my general understanding is that k- and na-mbs are relatively fast acting, while ascorbic is less so. Can someone chime in on any negative affects of using these as an addition along with dry hopping to combat o2 ?
Well aware of dry hopping with points left, as well as adding priming/yeast, etc. Not looking to do that tho. Just want to know if this can be done without adverse affects so close to packaging/serving.
I did this yesterday with the trifecta using Sodium Metabisulfate, Asorbic Acid and Brewtan-B.
Dropped 20mg, 20mg, 40mg into a liter of post boil water then poured it on an oz Citra cryo in my coffee press. Let it steep 10 minutes. Put in a 2ltr bottle. Used my carbonating cap and put 10psi on it. Next I inverted it to force it into my closed and purged keg. Popping off the disconnect just before it got to the air. Then did my closed transfer for my pale ale. It's spunding right now.
Everything below this are quotes from the web... More Beer and Northern Brewer.
https://www.morebeer.com/products/ascorbic-acid.html
Ascorbic acid is a quick-acting and powerful antioxidant that is used in white winemaking to protect against light and short aerations, such as racking and bottling. It works by rapidly converting dissolved oxygen into hydrogen peroxide before it has a chance to react with oxidative enzymes and cause browning. However, this hydrogen peroxide itself needs to be removed from the wine in order to avoid the very phenomenon that was trying to be avoided in the first place, namely oxidizing the wine. The answer lies in always making sure that the free SO2 levels are correct, both before the ascorbic addition is to be made and after. (Note that "Titrettes" are not accurate enough for this, and that a more precise means of determing free SO2 is needed, such as an Aeration-Oxidation set-up). Addition rate is around 50 mg/l (ppm) as long as the free SO is maintained at 30 mg/l (ppm).
A rough approximate of weight is 1 tsp = 3.2 grams. We highly recommend using a scale to weigh the product for an accurate dose. We do not recommend relying on these rough conversions for accurate dosage rates.
https://www.morebeer.com/products/potassium-metabisulfite.html
Potassium Metabisulfite, (often referred to as "SO2", "sulfites" "meta", or "meta-bi") has several uses in winemaking. At the crush, sulfites are generally used to help control the spoilage bacteria and indigenous yeast that may already be present both on the fruit and in the winery (i.e. on the picking bins, processing equipment, tanks, tubing, etc).
The amount generally used is enough to inhibit most of the unwanted organisms but not enough to hinder a cultured yeast, which has a higher tolerance to sulfites than most of the indigenous organisms do. This inhibition effectively "wipes the slate clean" for the cultured yeast to step in and rapidly colonize the must so that it can effectively dominate the subsequent fermentation.
In addition, sulfites also help to inhibit the enzymatic browning of both musts and finished wines so that all of their delicate complexities can be preserved. Later, during storage and in the bottle, sulfites at the proper levels will further protect a wine by continuing to inhibit spoilage organisms, as well as by scavenging oxygen.
Note that the exact amount needed to effectively do the job is determined by the pH of the wine. Refer to our MoreManuals! on Red or White Winemaking or one of the winemaking books that we offer for a complete explanation on how to properly manage sulfites.
In addition, it's important to keep in mind that free SO2 levels fall faster in wood cooperage than in glass or stainless, so if you are using a barrel you will most likely need to manage sulfite levels more closely.
The most common form of Metabisulfite is as a powder which is fixed with potassium or sodium. 1/4 tsp of Potassium Metabisulfite adds 50ppm to 5 gallons of must. Old Metabisulfite loses potency with time and should be replaced every year to assure that you are getting correct levels. You can use old Metabisulfite to make solutions for sanitizing equipment.
https://www.northernbrewer.com/products/sodium-metabisulfite-8-oz
Essentially the same salt with the same applications as potassium metabisulfite, but contains the sodium ion instead of potassium. Some winemakers prefer to use this salt for sanitizing and KMS for antioxidant/stabilizing additions to must and wine. Use the same way and in the same proportions as KMS.
http://wyeastlab.com/brewtan
BREWTAN B
Brewtan B (formerly called Tanal B) is a 100% natural, high molecular weight tannic acid extracted from renewable plant materials specifically for the brewing industry. Incorporating Brewtan B into your process will improve the shelf life and enhance the flavor and colloidal stability of your beer.
The gallotannins in Brewtan B react with wort proteins through adsorption and precipitation - the Brewtan B/protein complex is left in the spent grains when Brewtan B is added to the mash, or removed in the whirlpool when it is added to the boiler.
It is highly effective at coagulating and flocculating proline and –thiol –containing proteins, but does not interact with foam-positive proteins. This in turn inhibits downstream lipid and protein oxidation, improving flavor stability and shelf life.
Dosage rate:
In the mash: 8 grams per barrel of mash liquor (8 g/1.17 hL). In the boiler: 5 grams per barrel of wort (5 g/1.17 hL).
Usage:
Dissolve powder in warm water; add solution to mash, boil, or both.
In the mash:
Add solution to mash water prior to dough-in. In the boiler: Add solution 0-5 minutes prior to end of boil.
Stability:
1 year, stored in airtight container in cool environment
Packaging:
available in 1 lb (0.45 kg), 3 lb (1.36 kg), 10 lb (4.53 kg), 25 lb (11.33 kg), and 50 lb (22.67 kg) units
