Some like it hot, some like it cold

Sam has a very definitive taste when it comes to bottles. He will never take frozen milk that's been thawed in the fridge. Nor will he take frozen milk that's been rewarmed a second time. [update: since correcting the lipase issue and freezing immediately after expressing, Sam will take a bottle that's been rewarmed twice! So he doesn't have to finish his bottle in one shot anymore.] Now we know it's probably because of my excess lipase issue. He also likes his bottles really warm, even warmer than the temperature of milk when nursing, which is presumably 98.6 degrees or so. I wonder if that somehow masks the metallic/soapy taste caused by the lipase.

So I try to freeze my milk in two categories: full bottles like 4-5 ounces, and toppers of 1-3 ounces. This way, if I even think Sam might not want a full bottle, I try to have him take a smaller bag's worth so we don't waste so much milk. He will not take the leftovers a second time, only on random occasions, but I can't rely on that.

I don't have his bottle-taking habits down to a science because I'm not the one who actually gives him bottles. He wouldn't take one from - the last time we tried was when he was 2 months old, so who knows. Maybe he would drink from a bottle if I administered it. But there's really no need for me to give him one if I could nurse him. Sam only gets bottles at the babysitter, so she's the expert!

Fresh frozen and the excess lipase saga

Oxymoron? A scary thing happened to me, I freaked out, I worked to combat it, and it miraculously righted itself with an easy solution: fresh frozen.

Last week Monday Sam refused his normal amount of milk at the babysitter. He usually has a 5 oz bottle at around 11ish and then a 4 oz bottle at around 2-3. That day he had a total of 5 oz. Tuesday he did that again. Same with Wednesday. Each of those days he came home with the remainder of the milk in the bottle. It looked yellowish. I smelled it. I almost barfed. But milk smells, I've heard, so I daringly tasted a drop and BLECHEROO! It really tasted soapy and metallic. No wonder Sam turned it down. He has better taste than that. 

Turns out my milk has excess lipase. There are SO many articles out there that discuss it so I won't go into too much detail. But basically, everyone's BM has lipase, which is an enzyme that breaks down the fat so the baby can digest it. Usually this breaking down of lipase does not happen right away (I think it takes place inside the baby's body), but in some people, they have so much of it that the milk fat becomes broken down much quicker. Some people 4 hours later, some a day later, and some only find their freezer stash of one month old milk is bad. So it's really a unique situation for everyone.

What does one do about that? Some babies are totally cool with the yucky taste and drink the milk anyway. It's perfectly safe. Remember, the milk is just broken down, not spoiled. If baby will not drink it, don't blame him because it truly is yucko. The solution? Heat the milk (aka "scald" it) to 180 degrees and then quickly cool it before storing - this deactivates the enzyme and keeps your milk tasting delicious. That's such a pain, though, if you have to scald at each pumping session because your milk won't last the day in the fridge.

I decided to see how long my milk can "last" before it gets that ewwy taste/smell. I pumped a bit and put it in the fridge. After 4 hours it was fine. After 8 hours it already had a faint metallic taste. 24 hours later it's a strong metallic/soapy taste, plus it smells bad when heated. It didn't smell in the fridge when cold. 

Now this brought back to mind the early days when I went back to work. Sam did not take the bottle willingly at all. He would drink just an ounce or two and then another ounce or two a few hours later. He ate just to tide him over until he got hungry again. Poor boy. He did nurse well once at home and made up for it so I wasn't too worried. He was gaining weight as well. After about 3-4 weeks he would take a complete bottle. Now I think I know why. I'll bet that milk was also lipasey. In addition, Sam doesn't eat warmed up milk that slowly thawed in the fridge. Only milk that went straight from freezer to hot water. 

Later on he either A) got used to the taste and realized this is the situation and you gotta adapt, or B) the lipase was only really bad in the early days, which is common because there is more fat then or something. 

Well, now it seems to be bad again. Also lately I would freeze my milk only once I prepared the bottles for the next day - which was nighttime. Many hours after I'd pumped. So it was in the fridge during most of the day, slowly ickifying itself until the next afternoon when Sam would unwillingly drink just a bit. In the past I'd freeze the milk at work already, right after pumping - I don't know why. I just did that. Turns out that was the key to my solution.

I sent Sam some milk for this Monday that was scalded. He drank it beautifully. It also did not turn yellow, according to the babysitter. And the residue remaining in the bottle by the time he came home did NOT stink. On Tuesday I sent him with fresh frozen milk - milk that was frozen immediately after pumping - and he also drank it all really nicely!

Top: milk unaffected by lipase
Bottom: milk affected by lipase

So for now we are sticking with fresh frozen so I am spared the time-consuming task of scalding it each day. Freezing, I will dutifully point out, does cause some of the milk's important properties to be lost (scalding can also do that, btw), however it is MUCH better to serve this than formula. It's really of no health concern unless the baby only drinks frozen milk - we are talking just two bottles a day here, so no biggie.

Just a reminder: Milk that was affected by lipase activity looks yellower when thawed (but whiter when frozen), looks really fatty when warmed up, you can often see small globules of fat, it smells really bad, and has the taste of metal or soap. It IS safe to eat. The best thing to do if your baby is refusing bottles is to not blame it on the bottle - just taste the milk and you'll know for sure! Also, if you store milk for a freezer stash, defrost a bag every two weeks or so and make sure it tastes/smells fine.

Notice the picture on the left: The milk on top looks like milk should look when frozen. Pale yellow color, of even consistency. The bottom bag contains milk in which lipase already did its thing. You can see separate fatty sections and the milk is overall whiter and thicker looking.