Sparge methods

Clint · Jun 11, 2024

I did gain around 10% immediately.

Druncan · Jun 14, 2024

Sadfield said:
@Druncan Some form of Venturi Syphon and premixed treatment?

https://amzn.eu/d/cCiFGWM

Awesome m8! Great idea, thank you.

hoppyscotty · Jun 17, 2024

MmmBeer said:
I'm a non-squeezer.

The idea of sparging is to dissolve as much of the remaining sugars, without drawing tannins into your wort. Tannin is present in the grain husks and if you sparge at too high a temperature (roughly over 80°C) or continue to sparge after the sugar levels have dropped too low, you risk harsh tannins ending up in you finished beer.

It is recommended to stop sparging when the SG of the sparge flow drops to 1.008, as there is very little sugar left and that risk of tannins becomes significant. If you are worried that you havent collected enough volume in your kettle, it is safer to add more water or any remaining sparge liquor directly into the kettle.

Tannin extraction is a funcion of ph and temperature. So you'll be fine so long as the PH isn't around 6 and the temp isn't higher than 75 degrees C.

In fact the ideal ph for mashing is around 6 as far as the amalayse conversion process is concerned, but we pull it down to prevent the extraction of tannins during the mash.

Its more of an issue with my Brewzilla...I normally give the top plate a push to get the desired pre boil volume. I guess if I was more patient I'd just leave it for another 30 mins or so. On my larger 3 vessel system by the time the sparge is finished the grains are bone dry so I think the much higher weight of the grains performs a self-squeeze action.

The key to a decent fly sparge is speed...I know alot of people seem to be time critical with their brewing and looking for all manner of methods to reduce the brewery time, but the sparge on my 3 vessel system takes a good hour and the sparge water is trickled in as slowly as I can - but as it takes so much longer to come to the boil with my 3 vessel system I'm paralleling those processes so actually the total elapsed additional time of doing the long sparge is minimal. The idea here is that you have time for the sparge water to soak into the grains and flush out the remaining sugars within the grain husks. On my Brewzilla unless it's a thick grist I struggle to perform a controlled sparge as the sparge water just trickles straight through so not a particularly efficiency tor effective process on all in one systems full stop.

As has been said before though...no need to do a sparge, it's more for volume and efficiency than anything. With my 3 vessel system I'm getting a 90 litre pre-boil volume from a 70 or so litre mash (grain plus water). Would need a much larger mash tun with alot more volume to achieve the same pre-boil volume without a sparge.

crescent city Mike · Jun 18, 2024

I knew I had a little problem with astringency in some beers but it wasn’t noticeable in others. Color didn’t seem to be a factor with this occasional flaw as these beers were all over the map as far as style. The problem would come up from time to time and I had no idea when it would happen. I seemed to be at the mercy of some mystical force.

I checked the books to learn how to keep those pesky tannins out of my beer. Some texts said to stop collecting wort during the lauter at a SG of 1.008. Others said 1.010 or 1.012. That’s really a fairly widespread. What are the measurement parameters for this? Are these cut-off gravities based on OG? Are they based on color? Is this just a matter of hocus pocus and “feel”, or is it based on some scientific principle? I put this problem on my “things to figure out” list.

For a few batches, I started checking the SG toward the end of the lauter and stopped collecting at the suggested gravity. I still wondered why the tannins don’t leach out during the entire lauter. I found my answer in reading more technical publications. They seemed to lay it out in a way my puny brain could understand although I would have expected this explanation from basic brewing texts. As the sugars are being rinsed from the mash, so are the buffers which keep the pH down in the 5.1 to 5.5 range. As the sparge water, almost always with a higher pH, rinses these buffers out, the pH of the grain bed starts to rise. Once the grain bed rises to about pH 5.9, the tannins start to leach out of the hulls. The pH of the mash will continue to rise and eventually would match the pH of your sparge water, if you were to lauter that long. Raising the temp of the grain bed by using sparge water over 172 degrees just exacerbates the problem.

I read that many professional brewers acidify their sparge water to alleviate this condition. Sulfuric, lactic, and phosphoric acids were mentioned. I really didn’t have a clue as to which kind or even how much to use but this mystery seemed to be unravelling. I found John Palmer’s RA worksheet on the web and downloaded it. One part of this worksheet is a calculator for acidifying the sparge water. I used lactic acid in the amount set by the calculator on my next batch of beer. Toward the end of the collection, I checked gravity as well as pH which stayed low so I collected until I had enough for the boil. Neither the collected wort nor the finished beer had any perceivable astringency. I tried it again on subsequent batches and still found no astringency. The gravity of the final runnings seems to be of lesser concern if that wort doesn’t climb above pH 5.8.

The mystical force of “hocus pocus” has now been replaced by honest-to-goodness science. It has provided me with a technique which seems to have corrected the problem and is keeping astringency at bay in my brewing.