Milk

admin

Hi Guys - there was a piece in the Herald last weekend commenting about the effect of seasonality on milk texturing.

It seemed like the jury was out on whether seasonality made a difference - one person interviewed said it could make a huge difference, while another well-known barista said: 'a quality coffee maker can always coax a frothy top from their milk'

Does anyone know the scientific background to the milk seasonality question?

Admin

FreshCoffee2

I am going to stick my neck out...yet again. Yes seasonality does affect the amount of froth that can be coaxed from milk and, it all has to do with the PROTEIN level in the milk at various time due to seasonal changes, as well as the type of cows, the type of pasture and therefore the location, the amount of "stress" i.e. how long has the cow been lactating and is it due for a  break, is it a time of drought or "plenty", etc etc etc. Could one of our learned Forum lurkers please expand on the PROTEIN thing as this ultimately is what governs frothability (you try sneaking in an unlikely word like "texturability" and keep your credibility intact). FC.

john

From ADC, Australian Dairy Corporation 07122000 Frothing Characteristics of Milk The frothing in cappuccino is produced by injecting steam into cold milk until it almost boils. The volume of the frothed up milk should be more than twice the original volume of milk and the froth should be fairly stable for at least ten minutes. At various times during the year steam frothing problems appear. This is mainly in the autumn months. A limited amount of research has been conducted to identify the causes of the phenomenom, but still it remains the basis of much debate. The most common explanation and one that is generally regarded as being the most likely is that the problem is caused by lipolysis. This is the name given to the hydrolytic breakdown of the milk fat by natural milk enzymes. The reason that milk in the autumn months seems more susceptible to lipolysis is that it is at the time of the year that cows are getting toward the end of the lactation cycle, and the fatty acid profiles produced in the milk resulting from the cows being in this stage of its yearly cycle are more prone to lipolytic action. This time of year also coincides with a reduction in natural pastures available for feeding. Changes in diet due to supplementary feeding is another reason proffered for the changing susceptibility of milk fats to lipolysis. IMPROVING THE FROTHING CAPABILITIES OF MILK. Most times of the year milk froths well and is difficult to improve on this. There are certain processing variables that can be optimised however to maximise frothing especially in the difficult months. In short these are: -to minimise the incorporation of air in the milk -avoid excessive pumping and -minimise the storage time from the time of milking Heat treatment such as pasteurisation as well as homogenisation can also improve frothing ability. The higher the homogenisation pressure the more marked benefit. NOTE: the above has been reproduced from ADC notes dated 7th December 2000 I have some udder info but I will have to seek it out. JD

Reschsmooth

Nice pun there John - guess you gotta milk it for all it's worth, eh? ;D Fresh, if one of the Forum participants HAPPENS to be lurking, but that is ancillary to their normal participation, does that still make them a lurker? (Can you tell it's Friday afternoon?  ??? ) P

john

P One could say it is a cow of a topic. 8) Do we leave it there. ??? JD

Reschsmooth

JD That's no bull you're speaking! We could go on until the cows come home, right? NOW, we can leave it there (not wishing to have the last word, of course) P

Reschsmooth

Seriously, I understood that at times of the year, the cows are fed hay instead of eating normal grass, which affects the proteins, etc. Forum member Mimmo responded with this in another thread (hey, I don't know how to do the quoting thing in these forums): "The seasonality, is not really due to the feed, but more to do with the weather. The best milk comes in spring and autumn, when the cows are least stressed.   In the summer they tend to underproduce, and in winter they overproduce which lessens the quality. That is why the milk price given to the farmers (before deregualtion) used to vary considerably between winter and summer. Lower price in winter (greater supply) and higher price in summer (lower supply). Most dairy cattle in WA, are fed dry hay, silage, and green grass all year round, that is in the irrigation areas in the southwest though. So they are pretty much eating the same feed all year. Milk quantity also varies by the amount of walking a cow does each day. Cows that are on relatively flat ground will produce more milk than thier cousins in the hilly regions. Some friends of mine have two farms, one on the flats and the other in the hills, only about 20ks apart. With a heard of 300 cattle, the 150 cows on the flat produce around 6000L per day, and the 150 cows in the hills produce around 5700L per day. May not seem like much, but in a week thats a lot of milk." Sounds reasonable enough. I just know that, of late, the ability to texture milk at home has dropped off significantly of late - either that, or the milk is different. P

