Fermtech Fast Flow Large 27" (0.5-Inch) Auto Siphon, Clear Review (2026)

Who this siphon fits

This is the Fast Flow Large model from Fermtech, a company that has made auto siphons for home brewers and vintners since inventing the original fast-racking design in 1987. It uses a 1/2 inch diameter racking cane, which is larger than the 5/16 inch bore found on Fermtech's Regular sized siphons, and is built for carboys and larger fermenters rather than small one gallon jugs. It fits brewers racking five gallon or larger batches who want to move beer or wine from primary to secondary fermentation, or into a bottling bucket, as quickly as possible to limit the time the liquid spends exposed to air during transfer.

Size, materials and design in plain English

The siphon is made of plastic and measures 27 inches in overall length, long enough to reach the bottom of most tall carboys and fermenters. It is designed to work with 7/16 inch inner diameter vinyl tubing, which is wider than the tubing used with Fermtech's Regular siphons, and this larger bore is the main reason transfers move noticeably faster than with a standard-size auto siphon. Like other Fermtech auto siphons, it starts with a single pump stroke rather than requiring you to suck on a hose or tilt the vessel, and it has a removable tip that can be taken off to draw liquid from the very bottom of a vessel, or left on to sit slightly above the surface and avoid picking up sediment.

Living with the siphon day to day

In use, you insert the siphon into the carboy or fermenter, give the center tube one pump stroke to start the flow, and the larger 1/2 inch bore then moves liquid substantially faster than a regular sized siphon would, which matters most when racking a full five or six gallon batch where a slow transfer means more time for oxygen exposure. The removable tip lets you choose between drawing from the very bottom of the vessel or holding just above the sediment layer, depending on how much trub or lees has settled. After use, the siphon disassembles for cleaning, and because the bore is wider than a regular siphon, it also tends to be quicker and easier to rinse thoroughly.

Trade-offs and how it compares

Against the Ubrew USA Regular Auto-Siphon with 6.5 feet of 5/16 inch tubing, this Large model moves liquid faster thanks to its wider bore, but the Ubrew Regular kit bundles a generous length of tubing and a clamp at a size that fits more standard carboy necks without modification. Compared with the Fermtech Regular 5/16 Auto-Siphon, the trade-off is the same: this Large version is faster for full batch transfers but its wider diameter will not fit through narrower carboy necks without care, and it requires sourcing 7/16 inch tubing separately rather than the 5/16 inch tubing that ships with some Regular siphon kits. Brewers who exclusively use narrow-neck one gallon jugs are better served by the Regular size.

Verdict and who should pick something else

This siphon suits brewers regularly racking full five gallon or larger batches who want to minimize oxygen exposure during transfer and are willing to source matching 7/16 inch tubing separately if it is not included with their specific listing. Its speed advantage over a standard siphon is the main reason to choose it. Brewers working mostly with narrow-neck carboys or one gallon jugs should choose the Regular sized Fermtech siphon instead, since the Large bore may not fit through a narrow opening without careful angling. Anyone new to auto siphons who wants a complete kit with tubing and a clamp already included may also prefer a bundled starter option over this component-only listing.

Frequently asked questions