95 reviews
  • FLEX+
  • FLEX+
  • FLEX+



Introducing the new Spike Flex+! The Flex+ was designed to be the most versatile, upgradable and longest lasting small batch fermenter on the market. With currently over 20 accessories (and counting) you'll never run out of run toys to bling your Flex out with. The Flex+ is the big brother to the standard Flex. Out of the box it features an upgraded tri-clamp racking arm, tri-clamp butterfly valve and upgraded high pressure lid and clamp that can handle up to 15psi. The higher pressure rating allows for carbonating your beer in the same tank you fermenter in. Carbonate your beer in 24hrs opposed to 7 days!

You can view all the Flex+ accessories HERE.

All hardware shown HERE is included!

Flex Features:
-304 stainless steel; 1.2mm (18ga)
-All sanitary welded ports (no-weldless fittings)
-Designed for 2.5 to 6gal batches
    -7gal total capacity
-15psi working pressure
    -Use for pressure transfers
    -Use as a brite tank
-Etched volume markings
-Fully polished finish

-15" wide by 21¨ tall (to top of 4" TC)
-See additional dimensions here

Lid Features:
-Stainless band clamp for attaching the lid
    -Completely removable lid for easy cleaning
-4" TC modular top port
    -Allows for hop additions, temp control coil, top sight glass, etc

-(3) 1.5" TC ports which allow for: 

Blow Off Port – Dedicated port for an airlock or blow off tube
Hop Port – Dedicated port for adding hops
PRV Port – Dedicated port for your pressure relief valve (PRV)

Body Features:
-1.5" TC racking port with rotatable racking arm
-1.5" TC secondary port for thermometer, sample valve, etc

Flex Buyer's Guide

New to brewing? Haven't bought a Spike fermenter but feeling overwhelmed with the options? Well, we put together a Buyer's Guide just for you!

3 Port Lid Advantages

Racking Arm Included

  • Racking Arm
  • The Flex+ includes a tri-clamp rotatable racking arm as a standard item. This allows you to rotate the racking arm as you drain your Flex+. You’ll start draining in the upwards position and rotate until the beer stops running clear. The Flex+ comes with a racking arm that has an indicator so you can easily see what orientation the racking arm is at from the outside.


4" Lid Port

      • Lid port
      • The Flex+ features a 4” tri-clamp welded onto the lid. Why? Modularity. This allows you to attach our drop in temp control coil, clear cap and allows for easy hop additions. Our temp control coil extends deep into the Flex so both full batches (5-6gal) and half batches (2.5-3gal) can be efficiently cooled. The 4” port also allows for unmatched simplicity when adding hops during your fermentation. Gone are the days of removing the entire lid which allows oxygen in and also opens the door for an infection.


TC100 Full Temp Control Package

  • Temp control is arguably the most important aspect of brewing. Proper temperature control can eliminate off flavors and manipulate flavor profiles that different yeasts produce at different temps. Up until this point precise fermentation temp control was only available on larger more expensive fermenters – not anymore. Our full temp control package includes the temp coil, insulated tubing, quick connect tube fittings, cooling pump, insulated jacket and dual temp controller. We also have a heater available for us cold weather brewers. All that’s needed for cooling is a cold water source! Many people use a cooler with ice, fridge with a glycol reservoir or even a glycol chiller!


Primary, Secondary, Carbonate and Pressure Transfer

      • Pressure Transfers
      • We feel the Flex is the most versatile fermentation vessel on the market for the price point. The Flex+ can accomplish everything tanks 2-3 times its cost can do. You’ll easily be able to primary, secondary, carbonate (brite) and pressure transfer with one vessel!


Customer Reviews
4.9 Based on 95 Reviews
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Filter Reviews:
Scott C.
United States

Flex plus

First batch I made a smash lager it worked great. I am looking to buy some other accessories for it. I almost didn't purchase it because of its size and if you made a big brother to it. say 30 liter or 9 - 10 gallons i would buy two of them. ( I am used to filling a 5 gallon and a 3 gallon corny keg when I brew.) Meanwhile in the near future I will be purchasing two of your 20 gallon kettles after seeing the quality of this flex plus. Thanks Scott C. Hot springs ar.

Brian L.
United States United States

Flex plus

The fermentor does not hold pressure i have tried a bumch of times and it leaks. This not worth 400 dollars when my 200 dollar plastic one holds pressure like a champ. So make sure you post this review and stop curbing the reviews to make it look better. I will report to bettter business if I do not see it. People need all the reviews good or bad not the ones you all feel should be posted.



We reached out to this customer and talked to him over the phone to assist with troubleshooting the issue. We gave a few suggestions on how to resolve this. We followed up with the customer 2 weeks later asking for an update on if the issue has persisted to see if we can assist further. As of 9/3/21 we have not heard back. We are happy to help if this is not resolved.

Michael M.
United States United States

Great starter stainless fermenter.

This was my first stainless fermenter and it is great. Has the conical style bottom that yeast and hops will collect at so they do not get mixed in with packaging into either keg or bottles. Easy to clean with a CIP. Has numerous different attachments that can be used to customize your fermenter.

Martin S.
United States United States


My previous experience with fermenters was limited to one or the other of the various plastic fermenters available. My interest in the Flex+ was to integrate tightly with the Solo System, take advantage of home brewing process advances over the last few years, and provide the most efficient fermentation management in a very limited amount of space. I also wanted a company renowned for quality products and outstanding customer support. Flex+ hit the target on all aspects. Superbly engineered and exquisitely manufactured (I used to oversee submarine construction - Spike workmanship is excellent). Customer inquiries are responded to in less than 1 business day with genuine concern for my satisfaction. And the Flex+ has features that will allow me to expand my expertise in fermentation, The ONLY thing I miss is the ability to visually observe the fermentation in process, but there is a hand porthole for the top that helps with that.

maarten r.
United States United States

not being used for beer

HI all, WE are successfully using your setup to leak test epoxy potted flanges. Very happy with the results, not happy of course that the fermenter will never come into contact with any beer at all. One small negative is that we bought the casters. It's pretty clear they are unusable without the triangular plate you also sell. I did not realize how necessary the plate is. I recommend you don't sell the casters or the plate separately, but sell them as a kit only. It would have saved me the trouble of figuring out that without the plate the whole setup on casters is too unstable to be practical. No big deal overall, we are happy with our leak testing setup for our factory.