FreshCoffee2

Thankyou John, now here's a bit more. Let me know when you TYRE KICKERS (thankyou Patrick) have had enough, as the following could very easily put you to sleep! Straight from our local milk company laboratory: "..The Problem of Poor Steam Frothing (that's PSF to you) of Milk in eXpresso coffee machines: The cause is well established and is due to increased action of lipase, an enzyme that is present in all raw milk. This enzyme acts on the fat (triglycerides) in the milk, producing monoglycerides and diglycerides (NB both harmless) which have surface active properties and are FOAM SUPPRESSANTS. This phenomenon is known as "lipolysis" and it ceases when the milk is pasteurised. Unfortunately by the time this happens the damage to the milk has already been done. Stimulation of lipase action can be caused by excessive agitation and foaming or temperature changes of the raw milk in milking machines, pipelines, pumps or storage tanks. However with the equipment design and technological understanding of today, this really is providing only a minor contribution to the problem. The major cause is the production of "naturally active" milk by individual cows and it has been reported that from 3 to 35% of cows in a herd have been shown to produce milk with high lipase activity. The cause of the "natural activity" is in turn related to THE STAGE IN LACTATION AND FEED AND NUTRITION OF THE COW. Eg., many cows will produce "naturally active" milk in the last month of lactation and similarly most cows will produce "naturally active" milk if their level of nutrition is sufficiently low. It can therefore be expected that during summer / autumn when many cows are in LATE LACTATION, lipase problems will be most prevalent. These problems will be accentuated if the season has been poor and there is little green feed available. Lipolysis is a world wide problem and one that is difficult to solve particularly under drought conditions, and the cost of isolating all "naturally active milk" would be prohibitive...." There you go, top that! FC.

Reschsmooth

Oh, and Fresh, what's happened? Your last two posts have been under about 300 words!  ;D

FreshCoffee2

Actually Patrick, well below my usual average as the last post is 99% milk lab report, only leaving me with less than about 50 words! I like that. FC.

Unknown

are patrick and fresh coffee lovers?

FreshCoffee2

If Patrick was a Patricia, mebee, but alas, I dont think so. I like the comraderie between regular participants in forums like this...you don't? FC.

over_extracted

very well said john there are problems sometimes with milk,a few years ago i spoke to this milk farmer and he said it was becouse of the food that the cow gets,guess we all have our own little secrets as to what to do during this times.see ya OE ;D

admin

Hi Eddie - I take great pride in the friendly, relaxed banter that seems to have grown along with this Forum. If you're lonely, there's always Jan (see 'Not happy Jan' thread) - sounds like she could do with some cheering up. ciao -A

Reschsmooth

Eduardo, just don't let my girlfriend find out, eh? She would kill me. I have to presume you are under the age of about 14 or highly skilled in the use of sarcasm (however inappropriate).  ;D P

john

Admin Crema match making? Email a date?? Eddie and Jan Jan and Eddie Jan says "Not happy Eddie" Eddie says "Not happy Jan" Jeddi? Did we establish if Jan is m or f? What about Eddie? not sure if it sounds right. I do not think I am making sense. Time for an espresso. What was the Topic? JD

admin

Actually JD, I'm guessing Jan was a guy - although it would have been nice if he'd had balls enough to post his complaint under his real name... Anyway, back to the topic - there are quite a few specialty milks being marketed out there for coffee making - National Foods has one (Cafe I think) and I understand Dairy Farmers has come out with one named after our illustrious publication (Crema) - does anyone know if they perform differently or better or than normal milks? -A

