Follow us on Twitter!

Categories
2008
2010
2011
2012
2013
2014
Adams County
ADHD
advocacy
Africa
ag
ag policy
apple
apple art
Apple Blossom Festival
apple juice
apple tree
apples
art
Ask A Grower
award
bad humor
Baltimore
baseball
beer
bees
Ben
berries
Biglerville
biology
birds
blog
bloom
blossoms
Brick and Mortar
brix
bulk
buyer's club
CA storage
Camp Hill
canned goods
canning
Carlisle
CCD
Central PA
certification
charity
cheese
Chef
Chefs
cherry juice
chilies
choosing
Chuck Darwin & The Knuckle Draggers
cider
Cider Fest
Cider Town
clingstone
cocktails
colorblind
Columbia Heights
concentrate
conservation
contest
cooking
craft beverages
crop diversity
customer survey
damage
Dave
DC
dining
dinner
discounts
Donald G. Wenk
drought
Dust Bowl
education
events
Fair Food Farmstand
Family History
FAQ
FAQ market
farm
Farm Dinner
farm history
farm labor
Farm Show
farm visit
farm workers
farmers
farmers markets
Farmers on the Square
Farmers on Walnut
food
Food Alliance
Food in Jars
food policy
Food Safety
food soverignity
food system
Food Tank
Food Tank Summit
Food Trust
FOTS
FREC
freestone
freeze
freezing
frost
fruit
fun
Future Harvest
FutureHarvest
fuzz
Gettysburg
Gift Baskets
Gift Boxes
Gifts
grafting
Granny Smith
Greenbelt
Grocery Store
growing
Growing Greener
Growing Practices
guide
guster
Harbor East
hard cider
harvest
Hawkeye
Headhouse
heirloom
heirloom apples
heirloom tomatoes
HHS
history
homebrew
homewine
Honeycrisp
hot
hot peppers
humor
IFTA
instagram
Intermarche
internship
IPM
John
juice
Ken Burns
Kenilworth
Kosher
Kosher Certified
lancaster
land access
LEAF
lightning
local
lysteria
Madam Fromage
Mark Bittman
market
marketing
markets
Maryland
Maryland Department of Agriculture
Maryland Farm to Chef
Master Farmer
mating disruption
maturity
MD
meetings
merlin
Muscle Bound Lummox
music
nectarines
Nerdy ag
NRCS
nursery
NYFC
Obama
oddity
offseason
One Straw Farm
online
online orders
online store
orchards
orders
organic
Organophosphates
Orioles
PA Apples
PA Cider Fest
pantry items
PASA
peaches
penetrometer
Penn State
Phillies
Philly
photos
pictures
planting
Ploughman
Ploughman Cider
pollination
preserving
President
press
pro food
produce
profood
PSU
raptors
Reading Terminal Market
recall
recipes
Red Delicious
refractometer
restaurant
restaurants
ripe
rodents
rootstock
Roy Orbison
science
scion
scouting
seconds
seedlings
Shane
SHAP
shipping
silly
Silver Spring
social networking
South Africa
starch iodine
STEM
storage
subsidies
survey
sustainability
sustainable
Tasting Menu
testimonials
The Atlantic
tomato
Tony Danza
tour
Towson
travel
tree
trees
Trini food
Trinidad
trivia
twitter
value added
varieties
video
visit
weather
White House
white peaches
wildlife
winter
winter markets
World Series
Year in Review
yellow peaches
YGA
ZA
zagat
Mailing list sign-up
<< Back to main

Nerdy Ag: vol IV Harvest Maturity 2

Posted 8/25/2016 8:36am by Ben Wenk.

NERDS!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. 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Nerdy Ag I - Harvest Maturity vol. 1

Nerdy Ag II - Frost Damage vol. 1

Nerdy Ag III - Frost Damage, vol. 2