Welcome back, my fellow nerds! When we last spoke, we were discussing frost damage and the science behind it and the conditions that affect it. I feel like I owe you all a third and final entry on what happened this summer with the crop that survived. But before that, let's go back to a topic we introduced last year around this time of year - measuring apple maturity. If you recall from vol. I, it's common for these kinds of evaluations to start by qualitative analysis by people with color vision. I'm not so great at the color vision thing, so I'm training myself in the more quantitative methods. I referenced, in that entry, the penetrometer. In this entry, you'll see it put to use. Don't worry, it's safe to view at work!
Apple firmness, measured in pounds per square inch, is a common maturity analysis for apples destined to be processed into apple sauce, pie filling, juice, and cider. There's a minimum pressure (16 psi) fruit processors require to receive fruit as "premium" - below this measure, pressure can be limiting in terms of which products can be made with this fruit. While it's most useful for processing fruit, we're very familiar with what to expect for changes in firmness over time so it's also useful for fresh fruit analysis around here, especially when paired with spectrometer reading (see entry 1) and when you make multiple readings over time. I'm hoping to start checking for starch with iodine as also referenced in entry 1 but for now, let's see just how this instrument is used.
Once you've assembled your penetrometer, the next step is to pick some fruit! I usually start with the one that, visually, looks the "most ripe" or the one that picks the easiest - two qualitative visual cues. Then, I try to pick another fruit that "representative of the rest of the tree" or block, in some cases. This way, I can communicate to the harvest crew us how much of a spot-picking job this is going to be. Some varieties ripen more uniformly than others. The apple I'm testing in these shots is the new, syrupy sweet selection known as 'Blondie'.
Fruit in hand, we first use a knife (no farmer should be caught without one) to remove the fruit skin (above) - this is a measure of the firmness of the apple flesh. We use a hand held penetrometer - great for field tests. If you were conducting research using firmness as a metric, you'd need a bench model that insures even pressure, steady pressure, and a perfect perpendicular angle. No such needs in our case, but one thing in common with both is a defined depth of penetration to remove that variable. This close up shot shows the indented ring at which the reading is taken (right). Then, holding the apple still on a firm, sturdy surface with one hand, the plunger shown in that picture is pushed into the flesh of the apple until the plunger reaches penetrates the distance from the bottom to that line. When that line is achieved, you remove the penetrometer and take your reading. The penetrometer is designed kind of like a high/low thermometer - the needle freezes at the maximum pressure applied. So for the best reading, it's important to stop pushing after you hit that line - the apple flesh will get firmer the closer to the core you get. Below are pictures of the penetrometer in action - keep in mind, the methodology described above doesn't leave a hand free so I'm attempting to steady the apple and push the penetrometer with the same hand (huzzah). When you're trying this at home (ha!) without the camera, it's one hand on the fruit one hand applying even steady pressure at a perfect downward angle on the fruit.
Blondie at 15.5 brix (not pictured) and 18.5 psi? She's ready to go. Enjoy those apples, nerds and be sure to check back in for more nerdy detail.
In the past, you have (or maybe haven't) read me blogging about in depth growing practices, answering your questions from the interwebs, and creating content to address some of our most frequently asked questions at market. All these have been fun "blog series" to write if you want to call them such a thing but I hadn't come up with the next thing to write about until today when I was tasked with judging the maturity to harvest of about 6 different apple varieties. I took to Instagram to nerd out when I realized, hey! This might make for a fun read! And when you're as nerdy as I am with... well... everything, then you're pretty much of the opinion that there's a large population of folks eager to nerd out with you. So, in blatant denial of the truth - that being, of course, that you couldn't be any less interested, I introduce the new blog series, Nerdy Ag.
So! Apple trees exhibit two kinds of growth: vegetative and propagative. While that statement alone warrants another blog entry unto itself, we'll concern ourselves only of the propagative growth which is how we get fruit - that is to say vegetative growth makes limbs and leaves, propagative gives us fruit. We'll talk about buds and biennial trees later. A pollinated blossom forms a tiny fruitlet that undergoes rapid cell division. After "June drop" these apples start to grow by cell division and finally, begin to convert starches to sugars. There are many ways to tell if an apple is "mature" or ripe - some sensory, some scientific.
The first indicator is seed color. The apple (matured ovary, nerds) isn't making it's final maturing stages until the seeds have gone from a green color to a darker, browner color. If you cut open an apple and see green seeds, you need test anything else - you're looking at a "green" (immature, unripe) fruit.