Reschsmooth

A, I have tried Crema on my little Saeco, and have not been convinced that it is much better than other 'regular' full-fat milk for texturing. On one of the two occasions I have used it, I was unable to achieve a result which was much better than the sloppy, large bubble froth I often get from skim, and other times it was marginally better than the tighter froth (unfortunately not micro-foam) I normally get from full-fat milk. Interested on others' experieces on real machines!  :o P

pab

I've tried the Cafe Crema milk and the Pura Gold compared to standard average milk. The Crema milk wasn't much different to the standard. I found the gold milk to be, obviously, fuller. I still found that all three milks did vary from month to month on its ability to froth. In saying that I'm more than happy to continue researching this with my new Giotto!!!

Steamed

Not used Crema but have used Paul's Froth Top. Although it seemed to be a little more consistent than "full fat" milk it wasn't perfect and still had batches which was difficult to froth properly. I hadn't noticed seasonality as far as when this occurred (other than when it was really busy and you really didn't need the milk to make your job more difficult). The last time I experienced this would have been two to three months ago. Usually you can let the jug sit for a couple of seconds after steaming and then give bang it on the counter top followed by a couple of swirls. Have recently changed to Riverina milk, "full fat". So far consistency is very good.  

Bean_Counter

If you look at the chemical percentages on the labels there's not much diff between standard full cream and the Crema, you'd have to ask the guys at the milk lab what the've done but the results are there if your consistant in your frothing. The Crema is for caps/lattes and more to the point more idiot proof for dummies.It gives a smoother, tighter froth with a lot less "stretching" but if your doing flats stick to the normal milk.

admin

POSTED ON BEHALF: i, for one believe that 'crema' is milk for 'baristas' who can't steam milk. it has a sweet thick palate that covers alot of the more subtle flavours of the espresso. sure, it counters the problem of the couple of months a year when dairy farmers milk is thin and crap- but that's the problem in itself. change brands of milk, i use riverina fresh and it is perfectly consistent year-round. i've left the point here, i know [comments by J.Phil]

j-pil

any milk that claims to be 'specially for baristas' is full of crap. any barista worth their salt has already changed to riverina fresh, which, is cheaper than dairy farmers, (i hear pauls is good too). Organic is also the go, however more expensive. the problem with milk being crap at certain times of the year- i understand- has as much to do with the health and well-being of the cows as it does the production methods employed by the milk company and farmer. i haven't really done any research, but 'riverina fresh' seem to have a more wholesome approach to the whole farming thing. i guess this results in happier cows or something like that. but what i do know is that after two years using it, i haven't had a single problem, it is perfectly consistent. That aside, 'crema' is just not right (notice it isn't even called milk- but 'modified milk'). it has a sweeter, thicker palate that masks the more subtle characteristics of espresso. sure it boasts the endorsement of Paul Basset (WBC champion 2003), but go around a few of the best cafes in town and just try to spot it. those who know, say no. incidentally i spotted Paul's signature, even his face, on one or two other products while at aroma. 'dairy farmers' have alot of money. I'll do a bit of research reguarding milk companies and post something more conclusive in the not too distant future.              

Gonzo

re: "...That aside, 'crema'...modified milk...has a sweeter, thicker palate that masks the more subtle characteristics of espresso...." All milk masks the subtle characteristics of espresso. You only use a 30ml espresso, and around 120 mls or more of milk, per cap/latt/flattie, and that's only if you are using correct sized containers, otherwise, there can be even more milk in there. In my honest opinion, to say that one milk masks the espresso more than another, is superfluous. The best milk coffee is made with full cream / fat milk. The thicker the palate, the better, and as long as it has not been destroyed by incorreket FROTHING technique and excess temperature, this is what adds that beautiful, "sweet", neutral, well balanced, thick body to the beverage. If you are after espresso, you ask for one, otherwise you are asking for milk coffee, period. What's espresso, about a capp? On the other hand I agree with you...an experienced or well trained operator does not need froth enhanced milk products. This is like 2 boiler machines...they are for people who would like to think they are a barister but cant quite hack the pace and need help. G. PS. notice use of the word common english language word "FROTHING"...if you have changed over to TEXTURING because you cant hack using a plain english word, move overseas to somewhere where they speak in metaphors or something. Is it froth on my capp, or "texture"?? What's next, "massaging" the milk? Get a life for Chr...sake. Now yas can all go and choke on ya biscottis and leave me to my Sat evening scotch and cigar.

