TAPCRAFT Cooler Mash Tun Conversion Kit with Stainless False Bottom, Ball Valve (5 Gallon) Review (2026)

What it is

This is a parts kit for converting a standard round beverage cooler, the kind sold for coolers like Igloo or Rubbermaid water coolers, into a mash tun suitable for all grain brewing on a 5 gallon scale. The kit centers on a stainless steel false bottom that sits near the base of the cooler to let wort drain through while holding back the grain bed above it, paired with a full port 1 divided by 2 inch ball valve and a bulkhead fitting to let liquid flow out through the cooler wall. Silicone gaskets are included to seal the bulkhead against leaks where it passes through the cooler. TAPCRAFT sells this same design across a few sizes, with this listing scaled for a 5 gallon cooler conversion.

Who it fits

This kit is aimed at brewers moving from extract or partial mash brewing into full all grain batches, where a proper mash tun with a false bottom and drain valve becomes necessary to separate the sweet wort from the spent grain. It is a good fit for anyone on a budget who either already owns a round beverage cooler that can be repurposed, or is willing to buy one separately, rather than spending more on a purpose built mash tun vessel. Brewers who want a single box solution with the cooler already included should look elsewhere, since this is explicitly a conversion kit for parts only. It is sized for 5 gallon batches, so brewers regularly doing larger batch sizes would want the larger version of this same kit.

Strengths

A stainless false bottom is generally considered more durable and easier to keep clean than a braided hose style manifold, since it has no small gaps that trap grain particles and is simple to rinse off after a brew day. The full port ball valve is a meaningful detail, since a full port design does not restrict flow the way a reduced port valve can, helping wort drain at a reasonable pace during the lauter and sparge steps. Repurposing a cooler this way is also one of the more affordable routes into all grain brewing compared with buying a dedicated stainless mash tun vessel outright, while still giving the insulation benefit of a cooler body to help hold mash temperature steady during the rest.

Trade-offs

The cooler itself is not included in this kit, so buyers need either an existing round beverage cooler of a compatible size or need to budget for buying one separately, and not every cooler shape works well, since the false bottom and bulkhead are designed around a round rather than rectangular cooler. Installation involves drilling into the cooler wall to fit the bulkhead and carefully seating the silicone gaskets to avoid leaks, which is a reasonable DIY project but does take some care and basic tools the first time through. Because the mash tun relies on the cooler's own insulation, very long mash rests in a cold garage or basement can still see some temperature drift compared with an actively heated system.

Bottom line

For a homebrewer ready to step up into all grain brewing without spending on a dedicated stainless mash tun, this TAPCRAFT kit is a practical and reasonably priced way to get a working false bottom, valve, and gasket setup. The value depends on already having, or being willing to buy, a compatible round cooler, since the kit itself is parts only and does not include the vessel. With careful installation and a bit of patience drilling and sealing the bulkhead, it should hold up over many brew days and give a reliable lauter process for 5 gallon all grain batches.

Frequently asked questions