A second test for apples that have mature seeds is a starch-iodine test. Again, apples that are cut and tested are immediately discarded, so let not your heart be troubled. To perform a starch iodine test, you'll need to cut the apple horizontally and use a garden spritzer to apple an iodine solution. When the Iodine reacts with the flesh of the apple, you can determine what percentage of starches have been converted to sugars. Because this starch conversion to sugars continue post harvest, it's important to consult charts like this to determine when to harvest (see also 8 index chart).
A third test, popular in the processing apple industry, is using a penetrometer. As the name implies, this tests the firmness of the apple by the resistance pressure made by the cells of the apples flesh! A reading of the pressure at the time of delivery of apples to a processor is an important metric in deciding what products can/should be made with them. Fancy penetrometers are for inside, lab use only and sit on a table to remove all other variables. Hand held penetrometers are more common, as they are easy to take to the field with you, though steps must be made to insure the accuracy of measurements. This final, fourth mention of the term "penetrometer" is merely to see if there's still anyone out there with a middle school sense of humor who hasn't giggled.
But the fun and easy one that I use the most is the refractometer (pictured). This measures the brix, the amount of sugar, in a suspended solution, of which apple juice (cider) is one. We'll talk sensory tests later, but as one who is somewhat sensory deficient, this is my method of choice. Testing is done by squeezing the juice of an apple onto the pen-like tip of this kaleidoscope measuring device. Once you flatten this solution into a thin, uniform film, you can point the refractometer at the light and see the reading as you look into the eyepiece. Let's get this gadget working!
Let's start with a low brix reading. Please consider the Braeburn apple pictured to the right, here. As you can tell from the photo - my iPhone camera lens through the eyepiece of the refractometer, this apple is measuring only 12 brix (bx). To taste this apple, you'd agree - underripe. And, true to form, this would be about 10-15 days earlier than we'd ever harvested Braeburn otherwise.
But! As you'll also see form the picture, it looks like a ready-to-eat apple! I'm colorblind, so I'm making myself learn fruit maturity the scientific way and this is a situation in which it's really helpful. However, I'm also blessed with a discerning palette and it wasn't hard for anyone to find this apple green, starchy, and unsweet to taste it. Let's move on - I only tested this one because I was driving by it on the way to other fruits!
These next two varieties had different brix but were both deemed to be ready for harvest. The first was a slam dunk. It's only the second harvest for these here at Three Springs but they're quickly becoming one of my favorites - Pink Lady cv. 'Maslin', an early ripening mutuation of Pink Lady cv. 'Cripps Pink'. As you can see in the photo, these chimed in at a brix over 15 which is really great! Most importantly, they tasted like they were ready.
As did the Cameo, pictured on the right. Long a favorite here around the farm for their flavor, crunch, and storability. This is an apple we typically sell straight through March, April, and May so at a few fewer brix, these will be harvested at a maturity that will 1) taste good now, right off the tree and 2) have some starches that can convert to sugar in a storage scenario such that the fruit continues to mature and sweeten in storage, rather than spoil.
The next apple I tested is one we get a lot of questions about in the fall: Stayman. Without going into the differences between Stayman, Winesap, and Stayman/Winesap (this is the first of these) - 'Snapp' Stayman for the real hort nerds out there was an apple that measured high in brix but I didn't think was quite ready. We were hoping to harvest these with the likes of Cameo and Pink Lady 'Maslin' from a logistics/efficiency/management perspective. However, while the instruments put Stayman on par with 'Maslin' Pink Lady - it still tasted starchy to me. I just think this one needs a little more time. From a logistics standpoint, the next chance we would have to harvest it would be the following week at the same time, but I think that'll be worth the wait based 100% on my own sensory evaluation.
The final case we'll look at is the same apple in two different areas of our same farm. We'll call this variety Mystery Apple (to torture you) and we'll call the first location X, and the second Y (he said quite nerdishly). Mystery Apple, location X is on a semi-dwarfing disease resistant rootstock - G.16. These are planted between an existing block of Honeycrisp on m.26 (also semi dwarf) and a windbreak beside a little brook. What this means is shading - significantly less sun than site Y. It is, however, lower elevation and a consistently warmer site than site Y and the rootstock more dwarfing. Trees on site X are also significantly younger than Y, less mature. While I have witnessed more dwarfing (read, more light inception) and young (smaller) trees produce higher quality fruit, these apples at site X, while a little inconclusive if you look at that shot, were, at best about a 14-15 bx.
