# Moisture increase after baling - what’s normal?



## WindrowFarmConway (Aug 4, 2018)

Hi all! Small scale commercial mixed grass hay farmer here in Massachusetts. All small square bales.

I'm often the first one to attempt dry hay in town. It's often beautiful quality, but acts strange in storage compared to the rest of first cut. This year I got a moisture meter (Delmhorst), and when baling both the in-baler probes and hand probe agreed I was at 8-10% moisture. (Around here below 15% is what I've always heard as ideal.)

Just to be safe I stacked this hay single layer, cut side up in the barn. Lo and behold, both 24 and now 48 hours later, there is a small amount of perceivable dampness to the touch, and the moisture meter now reads anywhere from 15% to 22% (usually 16-18). This is my first time with a moisture meter, so I have nothing to compare to.

In short, is it normal for recently baled hay to have a spike of moisture content in the barn? Zero signs of heat, but don't want this beautiful feed to mold/dust on me. Plan to keep it single layer cut side up as long as I can and keep checking, but can't figure out if I'm missing something. Also don't want to panic and sell it as discounted use-asap "feeder bales" - but would prefer that to a batch of dusty mulch in a month or two.

Any thoughts welcome! (Just remember - northeast, mixed grass, small squares)

Thanks!


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## Tx Jim (Jun 30, 2014)

Yes it's normal for baled hay moisture % to rise in the 1st few days after baling. I've had rd bales that tested 15% moisture test in the low-mid 20% range in next few days. Old timers called it "going through a sweat".


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## Gearclash (Nov 25, 2010)

Agree with what Tx Jim says. Make sure the bales have air circulation around them so any moisture that wants to leave the bale can get away. If there is not heating I would not be concerned. Slight temp rise wouldn't worry me either. Since you are new to moisture meters, be aware that hand held meters will show heating after repeated probing simply from the friction of the hay acting on the tip of the probe. If my brother is monitoring internal bale temp he stabs the tester in a bale and leaves it there. Checks it on a daily basis usually.


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## HayMike (Mar 22, 2011)

Here in Ohio, same problem. I'm never happy with dry down of early hay. It's still standing for now this year.


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## slowzuki (Mar 8, 2011)

Water in the core of plant cells takes longer to get released. It keeps coming out after you bale. If you did a microwave test from window you would see you moisture is higher than a probe tells you.


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## 8350HiTech (Jul 26, 2013)

HayMike said:


> Here in Ohio, same problem. I'm never happy with dry down of early hay. It's still standing for now this year.


I've mowed some in Pennsylvania but if I saw a reading of 8-10 this time of year I would dismiss it as too low without even a second thought.


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## WindrowFarmConway (Aug 4, 2018)

Thanks for all the responses! I'm crossing my fingers for the "sweating" possibility - in anyone's experience, any sense how many days that cycle tends to take?

Microwave test is a good idea. I've never tried that either, but it makes sense that the meter was likely missing some of the deeper stem moisture content. The leaves and finer grass stalks were *definitely* at 8-10% (we had an unseasonable warm spell of 85 degree super sunny super breezy weather). But I bet those pesky orchardgrass stems are the culprit.

With the heat/friction issue with repeated probe use - is that simply that heat on the probe creates a higher reading? (My probe doesn't read temp, just moisture - but I did see in the manual that it'll tend to read 1% higher for every 20 degrees that the material is over 80 degrees. I have a hard time believing the friction would make that much extra probe heat, right? Or might it?

Strikes me as so odd that come June first, even the still green first cut is no problem. I've grown up on hay and always trust my "by feel" approach *except* for this super early stuff, which seems to just throw all of my instincts out the window. Something stark changes in the span of a week or two, re: the stem's ability to dry.

Maybe in future years just waiting is the answer. I tend to keep picking up acreage and worry about the last fields being overripe, so my rationale is that I'd rather a light yield of beautiful stuff on the first field than a load of brown crap on the last field - but that only works if I can dry the early stuff.

Anyway, thanks for the help! And happy to hear any other thoughts if they're out there.


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## Tx Jim (Jun 30, 2014)

Another thing I've observed while utilizing a moisture tester is that direction of insertion of tester probe into bale & tightness of bale affects % reading. Tighter the bale will cause reading to rise a small amount & inserting probe in sides of sq bales vs areas of bales held by twine such as bale ends/tops affects tester moisture %.


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## WindrowFarmConway (Aug 4, 2018)

Tx Jim said:


> Another thing I've observed while utilizing a moisture tester is that direction of insertion of tester probe into bale & tightness of bale affects % reading. Tighter the bale will cause reading to rise a small amount & inserting probe in sides of sq bales vs areas of bales held by twine such as bale ends/tops affects tester moisture %.


