Top 7 Winter Brewing Tips

Even though it’s many people’s least favorite season, winter is a critical stage in the yearly cycles of most all living things. It’s common to wonder how long to brew Kombucha in winter, along with other ferments like JUN, water kefir or milk kefir.

Even in warmer climes, the changes in air pressure, humidity and of course, temperature during winter all shift the way insects, plants, animals, and yes even our homebrews behave.

The healthy yeast and bacteria, which prefer warmer temps for the best results anyway, slow down when the weather gets cooler. Unless some of these winter fermentation tips are implemented, brewing issues like mold, off flavors, and stuck fermentation are more common at cooler times of year.

Apply any or all of these tips to keep your Kombucha, JUN, Milk Kefir and Water Kefir happy and productive, even as everything else hibernates. Plus we’ve included a few of our favorite “warm you up” flavoring recipes for any ferment!

Why Does Winter Create Brewing Issues?

As experienced brewers already know, low pH (under 4.0) is the home ferment’s key protection from contamination. If the pH remains too high for too long at the beginning of the brewing process, mold in the air and other invaders such as Kahm yeast can colonize the brew. Because the good bacteria and yeast in our brews are less active this time of year, the pH may drop more slowly. During that extra window of time is when brewing problems often emerge.

Many of the techniques below work by lowering the pH more quickly. This may be accomplished by increasing the ratio of SCOBY and starter liquid to sweet tea or by maintaining the proper temperatures.

CLICK HERE to learn more about pH and Kombucha

Winter Brewing Tip #1 – Seek Higher Ground

Everyone has heard “heat rises, cold sinks.” Heat doesn’t actually rise but hot air molecules move faster and have less density than cold air. As cool air seeps in under the door and through cracks in the window, it displaces the warmer air sending it higher. To take advantage of this natural thermodynamic flow, shift your brewing location to a higher location.

Higher ground locations:

• Top of the refrigerator
• High cabinet
• Closet shelf
• Atop or near the dryer in the laundry room

CLICK HERE for more about selecting the right brewing location for all your ferments

CLICK HERE for more on How To Flavor Kombucha

Winter Brewing Tip #2 – Snuggle Your Bugs

Another way to help your brews eke out a bit more warmth is to wrap them in a towel or layers of fabric. This can also be a great tool for making your heating mat more energy efficient provided the layers aren’t too thick and still allow the heat to dissipate naturally. We invented our Kombucha Kamp Brewer Tee Sets with this very concept in mind; by covering your vessel and sliding a heater underneath, the warmth is trapped closer to the vessel, helping to achieve the ideal range. Yet the t-shirt material is thin enough to be safely in use 24 hours a day. Think of it as a winter coat for your bacteria buddies!

Snuggle Options:

• Terry cloth towel (AMZ)
• Brewer Tee or Jar Tee Set
• Tea Towel (AMZ)

Kombucha Mamma Sez – BONUS TIP : “If your brew is normally stored on a marble, granite or any counter top that may feel cool to the touch, simply placing a cutting board or towel underneath it will help to keep it warmer. When stored on a cool surface, heat transfer causes the heat to disperse until the counter top and the jar are both at the same temperature. Shifting to a material that isn’t as cold means that less heat will transfer out of the brewing vessel. #physicsforthewin“

Winter Brewing Tip #3 – Invest in a Heat Mat

While wrapping the vessel in towels can help insulate the brew, it won’t create new heat. If you love fermenting and want to keep your brews happy throughout the seasons, a heating mat can be a valuable investment. Find one that works with your location and brewing style. Some simply raise the temperature by a few degrees whereas others, like the Ferment Friend, have a built in thermostat for full control and flexibility when the weather shifts.

CLICK HERE for more about Keeping All Your Ferments Warm

One key tip to remember is to HEAT FROM THE SIDES. It can be tempting to place jars on top of a typical seedling or basic heat mat. However, that will cause the yeast (which like to rest at the bottom of the vessel after a few days of brewing) to continuously remain active and hungry. The bacteria are not as feisty as the yeast, so they lose the battle for food if the yeast aren’t given a break. This often leads to unbalanced brews and off flavors.

