This week I cover mead making fermentation and finishing. Last week in part 1, I provided an overview of mead making and the first steps of making the must, pitching your yeast and adding nutrients. This week I will cover the remaining steps.
As I covered last week the key components of modern mead making are:
- A No-Boil Method – where the ingredients are simply mixed together with properly hydrated dry yeast.
- Staggered Mead Nutrients – Nitrogen rich nutrients are added over the first week of fermentation. Typically four additions are made at 24, 48, 72 hours and the last at about a week.
- Degassing During Fermentation – Unlike beer, the mead is degassed with a wine whip twice a day during fermentation until you reach roughly the 2/3 sugar break (2/3 of the way through fermentation).
- pH Management – While not a concern for low gravity and most pure honey meads, many acidic fruit meads (called Melomels) require monitoring of the pH which can drop significantly during fermentation.
- Stabilization and Finishing – Since honey can sometimes continue to ferment as conditions change, most mead makers stabilize their mead.
I covered the first two steps in part 1, so today we will discuss the last three steps.
Degassing During Fermentation
Mead, unlike beer, benefits from degassing during fermentation. Honey, being largely composed of sugar, can ferment very rapidly in the first stages of fermentation and build up a significant amount of CO2 in the form of carbonic acid. This carbonic acid can slow fermentation. Also mead is not damaged by the addition of some oxygen in the early stages of fermentation.
Most mead makers use a wine whip and electric drill to degas their mead about twice a day. For those not familiar a wine whip is a long shaft with some plastic arms on it that is used by wine makers to degas wine at the very end of fermentation. Some mead makers also use paint stirrers.
Degassing the mead involves simply driving the wine whip or paint stirrer with a drill for 30 seconds or so until a large portion of the CO2 gas is freed. This generates a lot of foam, so the vast majority of mead makers use large oversize plastic buckets during primary fermentation. For example I use a 9 gallon (34 l) plastic bucket to make about 5 gallons (19 l) of mead. The extra volume is needed to contain the foam.
If you are working with fresh fruit or puree in the mead its usually best to put it in a grain bag for easy removal and lift the bag while degassing so it is out of the way when whipping the must. Also its a good idea to turn any fruit over once or twice a day as it can develop mold if its left floating on top of the must for too long.
Continue degassing the mead twice a day until you hit roughly the 2/3 sugar break which is when 2/3 of the sugar has been fermented.
Managing Must pH Levels
For meads made completely with honey, the pH level is rarely a concern, but I like to make big fruit meads using acidic fruits. Highly acidic fruits can drive the pH levels down as fermentation progresses, so I monitor the pH and make adjustments if needed. The pH will drop as fermentation progresses.
The lower limit for me is a pH of 3.0, though I usually will make adjustments as the mead begins to drop into the 3.2-3.4 range. I use a calibrated pH meter to monitor the pH level of the must daily during active fermentation.
When the pH drops too low I will add some potassium bicarbonate to raise the pH levels back to the 3.4 level. For a 5 gallon (19 l) batch I will usually add a teaspoon of potassium bicarbonate powder and then wait a few hours until my next degassing session to check it again. If it is very early in fermentation and the pH is dropping quickly I might use more but usually a teaspoon or two will get me back to the acceptable range.
Fermentation, Aging and Stabilization
Using staggered mead nutrients and degassing, the primary fermentation can typically be completed in a few weeks, even for high gravity meads. Smaller session meads can sometimes be done in just a few days. I monitor the progress using a hydrometer added to the fermenter. I have found refractometers to be unreliable at the very high starting gravities used in my large meads, and have turned instead to just leaving a hydrometer in the fermenter for easy reference.
If working with fruit, I recommend keeping the fruit in a grain bag and removing it when the fruit starts to blanche (turn white) or roughly after the first week to 10 days.
When the primary fermentation has completed and the gravity has stabilized, transfer your mead to a secondary to aid in clarification and let it settle for a week or so. At this point you can add finings if desired. I’ve had some success using Super-Kleer, a two part fining used in wine making.
For high gravity meads, I allow a minimum of 60 days of aging from start of fermentation before I will keg the mead. Lower gravity meads can complete sooner, and you can taste them periodically to check their progress. Initially they will taste like rocket fuel but that will fade as they age.
Before bottling or kegging you should stabilize your mead using potassium sulfite. This is a wine additive that is a preservative and also insurance against further fermentation. You must also add sorbates if you want to backsweeten your mead, though I rarely backsweeten mine and instead target a final gravity that leaves some residual sweetness. I have a detailed article on sulfites here. I prefer my meads still, so I keg them at very low pressure, but you can carbonate using a pressurized keg. Still meads can be bottled, but you really can’t carbonate and bottle a stabilized mead.