That makes sense. I go from bale ends or diagonally from the sides to make sure probe is going as cross-flake as possible into denser sections. (This is what the manual said to do). I did notice that just inserting it from the side between flakes gave a lower reading, which I discounted


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## Hayman1 (Jul 6, 2013)

kind of interesting, we have been haying like crazy for about 10 days with very low humidity, and clear skies with occasional breeze. Hay is drying in 3 days with multiple teddings and intermittent use of haygard. I have not seen rehydration in a windrow overnight until last night. Weird, the ground is bone dry, even the buttercups have stopped flowering for the most part. Grass planted in very early March is 2 " tall and stopped in its tracks. Pretty sure the 90 degree temps today will dry the hay for 2-3 pm baling.


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## Hay diddle diddle (Nov 17, 2017)

As someone else said. Big difference between moisture from dew and stem moisture. If its cured dew moisture will burn off quickly as you are baling. Stem moisture wont change during baling. Will give you a false sense of security that it's right to bale. I ALWAYS make sure my hay is bone dry in the row the late afternoon before I make it. Only way to be sure the stem moisture is fine.


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## sprout (Jan 1, 2018)

Trust the tester when you bale it. I have went back and checked a couple days later and was worried. If it's dry when I bale it, I never worry about it after, it will just make me loose sleep over the sweat.


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## slowzuki (Mar 8, 2011)

I should have added, the twist test doesn’t lie like a meter. If you grab a little bundle of stems about 4” apart between your hands, offset it into a set of bike pedals shape and “pedal”. Anything much over 3 twists before it breaks you will see quite a bit of stem moisture release after baling and need acid or single layer stacking to let it dry in bale.


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## Manning Haymaker (7 mo ago)

Hi there. Here a year later in Ohio, in the same situation. Do you remember if your hay turned out or if it ended up molding?


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## calico190xt (9 mo ago)

I was hoping to hear about the result too. Maybe he is busy or not checking back. 

After seeing this post, i went and checked some recently baled hay and while it did go up since I baled it, the temps of all of it are ranging around 70 degrees. Moisture meter was showing 12-15 on most bales during baling but after about a week in the barn, it went up to 18-20 here and there. I probed 10 bales. I don't think it is going to be a problem. I had a 4th cutting last year that wouldn't dry and the bales were heavy and over 20% here and there and I fed them to sheep all winter, flake by flake. I never saw any mold. I think mold happens around 120 degrees so I am far from that. I am guessing if you watch your temps and see things go over 100 degrees then you should start to worry.


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## slowzuki (Mar 8, 2011)

The mould / bacteria growing is what causes the heating not the other way around. 



calico190xt said:


> I was hoping to hear about the result too. Maybe he is busy or not checking back.
> 
> After seeing this post, i went and checked some recently baled hay and while it did go up since I baled it, the temps of all of it are ranging around 70 degrees. Moisture meter was showing 12-15 on most bales during baling but after about a week in the barn, it went up to 18-20 here and there. I probed 10 bales. I don't think it is going to be a problem. I had a 4th cutting last year that wouldn't dry and the bales were heavy and over 20% here and there and I fed them to sheep all winter, flake by flake. I never saw any mold. I think mold happens around 120 degrees so I am far from that. I am guessing if you watch your temps and see things go over 100 degrees then you should start to worry.


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## ttazzman (Sep 29, 2019)

The more stem in your hay the more sweat you will have....so first cut will naturally have more....we have seen first cut bales at 15% or less rise to 20% in the barn with no issues...but we always watch things if we start with marginal moisture hay 18%ish we will let it sweat on the wagon for several days before barning it or stack it separately.....but moisture rise can be a bit disconcerting


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## calico190xt (9 mo ago)

Thanks for the correction on mold first. I am trying to keep as much on the wagons as I can to avoid moving twice so I am doing that by default. I am going to keep probing just to watch behavior of temps. I agree that 1st cut should be the worst of it. Is the sweat normally a two week process? That's what I always heard but it may require no stacking to have that happen.


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## slowzuki (Mar 8, 2011)

The overall "sweat" time and heating risk time is complicated but "here" without rain, set on trailers, they either heat and get mould where the bales touch each other or the floor, or dry adequately to be put in after a week.



calico190xt said:


> Thanks for the correction on mold first. I am trying to keep as much on the wagons as I can to avoid moving twice so I am doing that by default. I am going to keep probing just to watch behavior of temps. I agree that 1st cut should be the worst of it. Is the sweat normally a two week process? That's what I always heard but it may require no stacking to have that happen.