Heating from the sides nurtures the bacteria rich liquid towards the top of the vessel while allowing the bottom to remain cooler. This maintains the necessary balance in the symbiosis.

KKamp’s Heat Mat Options:

• Ferment Friend with Thermostat – Set it and Forget it!
• Year Round Heating System with Dimmer – Dial the power from 0-100%
• Essential Heat Strip – Move the heater closer or further away to regulate

*Some common heating suggestions KKamp does NOT recommend:

• Drape Christmas lights around the jar – while this is pretty, light is antibacterial so it is not recommended as a heat source. And this method only raises the temperature by a few degrees anyway – *note this does not work with LED (most lights today) as they do not produce any heat.
• Set in oven with light on – this recommendation is not as common, but it can be problematic. It is possible for the acidity of the brew to cause corrosion in the oven. Additionally, we have heard from many folks that accidentally turned on the oven before remembering the brew was inside. RIP SCOBY!!

Kombucha Mamma Sez – BONUS TIP: “To increase the fizziness of bottled brews, place them near a heating mat or warm appliance. If you lose the fizz from the fridge, this is a perfect way to get them bubbly again. But be careful, too much heat and flavoring combined can be explosive!”

CLICK HERE for Bottling and Flavoring Safety Tips

Winter Brewing Tip #4 – Use More SCOBY & Starter Liquid / Kefir Grains

Kombucha has its own built-in defense mechanism – starter liquid! When temperatures fall, increasing the amount of culture and starter liquid in your batch will help to acidify the sweet tea and drop the pH more quickly to prevent mold and other contamination.

For most batches of Kombucha or JUN, we recommend at least 1 cup per gallon, 2 if possible. During colder months, 2 -4 cups of starter liquid per gallon is a good minimum. You could also double the SCOBY, or do one or the other. Both the SCOBY and the liquid will provide strength to the brew.

For kefir, simply use more grains, up to double the normal amount. This will give all your brews the extra low pH boost they need to stay protected.

Winter Brewing Tip #5 – Lengthen Fermentation Time & Make More Batches

All living creatures feel the changing seasons and our bacteria & yeast buddies are no different. They slow down as the weather cools. Even with the correct heat applied, batches still tend to take a bit longer than in Summer.

Plan for a few extra days for each batch to mature to your normal preferred taste. This may mean adding an extra batch to your brewing rotation in the meantime to help ensure you will have enough Kombucha, JUN, Milk Kefir or Water Kefir for the family to enjoy!

Fermentation Time Adjustments:

• Lengthen your fermentation time by a few days
• Start another jar so that you will have enough on hand
• Set up a batch before leaving town – even if it’s a little sour upon return, adding some fresh sweet tea, sugar solution or milk will yield a tasty product in less time

Winter Brewing Tip #6 – Brew in Smaller Batches

If you have a luxury of space, to help speed your fermentation along, consider making several half batches. The surface area to depth ratio will be greater since the liquid won’t fill the vessel as much which helps to speed the fermentation along. The downside is that more jars means they will take up more space.

Winter Brewing Tip #7 – Try Continuous Brew

Continuous Brew is our favorite way to make Kombucha. It’s easy, safe and when we leave 50-75% already fermented Kombucha in our vessel, it cuts down the brewing time to just days rather than weeks! Plus, if you need to take a break, provided the vessel has enough liquid, it can act like a SCOBY Hotel which you can then revive at any moment and have delicious Kombucha in just a couple of days!

CLICK HERE for more about Continuous Brew vs Batch Brew
CLICK HERE for a Continuous Brew FAQ

Kombucha Mamma Sez – BONUS TIP: “If your CB isn’t yielding as much fizz as you’d like, stir before decanting to evenly mix the yeast throughout the Kombucha. Then, when you decant through the spigot, you will see brown yeast strands in each bottle. That will ensure a more even distribution of the yeast for fizz in the bottles AND remove some of the excess yeast from the brew so you can go longer between cleanings.”

Have any other Winter brewing tips we missed? Leave them in the comments!