LD Carlson 9822 Whirlfloc Tablets, 10 count Review (2026)

What Whirlfloc tablets are

Whirlfloc tablets are a kettle fining made from a blend of Irish moss and purified carrageenan, sold by LD Carlson as a more concentrated, quick dissolving alternative to loose Irish moss. Their job is to encourage proteins and beta glucans in the wort to clump together into denser trub during the boil, so more of that haze-forming material settles out and gets left behind in the kettle rather than carried into the fermenter. This listing is a 10 count pack, a small, fresh-use size rather than the larger bulk bag LD Carlson also sells for brewers who go through fining tablets quickly.

How and when to use them

The common guidance for this product is to add one tablet per 5 gallon batch during roughly the last 5 to 10 minutes of the boil, since the active ingredients can denature and lose effectiveness if boiled much longer than that window. Some sources describe the tablets as strong enough to treat 10 to 15 gallons of wort per tablet, with smaller batches using a half tablet instead, so brewers should check the guidance on their specific packaging and start with the more conservative dose if unsure. Either way, timing near the end of the boil, rather than adding it earlier, is the detail that matters most for getting a useful result.

What it actually does

Kettle fining works during the hot and cold break, the points where proteins in the wort denature and clump from heat and then from rapid cooling, and Whirlfloc's carrageenan content helps that clumping happen more thoroughly than it would on its own. The result is typically a denser, more compact trub left behind in the kettle after the boil, and less protein haze carried forward into the fermenter and, eventually, the finished beer. It is a boil-side clarity aid rather than a fermentation or packaging additive, so its effect is on the wort before fermentation starts, not on the beer afterward.

What it will not fix

Whirlfloc addresses protein and beta glucan haze from the boil, but it does nothing to remove yeast cells still in suspension after fermentation, which is a separate kind of haze that shows up regardless of whether kettle fining was used. Brewers chasing a genuinely bright, yeast-clear beer typically still need cold crashing, time, a fining agent added after fermentation such as gelatin, or filtration on top of using a kettle fining like this one. Whirlfloc is best understood as one part of a clarity routine rather than a single fix for all haze in a finished beer.

Pack size and who it suits

At 10 tablets, this pack matches roughly ten single-batch uses at the common one-tablet-per-5-gallon-batch rate, which suits a home brewer who brews somewhat regularly and wants a fresh, not-too-large supply on hand rather than a bulk bag that could sit around for years and possibly lose potency. Frequent brewers going through more than ten batches a year will run out and need to reorder, and might find better value in LD Carlson's larger pack sizes instead. This product fits any all-grain or extract brewer who wants clearer beer out of the kettle and does not mind the small extra step of dropping a tablet in near the end of the boil.

Frequently asked questions