Meanwhile, older more mature trees, on a more vigorous rootstock, at a higher elevation (colder) site (Y) produced mystery apples with a brix of 21! I'll keep an eye on these two blocks going forward but Mystery apple harvested last year at a brix of 24 and since this year was a little more mild, heat-wise, I'll call these ready to harvest at 21 for 2015. But this is just a cool, nerdy, scientific horticultural wonder to keep an eye on as these two blocks mature. Block Y will be less light inception per tree in full sun. Block X will be more light inception at a half-day's sun. Which will produce better quality (higher brix) Mystery apples. It's science - that's what makes these mysteries fun!
** EDIT 10/12/2015 **
This nerdy blog references penetrometers and starch-iodine tests! See video below from PA Apples for MORE nerdy content including videos of both nerdy instruments in action! Note, that bench penetrometer will be much more accurate than our hand-held penetrometer!
Apple harvest is just getting started in PA. Did you know that apples are carefully hand harvested? Here's a look at the harvest process. #PickPAapplesPosted by Pennsylvania Apples on Tuesday, August 12, 2014
It takes a lot of good people to make us successful. And certainly, Shane is a big part of our success at market! When you see Shane and Lauren at market, thank them for their hard work and see what he's "arted" from our produce this week! Also, check out his Instagram feed for updates on produce art , it was recently featured in American Fruit Grower magazine!
I try to answer every question I'm asked - from regular customers to random web wanderers. But if there is any query that is likely to stand out from the crowd, it's an intriguing question from a web lurker overseas. We received a comment matching this description (ref. "Ask" vol II) from Prasanjit this week, checking in from India:
4/30/2012 @ 3:23 am
We're located in the city of Mumbai, India. We have lawys loved growing our own veggies, and I decided to grow an apple seedling, from the seed of a Granny Smith apple. After it sprouted and began to leaf well, I tried the same with Gala and Red delicious apples too. Now I have 4-5 young saplings, 2 each of GS and Gala, and one of Red Delicious.
I have now begun to realise that I will likely not get a GS apple from a GS sapling. However, is it possible for me to graft between these saplings I've grown from seed, and obtain a GS/Gala/Red delicious apple? Do let me know. I would really love to be able to grow these on our farmland, and atleast receive one type of edible apple from these 5 saplings I'm growing.
Thank you, Prasanjit! It's actually a fairly difficult thing to rear an apple tree from a seed, so you're doing quite well for starters.
For the history buffs out there, grafting has been an agricultural practice for more than 4000 years by some accounts. Even today all fruit orchards depend on the skilled grafting hand of a nurseryman to provide the trees that feed people. The same is true for any number of nut trees, grape vines, and a whole slug of ornamental trees and plants.
To address your question, you can graft any variety on those those seedlings and produce apples of a variety you prefer. What you'll need is some scionwood (budwood) and a little education. Just to reemphasize for clarity, you'll need to have cuttings of a living, growing Red Delicious or Granny Smith tree to have the budwood to graft over the seedlings.
Without knowing the diameter of your seedling, it's hard to provide foolproof advice. Provided your seedling trees are at least 5/8 inches in diameter (that's about 16mm), you should have enough plant material to chip bud your seedlings. You'll want to leave the top of the tree grow and make leaves to feed the rest of the tree. Using the chip budding techniques in the videos below, you'll be able to attach several buds to each seedling and they should grow - provided your cuts were straight and sterile and your union (cambium to cambium for all my fellow botany nerds) is good.
What might be fun is to leave the top of the tree, the old variety, in long enough to try some fruit before you cut it out. Sure, it may be nothing like the Granny smith you hoped for, but it might be a good variety, you never know. Perhaps it will be a new discovery - the world's greatest apple! Just don't forget who suggested leaving that branch in when the budwood is distributed!
And if the apples aren't good, just cut that part out!
- Farmer Ben
Further "Ask A Grower" reading:
So I'm mixing my Alton Brown references with "The Tick", and no, I don't expect anyone to keep up with this nonsense. I'm just be preparing you the reader for my own level of acute, scientific detail I've come to love from Alton Brown as the blog moves along.
