Brewing Education: Filtering and Reclaiming Your Lees

Today's post is all about the different way that #homebrew methiers (mead makers) employ to attempt and filter out the lees from the mead at the bottom of your fermenting container in an attempt to reduce and ultimately eliminate the waste of mead when racking and bottling. There is quite a bit of debate between what is the best method and if it is even worth filtering due to the relatively minuscule amount of waste you leave behind to prevent the lees from transferring from racking containers to your bottles. The smaller a batch you make the more mead you are proportionally losing, however on average we find that we lose only 6-10oz on our first racking, and maybe 3 oz on our second; however after the second racking we don't typically have any noticeable lees at the bottom so we don't lose anything when bottling. Obviously the more you brew the more waste you will have but it is still insignificant to the volume of overall product in most cases - there are situations where if you attempt to rack to early or use pulpy juices you are going to see a lot more sediment at the bottom and that will cause higher waste rates - and in our opinion the only time you may want to consider filtration for reclamation is in a large-scale commercial operation where you have dozens of gallons of "waste".

Cold Crashing: This is a traditional process used by brewers to help settle particulates currently in suspension and has the added benefit of increasing the clarity of your brew. This process is quite simple, when your fermentation is finished, but before you rack your mead into a new container for the first time you bring the temperature of the mead down to near-freezing temperatures (34-40F) for at least three days and up to six days. This process has a few benefits such as halting yeast fermentation (cold temps make the yeast dormant - not dead - and halts fermentation), it decreases the time it takes for particles to settle out of suspension, and it helps quickly improve clarity of whatever you are brewing. This method has no effect on color, flavor, or alcohol content which means its a process to consider before using previously mentioned fining agents.

Note: Cold Crashing does not kill yeast, but only makes them go dormant, so if you cold crash your mead and then bring it back up to room temp and add sugar to it you will start another fermentation. If this happens when bottling you can turn your mead bottles into bombs - called bottle bombs - which could cause pretty serious injury. To kill yeast you need to pasteurize the mead (K-meta and K-sorbate don't actually kill yeast, but causes them to not produce alcohol and prevents them from reproducing).

Top Off: This method is probably the least complicated "filtration" method. The essential process is after you have siphoned out most of your mead and you are left with the "waste" mead and lees at the bottom of your container you swirl up the lees and mead to mix it and then transfer the liquid into smaller container (such as mason jars) and let it settle again. The smaller container volume means more mead gets pushed to the top and lets you reclaim more mead, and then you can use that mead to top off bottles/glasses, or just for a quick drink. This is also often paired with cold crashing the mason jars to help the lees floculate (particulate adherence) making it easier to pour out the mead without lees or to siphon the remaining mead out.

Filters: There are many types of different filtration products available for purchase that can be used at varying degrees of success, from coffee filters to home brewer specific filtration systems. As we just stated the success of these filters vary and typically filters like this are single use, which means you are adding more cost for your brewing hobby. Things like coffee filters have a micron filtration size larger than yeast cells and therefore won't filter out most of the lees, I only included it because it is often suggested on message forums. Yeast typically measure at 3-4 micrometers, which means anything with a filter size higher than 2 microns is not going to work. This takes us to the mead maker specific filtration products which actually do work, they just cost $50-$70 and the pads need to be replaced after each use which can be $5-$20 for each filtration pad, and this is all to reclaim a few ounces of mead. Unless you are making batches of 500 gallons or more at a time these kinds of products are just not cost effective.

Siphoning: If you are not wanting to use any of these methods there is a simple way of keeping the lees out of your bottles, and that is siphoning. Specifically careful siphoning. If you rack your brew at least twice and are careful in your siphoning you shouldn't end up with any noticeable sediment/lees in the bottom of your bottles. You will have a little bit of waste since you have to leave a small portion of the mead on top of the lees to prevent siphoning it into your racking containers and then your bottles. For this to be successful you do need to be aware of where your mead is at in the brewing process. If you rack and/or bottle to early you will have sediment build up on the bottom of your containers since the mead will be clearing when left alone in a container, so you have to be sure that your mead has finished, or is near finished with clearing so that you don't end up with sediment in your bottles and glasses. This just comes with experience and the more you brew the easier it will be for you to know when the right time to siphon is, which is different with each and every mead you make. Many message boards and forums will tell you that you have to do step x for 1 week and step y for two weeks, but that is really just a guideline and you will need to pay attention to your brew to see when the best time for you to proceed is.

That is all for today's post, but we will be back in a few days with another one for your reading pleasure. We are also looking forward to updating you all on both the Strawberry-Peach mead and the Blackberry-Rose mead within the next week or two, but until then

Stay safe and remember to love one another!

~ The Forge Meadery