Low Pre-boil Gravity

I could use a little advice with sparging… Ever since I got my new kettle, I’m been trying to sparge “properly”, as in my initial mash will have a water to grist ratio of 2:1, and then you sparge after your first runnings. But it seems like I’m not getting enough off my first runnings (~3 gallons), therefore my 2nd runnings just end up diluting it like crazy and I get low pre-boil gravities.

Should I just up my initial water amount so I get more wort at the higher gravity, and sparge less? When I did initially started all-grain, I just did it all in one go (because I had a small pot), so I just ended up with less beer, but at a good gravity, so I was fine with that. But now that I’ve got the bigger pot, I’m looking to make proper batches, but I just can’t seem to get this sparge down pat…!

Any advice would be awesome-o…

First thoughts would be that you’re looking at the wrong factor. #1 reason for low mash efficiency is the quality of your crush. To maximize efficiency, crush the grain as fine as you can without risking a stuck sparge.

But it could be something else as well. It sounds like you are batch sparging, is that right? Empty the mash, then add more water and empty it again? Or are you fly sparging? If the later, issues of geometry for your mash tun could be the problem.

If this is a new mash tun for you, as well as a new kettle, it may simply be that you have to dial your recipes in to account for the actual efficiency you can expect to get. More info should allow someone here to give you the exact advice to address your problem.

Post your grain bill and a little more about your process. Batch sparge, fly, BIAB? How far off your preboil SG are you?

Well I’m buying pre-crushed grain, which I’ve never had a problem with before, so not much I can do about that until I get a crusher. As for the mash tun, it’s just a igloo cooler which I’ve used quite a bit before.

But yes, I am batch sparging. How much should you let the grain bed settle (if at all) before adding sparge water? But I think you’re right in that I probably just need to dial in my recipe.

If you are batch sparging, the grain bed is fully settled (all the liquid is drained out) before you add your sparge water.

If the grain is pre-crushed, it is possible that you will see variation in the crush from order to order. Not every supplier is careful to make sure their mill stays at the same gap setting.

[quote=“arctic_brewer”]Well I’m buying pre-crushed grain, which I’ve never had a problem with before, so not much I can do about that until I get a crusher. As for the mash tun, it’s just a igloo cooler which I’ve used quite a bit before.

But yes, I am batch sparging. How much should you let the grain bed settle (if at all) before adding sparge water? But I think you’re right in that I probably just need to dial in my recipe.[/quote]

For proper batch sparging technique, see www.dennybrew.com. Feel free to ask me questions, too,

Thanks for the replies! Just one more question regarding batch vs. fly sparging. I know for fly sparging, you’re supposed to keep your grains saturated to keep the grain bed from compacting and releasing tannins, but for batch sparging you should drain your 1st runnings until you’re completely empty? Then add your sparge water for the 2nd runnings? Would that not release the same tannins?

Just curious as this would have contributed to my low gravity; I haven’t been draining my wort all the way, as I didn’t want to compact the grain bed.

Tannins are only an issue with temperature too high (180F+) and pH too high (~5.8+). Go ahead and drain all your first runnings, and then add your sparge water if you’re batch sparging.

Acidify sparge liquor to minimize but some tannin extraction is inevitable and a part of all grain brewing.

[quote=“arctic_brewer”]Thanks for the replies! Just one more question regarding batch vs. fly sparging. I know for fly sparging, you’re supposed to keep your grains saturated to keep the grain bed from compacting and releasing tannins, but for batch sparging you should drain your 1st runnings until you’re completely empty? Then add your sparge water for the 2nd runnings? Would that not release the same tannins?

Just curious as this would have contributed to my low gravity; I haven’t been draining my wort all the way, as I didn’t want to compact the grain bed.[/quote]
The physics at work for batch sparging and fly sparging are different. You don’t need to worry about tannin extraction with batch sparging because the pH will never go up enough to cause that. With fly sparging, it could at the very end when almost all the sugar has been extracted but there is still a lot of liquid flowing through the grain bed. Compacting wouldn’t be an issue either, as you simply stir up the grain when you add your sparge water. The down side being that you need to recirculate again before you drain the sparge.

But yes, drain the grain bed as much as you can before adding your sparge water (add it all at once) to increase efficiency when batch sparging.

Sorry rebuilt. I debunked this. I have the data to back it up. The logic behind it makes sense, but it is just not true.

Well if we want to get specific, it extends to both all-grain and extract. You’re picking up condensed tannins from not just the grain, but also from hop material in the boil. You can also get hydrolysable tannins from wood or fruit additions. But I should have said, you can minimize your condensed tannin extraction by controlling your sparge water pH and keeping the temperature below 180 or so. Of course you’ll still get some. :cheers:

Touche’ Sir! Pork, you employing anything to reduce this? Curious if a 90m boil would help.

Honestly, about 90% of the beers I make these days are sours or wild beers, and I’ve been playing around with ways to enhance and increase tannin content within what is appropriate for the style! This last weekend I sparged at 180F and boiled for 2.5 hours with aged hops, and had about a cup of flaked wheat tossed right in the boil. But I’m also going to be letting this one sit for over a year. So I don’t think I’d be of any help in reducing them, I think we’re going in two different directions. I’m very interested in hearing your results, though!

It depends on your water. My batch sparge pH behaves as rebuilt noted. Your data may only apply to your situation.

Yep, we’re going in different directions. An interesting thing I picked up is that some brewers actually add tannic acid to the mash and/or boil to reduce proteins as well as winemakers add tannins to certain wines. Easy enough to add…
http://www.northernbrewer.com/shop/winemaking/wine-ingredients/wine-tannin
It was also interesting to find out the main reason “oaking” mellows things is due to the tannins in the wood.

It depends on your water. My batch sparge pH behaves as rebuilt noted. Your data may only apply to your situation.[/quote]

Agreed and happy it works for you but that means batch sparging pH depends on water just like fly sparging…

It depends on your water. My batch sparge pH behaves as rebuilt noted. Your data may only apply to your situation.[/quote]
I did start acidifying my sparge water when I started to use Bru’n water, but the amount it calls for (with my very soft water) is so little that I’m pretty sure it makes no practical difference.

Lucky you! My water is 90ppm alkalinity which is half decent but my sparge still creeps up. The acid addition also helps setup overall pH and helps flavor too.

Yes, very lucky. 28ppm alkalinity. I’ve actually been able to make light lagers with straight tap water, but that does require a long acid rest to bring pH down.