Unfortunately not all ovens are created equal...which means, some of our clients are struggling to maintain mash temperatures.
In our house, Mark loves to cook so purchasing our gas range was a no-brainer and the added expense was par for the course. Little did we know at the time that it would be so important in our brewing process!
As it turns out, many people brewing 1-Gallon batches of beer aren't able to maintain temperature of their mash using their ovens like we do because some manufacturers designed their ovens with a low temperature of only 170 F - too high for mashing...but not all is lost. There is still a couple things you can do to maintain your mash temps and come out with the final beer of your dreams:
1) Use the stove-top to maintain your mash temp...
Place your Brew Bag filled with grain into the pre-heated strike water and affix BINDER CLIPS to the edges of your stock pot, holding the Brew Bag in place so that the base hovers just above the base of your pot. Stir your mash around and take the temperature. If the temperature of your mash is below the recommended mash temperature, turn on the burner to slowly bring it up.
NOTE: we have been assured that our Brew Bags will not scorch at the temperatures needed to bring your mash temperature within range, however the sugars in your wort CAN so keeping the sugars (that may be stuck to the bag) off a direct heat source is recommended.
Monitor your temperature CLOSELY to ensure you do not overshoot your range...remember, when the temperature gets too high, you start converting starches into non-fermentable sugars, meaning your beer will be sweeter and lower gravity than intended.
When you reach your projected temperature, add a tight fitting lid to your pot to help insulate the mash and hold the temperature longer and TURN OFF THE HEAT. Check it every 10 minutes or so to ensure you're maintaining temperature and continue to add heat as needed.
If you find your mash has gone too high, you can add cold water to help reduce the temp quickly but it's best to keep a close eye if at all possible and avoid this.
2) Using a beverage cooler to control mash temperature...
Just like the bigger brewers (5+ gallons), you can use a beverage cooler (2 or 3 Gallon like the picture) to maintain your mash temps as the insulated walls will keep things warmer longer with less need to babysit so intently. Efficiency of this method will likely be quite good for the small batch you're brewing however you will want to keep track so that you can adjust your strike temp and mash time to accommodate.
Simply, heat your water to the strike temperature according to your recipe (if you built your own recipe, the software used will help calculate the expected drop). Add grains to brew bag (or not if chosen) and mix the grains into the water, then take the temperature. You should be within the temperature range (1-2 degrees F) of the recommended mash temp. At this point add the lid, close tight and leave the mash for the time recommended in the recipe (typically 60 min), still stirring every 15 minutes though to ensure good heat distribution.
You can expect to see the overall temperature drop a couple degrees F over the hour and this is ok because most of the saccharification (starch to sugar conversion) occurs in the first 10 minutes for good base malts and 15-25 minutes for coloured malts.
So, outside of purchasing a new oven, these are just two ways you can manage your mash with confidence.
The best way to know if you have completed the conversion of starches to sugars during the mash is to do the IODINE test. Iodine is known to cause starches to turn black. So...adding a drop or two to a small sample of the wort (no grains in the sample if possible) should indicate a black/purple colour if starches are still present (meaning your mash has not completed the conversion) and just a slight tan or reddish colour or no colour at all if all the starches have been fully converted.
Feel free to contact us anytime with your brewing questions!