On to our question! This one is a very common question, most recently posed via our twitter account by New York-based food blogger NutmegNanny via our good friend Michelle at eatniks:
"@NutmegNanny Can you store apples in the fridge?"
Not only can you store apples in your refrigerator, it is my recommendation that you do! Unlike other edibles - onions, potatoes, eggplant, and tomatoes come to mind, that will endure internal cellular damage and flavor alteration when stored at refrigerator temps, apples thrive and endure in your chilly frigidaire (as do peaches, but that's another blog for another time).
While I endorse refrigeration as the preferred method of apple preservation, it does come with a caveat or two. As the aforementioned Alton Brown frequently reminds his audience, refrigerators are often victims of cross contamination and "flavor blending" and apples are no different. The best spot for your apples is in the crisper with other veggies and fruits such as greens or carrots, geographically separated from proteins, dairy etc. Apples are not spoiled by moist environments the way other fruit and veg might be so no extra effort is required to remove your fruits from moisture. Truthfully, a little moisture will help keep your apples fresh as dry atmospheric conditions in your fridge can cause moisture to be pulled from the fruit - you'll discover this in the form of wrinkled apple skin after prolonged fridge time. Cut apples are not to be reinstated back into your fridge - seems obvious, but worth mentioning.
How long is too long? It's the perfect follow up question, so let's have a look. A good answer is two weeks but it's not a "catch all" answer. Trutfully, so many environmental and cultural factors go in to the longevity (or lack thereof) in apples, that it's hard to pin down in a neat and tidy way. Each apple variety (and there are over 4,000) has its own quirks in regards to storage life. Fuji, for example, have a history of success in long term storage - maintaining crispness for months in your refrigerator. Some heirloom or heritage apples, Smokehouse for example, while delicious, do not keep well. The amount of moisture and rainfall during the growing season and the distribution of rainfall over time plays a huge factor in certain apple varieties keeping better in some years than others. Jonagold, one of my favorites, is a notoriously inconsistent keeper. Some years, they are great keepers, others not so much. Honeycrisp (everyone's favorite) is so finicky a keeper that the way we store ours is just about the only thing our farm values as a "trade secret" that you can't get out of me. Suffice it to say we go to great lengths to store Honeycrisp differently to preserve their awesome eating qualities. As chronicled in an earlier blog, apples stored in controlled atmosphere can maintain crispness for nearly a year without any sort of bizarre witchcraft (thanks to land grant ag research, of course). And while "storage apples" are representative of the fine work we do on this farm and I'll happily put our good name on them, I think we all agree - the closer to harvest the better. As it is with apples, so should it be with all of our eating.
Historically "Good Keepers"
Historically "Inconsistent Keepers"
Three Springs farmers market shopper and devoted cider enthusiast Erin writes:
"Hi, guys! We are drinking your delicious cider and having an animated conversation about what IS the difference between apple cider and apple juice (and we wondered), what's your opinion on this great debate?"
The question is a great one - and timely, since we were able to roll out a very popular Fuji Apple Juice for our customers this past spring. While the question was pretty clear (like the consistency of, say, apple juice), the answer is a little more murky and mysterious - a quality it shares with apple cider. We're gonna chew on this simple difference and spend a little time on how each is made in the hopes of providing some delicious distinction between the two!
On the surface, the two "apple-y" beverages are not very dissimilar. Both are pasteurized and list as their ingredients only "the juice of apples". As you can see, the difference between cider and juice is pretty minimal. The main difference is the apples used. For the purposes our discussion, I'll explain the difference in our cider and our juice. Our juice, typical of many juices, is a one variety product. We use only Fuji Apples in our juice. They are very sweet and make a palatable juice on their own. The Fuji apple juice is heated in excess of 200 degrees Fahrenheit so it can be shelf-stable bottled without the addition of any preservatives. This also effectively kills whatever bacteria and impurities the product could have contained. The resultant product is much lighter in color and consistency. We like the sweetness of the juice because we know kids love sweet beverages and we figure parents can dig it if they can serve their children a sweet beverage that comes from a local, sustainably raised farm and contains no added sugars! It's common for grocery store apple juices to be filtered to remove any hints and traces of apple sediment from the apple skins. Though they might seem visually unappeeling... er unappealing (can't believe I almost went there), the majority of an apple's nutrition is found in the skin, thus we leave it right where it is. Caveat Emptor: grocery store juices also commonly contain preservatives, sugar ("corn sugar" and otherwise), and apple juice concentrate - concentrate bottlers can import from Turkey, China, etc. without labeling as such.