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## WindrowFarmConway (Aug 4, 2018)

Manning Haymaker said:


> Hi there. Here a year later in Ohio, in the same situation. Do you remember if your hay turned out or if it ended up molding?


Hi there! Just pure dumb luck that I saw another reply here, but thanks for checking!! 

So that hay from last year appeared to come out the other side okay. Still felt a little "juicy", but no mold. Had customers take it and have good luck (it even gave one goat bloat, it was so rich - yikes, all was okay). Only had one customer say her animals rejected it, but her animals reject all sorts of hay that I know is good - it wasn't moldy still, even in March of this past year, and smelled fine!


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## WindrowFarmConway (Aug 4, 2018)

sprout said:


> Trust the tester when you bale it. I have went back and checked a couple days later and was worried. If it's dry when I bale it, I never worry about it after, it will just make me loose sleep over the sweat.


That helps!! That's the threshold I'm trying to figure out. Plenty of stuff I know is good and don't bother re-testing in the barn, so never quite sure what the unquestionably good stuff does


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## WindrowFarmConway (Aug 4, 2018)

calico190xt said:


> I was hoping to hear about the result too. Maybe he is busy or not checking back.
> 
> After seeing this post, i went and checked some recently baled hay and while it did go up since I baled it, the temps of all of it are ranging around 70 degrees. Moisture meter was showing 12-15 on most bales during baling but after about a week in the barn, it went up to 18-20 here and there. I probed 10 bales. I don't think it is going to be a problem. I had a 4th cutting last year that wouldn't dry and the bales were heavy and over 20% here and there and I fed them to sheep all winter, flake by flake. I never saw any mold. I think mold happens around 120 degrees so I am far from that. I am guessing if you watch your temps and see things go over 100 degrees then you should start to worry.


That makes sense! And about the same range I'm seeing. Did a similar early batch this year (last week of May), gave it four full days to cure in the field. Excellent moisture at baling, slight creep in the barn up to 18% or so, and seems _perfect_. I'm hopeful!


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## WindrowFarmConway (Aug 4, 2018)

ttazzman said:


> The more stem in your hay the more sweat you will have....so first cut will naturally have more....we have seen first cut bales at 15% or less rise to 20% in the barn with no issues...but we always watch things if we start with marginal moisture hay 18%ish we will let it sweat on the wagon for several days before barning it or stack it separately.....but moisture rise can be a bit disconcerting


That's super helpful! This is the same tact I'm taking too, but really appreciate hearing that others agree. Thanks!


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## calico190xt (9 mo ago)

Thanks for seeing this post again and getting back on the results!


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## WindrowFarmConway (Aug 4, 2018)

calico190xt said:


> Thanks for seeing this post again and getting back on the results!


Absolutely! Sorry that I dropped off about it last year.

With this year's early batch, I also baled about 12 bales at the 3-day mark (rather than the 4-day mark) to compare. Those bales felt pretty good and had ~15% moisture at baling, but have spiked to 19-25% in storage (even though it's only 12 bales and they're sitting in one corner, single layer, cut-side up). No heat or anything, and no visible mold yet, but you can smell / feel the slight damp "funk" happening. I'm going to keep them all summer and see how they do (for science).

So, I'm extra glad I gave this year's early batch an extra day. My takeaway is that the super early first cut needs that.


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## swmnhay (Jun 13, 2008)

Probes measure moisture on what the probe is touching but if inside of stem is wetter the probe may say 15% but the inside maybe 25% and in reality it’s 20% hay that’s one reason it’s reads wetter after it is baled a day or 2.

IT can also happen in reverse if have bone dry hay and bale at night the monitor may say 30% but a day later may say 18% because the stems are dry inside.

Just another reason why moisture readings change after baled besides going threw the sweat


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## WindrowFarmConway (Aug 4, 2018)

swmnhay said:


> Probes measure moisture on what the probe is touching but if inside of stem is wetter the probe may say 15% but the inside maybe 25% and in reality it’s 20% hay that’s one reason it’s reads wetter after it is baled a day or 2.
> 
> IT can also happen in reverse if have bone dry hay and bale at night the monitor may say 30% but a day later may say 18% because the stems are dry inside.
> 
> Just another reason why moisture readings change after baled besides going threw the sweat


That makes a lot of sense! Thanks. I suppose it's ultimately not as mysterious as I first thought, and I think all came from doing it by feel for years, then getting a meter and relying on it _too_ much last year - and now having a nice middle-road approach where I go by feel, backed up with what the meter says (knowing it doesn't give a good read on stem moisture).

Appreciated!


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