) g/100 g max. 12.0 Soluble nitrogen (d. m.) g/100 g 0.65 – 0.75g ( ) g gSoluble protein (d. m.) g/100 g 4.0 – 4.7 Kolbach index % 36 - 42
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
Recommended Specifications
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M lt l i S ifi ti
European crop 2-row spring barley malt
Malt analysis SpecificationsFriability % min. 80 Whole kernels % max. 3Whole kernels % max. 3Turbidity (20 °C) EBC max. 3 (FTU 138)Sieving test: 2.8/2.5 mm % min. 80 Sieving test: < 2 5 mm % max 2Sieving test: < 2.5 mm % max. 2Grading: rejects % max. 2 Grading: dust % max. 1 Share of other barley varieties % max. 10Diastatic power °WK min. 220* DMS-Precursor ppm max. 5DMS Precursor ppm max. 5Calcofluor (modification) % min. 90 * 6-row min. 350
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
turbidity/ hot trub after whirlpool (< 70 mg/L)turbidity/ hot trub after whirlpool ( 70 mg/L)
Thiobarbiturate index (TBI)/ rate of thermal impact ( pale wort,Thiobarbiturate index (TBI)/ rate of thermal impact ( pale wort, beginning of boiling < 22; pale castwort < 45; pale wort after cooling < 60)
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
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Definition of Mashing
A mixture of malt grist and water at defined temperatures
Dissolve malt contents
Transformation of malt contents
With the purpose:p p
Starch degradation to sugars and soluble dextrines by enzymes
With the aim:With the aim:
To form as much extract as possible in a short time and a simple way.
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
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Processes During Mashing
• Solution of compounds
• Degradation of compounds• Degradation of compounds
– Starch degradation
Protein degradation– Protein degradation
– Gum degradation
Phosphate degradation
If necessary, depending on malt quality
– Phosphate degradation
• Minor reactions
C l f ti– Colour formation
– Minerals
O id i– Oxidation
– etc.
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
Optimum for formation of extract 5.2 Optimum for saccharification 5.5 Optimum of lautering according to Hopkins and Krause 5.5 Minimum of viscosity 5.0
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
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Extract Yield at Various Mashing Temperatures depending on pHdepending on pH
– poor malt qualities are hard to compensate !!!• mashing procedure:
– proteolytic enzymes are inactivated > 70°C
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
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Protein DegradationProtein Degradation
• Extract in Malt app. 80% app. 70% carbohydrates
app. 3.7 % proteins
• Influences:– Temperature: emphasize on 60-70°C increased levels of high
molecular nitrogenmolecular nitrogenemphasize on 45-55°C increased levels of
Formol-N and FAN decreasing the mashing in Temp. increase of total-N, Formol-N, and FAN
– Time : increased levels of degradation products with increasing time
– pH: increased levels soluble-N with lower pH-levels
– Concentration: higher concentration of mash leads to increased levels of low molecular nitrogen enzyme
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
levels of low molecular nitrogen enzyme treatment
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Degradation of β-glucansDegradation of β glucans
• One fundamental characteristic of -glucan formation of gel
• Initial stages of this gel: -glucan- associates depend on
-glucan concentration
h the temperature,
time
h i l b d f th t mechanical burden of the wort
• The -glucan from the endosperm of barley has, formed to gel, negative influences on viscosity and the filtration of beer.g y
• During germination -glucan degrading enzymes are effective by biogradation which convey the high molecular extended forms into snarled formssnarled forms.
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
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Degradation of β-glucansDegradation of β glucans
• Decisive: malt qualityDecisive: malt quality
• Disadvantages of an insufficient malt modification are not correctable during mashing:
– Decoction mashing: temperature of residual mash endo-ß-glucanase still active
L i f H d f l bi ti it i– Lowering of pH: decrease of solubiase activity, increase of endo-ß-glucanase activity pH 4,5
• A carefully directed degradation of cell wall substances at y g37°C-52°C helps to remove a part of them from the mash
Craft Brewers Conference 2015, Portland, OR VLB-Berlin; B.H.Meyer
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Phosphates and Buffer CapacityPhosphates and Buffer Capacity
• free phosphates react in the mash and form buffer substances• free phosphates react in the mash and form buffer substances
• –HPO42- and H 2 PO4 - are able to catch large quantities of H+ -
ions in the areas of the buffer
• act without influencing the pH value of the solution
• to lower the pH- value the buffer capacity must be reduced