Cider, on the other hand, is best enjoyed when many apple varieties are present. As a matter of fact, the sheer variety of apple flavors (in addition to Jonathan and other semi-tart base apples) is the not-so-well kept secret to our cider's success. It's cloudy, complex, tart and sweet, and contains all that valuable sediment. Our cider is also UV pasteurized, or "cold" pasteurized. This is vital to flavor preservation, in my opinion. This specialized UV has been proven by Cornell University to be equally effective in removing harmful bacteria as heat pasteurization. Not only is flavor preserved, but this product actively ferments, for all the homebrew/homewine enthusiasts out there which also means all the phytochemicals beneficial to the digestive system are also present!
So in summary, there's not a lot of difference between the two beverages. However, when they're done right, you should be able to tell easily. Juices are clearer in color and consistency - a lighter, monochromatic beverage. Ciders are bold, complex, dark, and more rich in flavor. By definition, they are nearly the same. In execution, they are worlds apart!
Stay tuned to this blog for fun, informative videos on this topic - debuting in the coming weeks!
further "Ask A Grower" readings:
- "Ask A Grower" vol. VII - Why Are Peaches Fuzzy?
- "Ask A Grower" vol. VI - Grafting Workshop
- "Ask A Grower" vol. V - Proper Apple Storage
- "Ask A Grower" vol. III - Clingstone Peaches vs. Freestone Peaches
- "Ask A Grower" vol. II - Granny Smith Fables
- "Ask A Grower" vol I - Roots & Scions
A curious web follower writes:
Legend has it that (Granny) Smith threw out cores and peels from some Tasmanian crabapples she'd used to make a pie. Since she and her husband were orchardists who grew apples themselves, surely there were domestic apple remnants in the compost pile as well.
Would a crabapple seed and a domestic apple seed both have sprouted into seedlings, then cross-pollinated? Does cross-pollinating have any effect on either variety's fruit, i.e. flavor, color, texture? Does cross-pollinating ever result in new cultivars?
Certainly there was no grafting involved, as Smith's seedling is said to have sprung up on its own, "accidentally."
I'm just wondering how this could have happened, technically.
Well, it's true that the parentage of the apple variety ("cultivar" to use a little grower speak) is credited to a chance seedling originating in Maria Smith's backyard in Austrailia. Before going on, the unlikelihood of this occurring cannot be understated - most seedling apple varieties are weird and unpalatable. The fact that such an apple did arise from such unlikely circumstances is truly remarkable. With that out of the way, let's wade through some somewhat fantastic exaggeration and figure out how varieties come from seed.
First things first, one cannot get a 'Granny Smith' tree from a 'Granny Smith' seed... or you're almost as likely to get that variety as any other. You would need to take a cutting of budwood from a 'Granny Smith' tree, as explained in "Ask a Grower, vol I". New varieties are mostly commonly derived from chance mutations ("tree sports" or "limb sports") or clever plant breeders, just to underscore the unlikelihood of valuable varieties coming from seed.
When an apple tree blooms, that blossom needs the pollen of at least one other compatible apple variety to fertilize the bloom and make a fruit. If you're planning an apple orchard, you must plan accordingly since apples are not self-fruitful. All of the different kinds of pollen on that bloom are combined inside the seeds when that fruit is made. How that pollen "jives" at fruit formation and what the resultant apple cultivar that seed might produce is a big crapshoot.
So if Granny Smith pitched Tazmanian apple cores into her Australian compost heap, that doesn't necessarily have anything to do with the apple we all enjoy today. The different varieties in the culls (to use another grower turn) is going to have little to do with tree that sprouts from the pile, aside from the seed had to have come from one of them.
So it's not rare that new apple varieties should come from seeds, though growing apple trees from seeds is often tricky. What is rare that an apple variety derived from a wild seed source be worth a darn, and 'Granny Smith' is!
Further "Ask a Grower" reading:
- "Ask A Grower" vol. VII - Why Are Peaches Fuzzy?
- "Ask A Grower" vol VI - Grafting Workshop
- "Ask A Grower" vol. V - Proper Apple Storage
- "Ask A Grower" vol. IV - All About Cider
- "Ask A Grower" vol. III - Clingstone Peaches vs. Freestone Peaches
- "Ask A Grower" vol I - Roots & Scions