HOW CAN YOU KEEP THE CULTURES WARM ENOUGH?
There are a variety of ways to help keep cultures warm enough to culture well during cooler weather. No matter the method you choose, it is important to verify the temperature.
Always test the temperature by leaving a jar of water in the new culturing area, then measuring the temperature of the water over several hours. If the temperature stays in range for your particular culture for 6-24 hours, you’ve found a good culturing spot.
Here are some suggestions for keeping cultures warm enough when the temperature outside drops...
Many people have appliances in their homes such as DVRs that are always plugged in. Simply set the jar in a dish or on a plate, then place it on top of the appliance to culture.
Seedling or Reptile Mat
A seedling mat from a garden supply store, or a reptile mat from a pet supply store can raise the temperature 5-20ºF above ambient temperature. This is perfect for products that need to culture at a cozy room temperature. Note: Read the instructions to verify temperature. Some mats run too warm for room temperature cultures.
A heating pad set to low may work similarly to a seedling or reptile mat and raise the temperature just enough to keep your cultures happy and thriving. Be sure to check any instructions and test the temperature of the heating pad before using with your cultures. You'll want to make sure that the culturing temperature stays within the appropriate range for your culture(s).
It may be sufficient to simply set the culture in a high place in the kitchen, where the air is a little warmer than at counter height.
You may be able to maintain a “room temperature” environment by putting your culture inside a food cooler along with a jar of hot water. Check the cooler occasionally and replace the hot water if necessary, to maintain a temperature inside the cooler of at least 70°F.
The oven may maintain an ideal temperature with just the inside light on. Temperatures can range from 75°-110°F, depending on the oven and bulb wattage. Just be sure you remember your cultures are inside before you start prepping your next meal!
You can help a culture retain its own heat by wrapping it in a dishtowel. You may want to experiment with different amounts of layers to achieve that perfect culturing temperature.
Sometimes just setting the culture near an incandescent lamp can provide it with enough heat to culture well. Be careful though, putting it right under a lamp may be too warm of an environment.
Insulated Cooler and Water
Place yogurt jars in an insulated cooler, pouring 105ºF to 115ºF water inside about ¾ the way up the jars. Close the cooler lid tightly and cover it in a blanket or towel. Change out water if temperature drops below 105ºF.
A convenient fold-out box that delivers predictable and accurate low-temperature heat. Digital controls provide temperature settings from 70-120ºF (21 – 49C).
Yogotherm Yogurt Incubator
This insulated container maintains temperature without electricity. Ambient temperature can have an effect on the culturing process; in cold weather, wrap with a warmed towel for added insulation.