Yesterday I re-listened to the MBAA podcast (ep.40) with Joe Formanek on gallotannin and beer stabilization. For FLAVOR stability, he recommends it at mashing in, where it will chelate "excess" iron and copper -- not all, just "excess," and just how much is not specified. So far so good. For COLLOIDAL stability, he says the ideal use is in the bright tank, but if your process won't accommodate, you can get some benefit with a late kettle addition.
In general we try to do the following (the "Royal We", i.e. LOB folks):
1.) Use a false bottom AND a mash bag for filtering;
2.) Use the recommended amount of BTB/Gallotannins in the mash;
3.) No Sparge with constant recirculation and evenly distributed return (usually LocLine circle flow) at the top
We typically are not using the false bottom for filtering, but more to lift the bag of the bottom of the kettle and provide maximum surface area for recirculation through the grain bed. The Brew bag has a fine enough mesh to actually to keep out very small bits of grain, lipids, protein materials, etc. Recirculation ends up setting a very nice grain bed that further helps with filtering. Then we runoff so we don't have to disturb it.
If using Antioxin SBT (10% gallotannins), we supplement with additional BTB up to the manufacturer's recommended value.
If you read some of the literature on gallotannins in beer production, you'll see it drops out certain protiens in all stages where they can form haze, i.e. mash, kettle, KO, etc.
This is from
"Upstream Beer Stabilisation during Wort Boiling by Addition of Gallotannins and/or PVPP" by Withouck, Boeykens, Jaskula, Goiris, De Rouck, Hugelier, and Aerts:
From Abstract"The lowest gallotannin levels (wort boiling: 5 g/hL; contact time in boiling kettle: 3 minutes) are already sufficient to obtain enhanced stability due to adequate removal of haze-sensitive proteins. Lowering pH at mashing-in also results in improved physico-chemical properties and flavour stability."
From Introduction"Interactions between haze active polyphenols (proanthocyanidins) and proteins can result in irreversible bounding which has a negative impact on the "shelf life" of beer. Also, polysaccharides, metal ions and minerals can be responsible for the forming of haze.The composition of the raw materials is a first important parameter. During
mashing (emphasis added), wort boiling, fermentation and maturation, haze can be formed and removed. The pH is critical in obtaining maximum protein precipitation.
To improve hot break removal after wort boiling, the pH of the wort should be between 5.0 and 5.2 (emphasis added because this is something we do at the 10 minute mark).
Gallotannins are known to act as radical scavengers, metal-chelating agents and
anti-oxidants (emphasis added to highlight that this isnt in the active sense, i.e. sulfites, but in the removal of compounds that can participate in oxidation reactions).
Besides these characteristics they are also very effective in coagulation and flocculation of thiol-containing proteins (emphasis added, more in a moment)."
I am having trouble pulling some Bamforth snippets that talked about the removal of foam negative thiol-containing proteins, so when i find them i'll post them here.
Long story short: I think the way to improved stability is process based AND can be helped greatly by adding some form of gallotannins in the mash. We try hard to get good hot AND cold break in the kettle as well and remove ALL of it.
Clear beer into the kettle (as noted by the lengths we take above) leads to clearer beer into the the fermenter and is more stable for
US! (emphasis added because different strokes and YMMV), especially since we are in a complete low oxygen environment all the way to packaging, so trub and lipids and metals and bad proteins react very differently in a low oxygen environment. We tend to not even have to worry about colloidal stability issues following the above, so mostly we use gallotannins to drop out lipids and bad proteins in with the spent grains.
Also, I'm going back to using my tap water so i'll be using it to chelate iron, etc.
To wind back to the original topic after all of this, I think maybe i'll start bumping calcium up to 60 ppm instead of 40 ppm. I'm definitely keeping gallotannins in the mix.
Topic: Experiment tying some threads together (Read 10125 times)