j-pil

i'm well aware of the constitution of coffee and the effect  milk has on it's flavour gonzo, that's why we're here. in australia and most other countries in the new world the majority of espresso coffee consumed is made with milk. upon dairy farmers attempt to woo me back to the flock with crema, i conducted a blind tasting, with just glasses of milk and also with coffee made with the milks. the difference was quite noticeable. i endeavour to make the best coffee i can. with, or without milk. i only use the best ingredients i can get my hands on. in conclusion, a 'flattie' as you call it made with crema is inferior in taste to a 'flattie' made with unmodified milk. all the best in your quest to change the world into espresso  drinkers gonzo, meanwhile i'll make them the best damn 'flatties' i can.

Gonzo

Re: "....upon dairy farmers attempt to woo me back to the flock with crema, i conducted a blind tasting, with just glasses of milk and also with coffee made with the milks. the difference was quite noticeable.

j-pil

now, gonzo. you wrote... "My beef with earlier post is simply that I believe no one can discern any subtle differences or effect ON THE ESPRESSO base, due to or attributed to the nuances of the type of milk, in a milk coffee...it simply comes down to the total experience, the balance, the body exhibited, the total flavour, and whether the espresso base is simply strong enough to come through all that milk fat. That's all. It's simple." I clearly stated that, exactly that which you claim is impossible, i have done, or, you missed the point. one CAN discern the differences between milks and the effect these have on the flavour of the espresso base inasmuch as 'crema' is not normal milk and the differences that exist there can be isolated with-or-without espresso. in fact some blends are specifically designed around the ability of the flavour profile of particular beans to come through the flavour of milk. don't take this as any kind of attack- i'm just trying to make my point clear, and this is: that 'crema' is noticeably inferior to normal milk and should be avoided by those who wish to make the best MILK coffee . And that the problem with milk being difficult to TEXTURE (we'll discuss this word if you wish) at certain times of the year can be solved by simply changing to a cheaper product, namely 'riverina fresh'(year-round consistency). p.s. this is not a plug for any particular brand of milk, i'm just speaking from experience. i also love a good argument

Unknown

Hey there everyone, I wanting to know if anyone can help me out there with the texturing of soy milk? I'm doing a good job although I would like to make the foam more dense. I put my soy milk in my frothing jug and put it in the freezer while I'm expressing my coffe I bleed off the water from the steam nozzle before texturing, I get pretty good foam, I want better. I guess it's the search we are all on for the perfect coffee in our own home. Thanks in advance

Bean_Counter

Try different brands,some are better than others. Simple as that I'm afraid.

j-pil

i've found that if you steam it a little earlier- say, before you do the espresso- and then let it sit for at least 30 seconds on top of the coffee machine (so it dosen't lose temp), it seems to calm down a bit and dosen't do that ugly curdle thing with the crema in the top of the coffee. give it a good working (shake and swirl the jug) just before pouring. as for more froth, like the last guy said, change brands. if you're using 'Sungold'- don't, ever read the ingredients? it only has something like 4% soy protein isolate (it's not even called soy milk). try vitasoy or bonsoy, your soy drinkers will thank you for it.

Reschsmooth

From a home espresso perspective (such that a 2L bottle of milk lasts 3-4 days), I have noticed that is significantly easier to froth the milk into a nice silky texture when it is 'fresher' (ie, just after I have bought it) compared to when you are near the end of the bottle. Any thoughts or comments? Patrick