I think i already know the answer to this but does a high sparge temp have an adverse effect on attenuation? I’ve been heating my sparge water on the high side lately and my efficiency has gone way up but my attenuation has been crappy. Pretty sure i need to lower the temp but just wanted to confirm with some other folks before i make changes. Thanks
I can’t imagine how high sparge temps could effect attenuation. You’re not going over 170* right? If you are I don’t think it will effect attenuation, but it will extract tannins from the grain.
High mash temps obviously will. Temperature issues in fermentation will (too low or fluctuating too much or WAY too high).
Are you sure the yeast you are starting with and how you are treating it is the same as before? How many batches is this trend?
I’ve been sparging really high and have noticed a small amount of bitterness from tannins. Typically I mash at 151-153. Usually do a started with liquid yeast and pitch after it’s been going for a day or so. Use oxy to aerate the wort. Ferment in the basement which is a fairly constant temp. Depending on the brew the OG tends to be in the upper to mid 150’s. I would say it’s been an issue for the last 6 batches. Sort of stumped new issue can’t quite figure it out. Brew house Efficiency is usually spot on at 70-73%,
I’ve not noticed a problem sparging hot and getting good attenuation. On the tannin front, if you can acidify your sparge water somewhat you will avoid extracting tannins even with very hot water, my sparge water is just under a boil when I turn off the heat so probably 180+ when it hits the grain.
Like Mort, my sparge water runs about 190. I’ve never seen the grain bed go over 170, so no tannin problems. Because I control my mash pH, I’m not certain I’d have to worry about tannins even if I used hotter water. In short, sparge temp should have nothing to do with attenuation UNLESS you have a significant amount of conversion left to happen after your mash time. That’s very unlikely, and if it’s what’s happening, you have a different problem to deal with. But I expect that should show up as low efficiency.
My efficiency is usually pretty decent, 70-73%, I have noticed the last few time’s ive kegged i have more wort then usual, but given the efficiency and my og readings i’ve not been all that concerned.
In that case, I don’t see how sparge temp could be having effect on your attenuation. By the time you sparge, conversion is done.
Crap, Looks like i need to rethink this then.
you could eliminate/confirm yeast health and actual wort fermentatbility by doing a fast ferment test (or forced ferment test maybe)
take a portion of your wort, or even ‘finished’ beer and hit it with lots of yeast, like lots and lots. and swirl it like you would a starter and keep it really warm like upper 70’s 80’s basically make an environment that the yeast will want to be really really active in. when that has all settled down you should be at a real maximum apparent attenuation given the wort and yeast you are using.
If it is lower than you have been seeing consider looking at your yeast health factors. If it is more or less the same as you are seeing in the full batch you know that there is something funky going on in your mash process and your yeast is likely fine.
Thanks Ill give that a try.
Out of curiosity are you washing/re-using your yeast? It might be that the harvested yeast is mutating over time and the overall attenuation is becoming an issue, just a thought…
I’ve had this issue with a couple strains that I frequently use and found that after 5-7 harvests the yeast begin to behave a little differently like less attenuation or lower flocculation, things like that, subtle but noticeable
I’ve had the same issue with both new and “used” yeast. Been brewing for a while with the only addition to my mash being 5.2. I know a lot of people say stay away from it but I’ve never noticed an adverse effect on things. My tap water is pretty decent for brewing. I’m going to try lowering my boil volume, my pre boil gravity seems good buy my og at times seems a little low. It’s the only thing i can think of that may be an issue.
Increased efficiency makes sense since you’re basically doing a mash out with the warmer temperatures. If your attenuation is going down but efficiency is going up it sounds like a yeast health issue. With increased efficiency your attenuation would go down if your yeast are fermenting the same amount of sugar as before but unless you are producing a lot of unfermentable sugars in your mash out you should also see attenuation remain fairly constant unless you are brewing really big beers or using poor attenuating strains.
I would check your mash conversion before sparging to see whether you are getting a lot of conversion in your mash out. Work on getting conversion complete before sparging. If there is a problem there, look at mash temperature, ph and consider ditching 5.2.
If mash conversion is ok look at your pitching. Are you pitching enough yeast for the OG? Aerating/oxygenating enough? Adding nutrient? Keeping fermentation temperatures warm enough for fermentation to reach full attenuation?
White labs did a study of “chronic underaeration” and ^^^^ this was their findings, with noticeable differences by the 5th generation.
If your thermometer were off by 5 degrees, this could account for the attenuation.
The more wort you collect the higher your efficiency will be and without boiling off the “excess” your og will be lower.
I would suspect that you are still getting conversion, which is mostly less fermentable due to the higher temps. Absolutely nothing wrong with 190ish sparge water.
You have not said: how hot the water is, how you sparge, how long you sparge, or what the difference in attenuation is. And I’m hoping you are using similar grain bills. This info would be key in really figuring out the issue.
Sparge water tends to be just south of boiling 190-200 occasionally i will pull water while it’s boiling, i have a chest cooler mash tun and keep at least two inches of water above the grain bed, my sparge lasts about 45 minutes to an hour at least. I trust my thermometer. I rarely use yeast that is beyond it’s third use.
That’s what it needs to be to get the bed to mashout temperature (>80°C) by the midpoint of the sparge.
Tannin extraction is a function of pH, which has almost no dependence on temperature. The proper thing to do would be check your mash and sparge pH. (And stop using the Buffer 5.2, which could be where the off-flavor is coming from.)
Still trying to think this out, going to experiment with some wort from my next beer, Just to clarify morticaixavier how much yeast do you mean my a ton? two packets of dry yeast is what i was thinking.
probably 1 packet in a quart would be more than enough
Kai Troester has some great info on this (http://braukaiser.com/wiki/index.php?title=Fast_Ferment_Test). He advocates using regular bread yeast if you don’t want to use up any of your beer yeast (1/2 tsp to 8 oz wort). I usually add my test wort to the dregs left in my flask after I pitch my starter, but I’ve also used bread yeast because I always have it around (I keep a jar of loose yeast in the fridge for baking). If you don’t have loose bread yeast, there is 2-1/4 tsp yeast in a typical bread yeast packet.