The Master Brewers
Association of the Americas has been doing podcasts and the recent
ones on malt specifications have been fab. Four podcasts where a
bloke rambles on about malt certificates of analysis, what's not to
enjoy?
Here's my notes on The
Best Four Malt Measurements:
Malting is about:
The Creation of enzymes
The partial digestion
of structures
The many ways in which
malts are analysed can be grouped into four bundles:
Bundle 1. Measure of
protein modification
Have insoluble proteins
been broken down into forms useful for brewing: for yeast food, for
foam and body (and also haze). Must be enough protein modification to
get to the beta glucan in the cell wall, otherwise beta gulcanase
can't work. Good protein modification is the low beta glucan enabler.
- Total protein and soluble protein less important than the ratio (SNR).
- FAN (Free Amino Nitrogen)
- pH reduces during modification, so well modified malts pH 5.8 to 5.9. Poorly modified greater than 6
- Alpha amylase can be measured here as it's not as affected by kilning.
SNR is the most
important
Bundle 2. Measure of
carbohydrate modification
Has there been enough
breakdown of endosperm and cell wall structure so is there
recoverable extract and consistent attenuation.
- Extract measurement
- Fine coarse difference (obsolete now, and very small)
- Viscosity (close to beta glucan in value, but differences too small)
- Beta glucan (proteins have to be broken down before beta glucans can so it's the last major modification event in germination). Often less than 120, less than 140 should be fine though.
Friability
Beta glucan is best
indicator of carbohydrate modification
If both protein and
carbohydrate modification are poor then poor extract, run off, haze,
attenuation, and filtration. Over modification makes thinner beer
with poor foam but over not as bad as under (like yeast pitching!).
Bundle 3.
Measurement of enzyme potential
Protein breakdown
should take place in the malting, and carbohydrate enzymes work in
the mash tun but must survive kilning.
(Enzymes
are more important for high adjunct lager)
As beta amylase is
more sensitive to kilning DP (Diastatic Power) is the most important
(though it will be in excess with all malt brews)
Bundle 4. Measures
of colour and flavour
[doesn't go on about
this, but presumably EBC (colour) and malt type – actually another
podcast is to follow: no number describes flavour, it's kilning
techniques. The numbers you have are EBC and moisture]
Friability: good
analysis if you don't have a wet chemistry lab. A functional analysis
of the whole malt system, instead of individual analysis of protein
and carbohydrate modification. A comprehensive view of modification.
SNR and beta glucan are
very variety dependent, so need to apply different values for
different varieties.
European (German/UK)
varieties have different values from US, as US historically had 6
row. So some need a higher SNR, there is no one correct SNR for all
varieties. Brewers may think 38-40, or perhaps 42 is best, but some
varieties may need 50. (People worry too much FAN means not enough
foaming protein left).
Variety (or varietal
blend) is important so the best SNR and beta glucan level can be
assessed.
Good friability
number with SNR defines good functionality of the malt.
Don't really need to
know total protein unless you want to reduce it so you can control
the amount of modification artefacts (i.e. too much soluble protein
or FAN) e.g. no malt with barley over 11.5%. Or use a variety that
converts less.
Need to look at
extract, not because it indicates quality of the malt but so you can
calculate yield.
Look at DP to check but
really you should have enough, more necessary with a higher kilned
base malt.
Kunze: In Germany (all
malt two row brewing) 75 DP. This is ample!
USA DP two row 140
In Europe FAN is 140 on
average
In USA is 220-240, so
again unlikely to be a problem.
Adjunct brewers use
standard pale base malt, craft brewers can us higher kilned base
malts which might have 90 DP.
Don't worry about alpha
amylase, unless you're an adjunct brewer. In Germany they don't even
list alpha amylase on malt analysis as it's not a problem due to its
abundance.
Least favourite
analysis is growth counts. Important in management of process but
means nothing in finished malt.
Cool post thanks for the link to the podcast, they are awesome too.
ReplyDeleteCheers! I wish he'd kept going, I can't wait to hear what he says about flavour.
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